Pomology
afsaneh Salehi; Fatemeh Nekounam; Farhang Razavi
Abstract
Introduction
Apple (Malus domestica) belongs to the Rosacea family and is one of the most important fruit trees in temperate regions. Apple fruit is a rich source of vitamins, sugars, organic acids, minerals, fibers, and bioactive compounds and is widely cultivated due to its pleasant taste, aroma, and ...
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Introduction
Apple (Malus domestica) belongs to the Rosacea family and is one of the most important fruit trees in temperate regions. Apple fruit is a rich source of vitamins, sugars, organic acids, minerals, fibers, and bioactive compounds and is widely cultivated due to its pleasant taste, aroma, and texture. Due to the rising need for food and fiber per unit of land area, chemical fertilizers are becoming increasingly popular to increase yields from small plots of land. Chemical fertilizers pose major health risks and harm the environment when they are used in excess. Because of this, research in this area is heavily focused on finding and evaluating the efficiency of new products. One such approach is using biostimulants that can enhance the effectiveness of conventional mineral fertilizers. Plant biostimulants contain some nutrients (marine plant extracts, humic acids, amino acids and other natural products such as saponins and compost teas) that stimulate plant growth, even when administered in small amounts. Foliar application of seaweed extracts at 0.2% recorded maximum no. of fruits/tree, fruit weight, and yield/tree in valencia orange.
Materials and methods
In order to investigate the effect of biofertilizers on growth, yield and leaf nutrient contents of apple under climatic conditions of Zanjan, the experiment was carried out in a completely randomized block design with three replicates in 2023. Different concentration of seaweed (Alg; 0.075 and 0.15%), amino acid (GF Amino; 0.1 and 0.2%), humic acid (HA; 0.3%), commercial fertilizer Homarang, (Homa fert; 0.5%), combined chemical fertilizer (nitrogen, zinc and boron (Combinate fert; 1% urea, 0.3% zinc chelate and 0.1% boric acid)) and distilled water as a control were sprayed on the trees at 40 days after full bloom stage until runoff using a mechanical mist sprayer, and repeated three times with an 30 days interval until the physiological ripening of fruits. The experiment was carried out on 10-year-old Red Delicious apple trees grafted on M9 rootstocks. Shoot length, chlorophyll index, fruit drop percentage, yield efficiency, leaf area, leaf dry matter, leaf macro and micro nutrient were measured. The analysis of variance (ANOVA) and least significant difference test (P≤ 0.05) used to compare means within each sampling date. The Statistical analysis and standard error calculation were carried out using SAS software (V. 9.3).
Results and Discussion
The results showed that the foliar application of bio and chemical fertilizers significantly increased growth and fruit yield. So that, the highest increase in shoot length (39%) and leaf area (74.30%) compared to the control was obtained with application of seaweed 0.075%. Also, seaweed 0.15%, amino acid 0.2%, humic acid and amino acid 0.1% caused a significant increase in leaf area (42.02, 35.57, 22.27 and 16.20%, respectively) compared to the control. Foliar spray of seaweed, amino acid and chemical fertilizer increased chlorophyll index. The highest increase in chlorophyll index (50%) compared to the control was obtained with application of combined chemical fertilizer at 130 days after full bloom. These results are in agreement with the outcomes of other experiments conducted with seaweed on apple and on other crops such as grapevine. Therefore, this represents a further evidence of a possible role of seaweed extracts in the reduction of chlorophyll degradation and in delaying leaf senescence. The highest amount of nitrogen (1.66%), potassium (1.03%) zinc (150 mg g-1DW) and boron (82.5 mg g-1DW) and the lowest amount of phosphorus (0.44%) were obtained with application of combined chemical fertilizer. The highest value of iron was observed in leaf of trees treated with seaweed 0.15%, humic acid and commercial biofertilizer. Based on the results, it was observed that the amino acid, seaweed and combined chemical fertilizer have the greatest effect in reducing fruit drop (36.97, 33.37, 29.07%, respectively) compared to control) and increasing yield efficiency (respectively 2.75, 2.73 and 2.8 compared to control with 0.22 fruits No. cm-2 SCSA). These results partially are in agreement with another research performed on apple, where the use of a similar seaweed extract (Ascophyllum nodosum) was found able to induce a higher final yield. The hormonal components found in the extracts, particularly cytokinins, are assumed to be responsible for the increased yield in plants treated with seaweed. Previous studies mentioned that the application of biological fertilizers alone or in combination with the mineral fertilizers had positive influences on the leaf plate area, mean fruit weight and fruit chemical composition.
Conclusions
According to the results of this research, the use of biofertilizers, especially seaweed (0.15%) and amino acid (0.1%), are suitable and nature-friendly substitutes for chemical fertilizers and can play a significant role in increasing growth indices and yield of apples.
Pomology
Seyed Asghar mousavi; Akram Vatankhah; Ali Imani
Abstract
Introduction
Almond is a commercial and important nut fruit known as Prunus dulcis, a species of Prunus of the Rosaceae family. The nutritional value of almonds as well as the presence of oil, protein, fiber, minerals and biologically active compounds have made almonds Nutrionally, industrially and medicinally ...
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Introduction
Almond is a commercial and important nut fruit known as Prunus dulcis, a species of Prunus of the Rosaceae family. The nutritional value of almonds as well as the presence of oil, protein, fiber, minerals and biologically active compounds have made almonds Nutrionally, industrially and medicinally important. In most native orchards of Iran, almonds are cultivated through seeds, which has increased the genetic diversity of this plant. The introduction and production of superior cultivars depends on the careful selection of plants, which requires knowledge of the cultivars and their diversity. Cross-pollination in almond increases genetic diversity in cultivated species. Creating a orchard by selecting grafted genotypes on suitable rootstocks for sustainable cultivation of almonds is particularly important (Babadai et al., 2017). The aim of this research is to evaluate the phenotypic diversity of 44 promising genotypes that were grafted on GF677 rootstock, using the vegetative, quantitative and qualitative characteristics of nuts and kernels in order to select superior genotypes. A great diversity was observed in the morphological and pomological characteristics of 60 almond genotypes by Ardjmand et al. (2014). Many researches (Mousavi et al., 2010; Asgari and Khadivi 2021; Heidari et al., 2022; Beigi and Khadivi, 2023) have been conducted on the selection of superior cultivars by examining the morphological, nut and kernel characteristics.
Materials and methods:
In this research, 44 promising almond cultivars and genotypes on GF677 rootstock were investigated in terms of various vegetative traits, nut and kernel characteristics. Experiment on 44 almond genotypes prepared from Karaj and grafted on GF677 rootstock, in March to September 2024 in the form of randomized complete block design in three replications at the almond research station in Saman region affiliated to the Chaharmahal and Bakhtiari Agricultural and Natural Resources Research and Education Center was conducted on 5-year-old trees. Vegetative traits of tree height, canopy length, canopy width, and branch length were measured by meter in the garden, and rootstock diameter, scion diameter, and branch diameter were measured in the garden with calipers. In order to measure nut and kernel traits, 100 fruits were harvested from each of the cultivars and genotypes, and their green shell was separated and dried. Measurement of traits such as length, width, diameter of nut and kernel was done by digital caliper and weight of nut and kernel was measured by digital scale with accuracy of 0.01. Coding of some traits was done based on almond descriptor (Gülcan, 1985) with some changes. The data obtained from the experiment were analyzed using SAS software (version 3.1.9). To compare the means, LSD least significant difference test was used at the 5% probability level.
Results and Discussion
The results of analysis of variance for the evaluation of vegetative traits showed that there was a significant difference between promising cultivars and genotypes in terms of tree height, canopy length and canopy width, one-year branch length, canopy length-to- canopy width ratio, and canopy height-to- canopy length ratio at the 1% probability level. The results of the analysis of variance showed that between all cultivars and genotypes grafted on GF677 rootstock in terms of length, width, diameter and weight of nuts, length, width, weight and diameter of kernel, shell thickness, double kernel, percentage of blank kernel, kernel color and shrinkage of kernel, shell hardness, suture opening of the shell, percentage of kernel, kernel width/kernel length ratio, kernel thickness/kernel length ratio, kernel thickness/kernel width ratio and kernel weight/nut weight ratio have significant differences. Based on the obtained results, the genotypes 4-4, TS-11, H, 2-3-2, 2-0-4 according to the valuable and commercial properties of almonds, including yield, kernel percentage, shell hardness, percentage of blank kernel, kernel weight, suture opening of the shell, double kernel, shell thickness, kernel color and most importantly late flower were genotypes with relative superiority in terms of nut and kernel traits. According to the results, the 4-4 genotype grafted on the GF677 rootstock with yield of 750 gr, 51% kernel percentage , hard shell, excellent seal suture opening of the shell, very light kernel color, late flowering, flowering on spurs and one year old shoots, the low of double kernel and low percentage of blank kernel seems to be one of the relatively good genotypes for Chaharmahal and Bakhtiari region. In the study of Mousavi et al., 2010, by examining the quantitative and qualitative characteristics of 55 varieties and genotypes of almonds, reported that all quantitative and qualitative traits in the genotypes have significant differences, which is in line with the results of this research.
Conclusion
Based on the results of this study, significant variation in morphology, phenology, and pomology was observed among 44 promising genotypes grafted onto GF677 rootstock. This variation is of great importance in selecting superior cultivars that are adapted to environmental conditions, as well as in selecting high-yielding genotypes. Chaharmahal and Bakhtiari province, with its specific climatic conditions, requires varieties that are adapted to these conditions. The climatic conditions of this region include hot and dry summers and cold winters, so varieties that are resistant to cold and drought should be selected, especially varieties whose flowering date is such that they are safe from the risk of spring frost. Based on the obtained results, the genotypes 4-4, TS-11, H, 2-3-2, 2-0-4 according to the valuable and commercial properties of almonds, including yield, kernel percentage, shell hardness, percentage of blank kernel, kernel weight, suture opening of the shell, double kernel, shell thickness, kernel color and most importantly late flower were genotypes with relative superiority in terms of nut and kernel traits. According to the results, the 4-4 genotype grafted on the GF677 rootstock with yield of 750 gr, 51% kernel percentage, hard shell, excellent seal suture opening of the shell, very light kernel color, late flowering, flowering on spurs and one year old shoots, the low of double kernel and low percentage of blank kernel seems to be one of the relatively good genotypes for Chaharmahal and Bakhtiari region.
Pomology
Vali Rabiei; Sogra Heydari; Asghar Soleimani; Fahime Nasr
Abstract
Introduction
The Persian walnut (Juglans regia L.) is a valuable commercial crop with high economic and nutritional value. Nutrition management is one of the most important factors affecting the growth and performance of modern walnut orchards. The demand for high-quality walnuts is increasing day by ...
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Introduction
The Persian walnut (Juglans regia L.) is a valuable commercial crop with high economic and nutritional value. Nutrition management is one of the most important factors affecting the growth and performance of modern walnut orchards. The demand for high-quality walnuts is increasing day by day in the national and international markets. Horticultural production has undergone tremendous changes in recent years due to the development of innovative technologies, including nutrient management practices. Nutrient management of walnuts is one of the important factors for increasing yield and improving the quality of walnut kernels. The use of nitrogen, phosphorus and potassium fertilizers is essential for tree growth and the production of fruits such as walnuts. The enhancement in the use of fertilizers in an irrational manner has led to a decrease in soil productivity and multiple nutrient deficiencies. Minimizing the use of chemical fertilizers in fruit cultivation is the goal of integrated fruit production. The gravity of environmental degradation caused by the faulty cultivation practices has led to focus on ecologically sound, viable and sustainable farming systemsIn this study, in order to investigate the efficiency and feasibility of replacing sulfate-containing fertilizers with thiosulfate-based fertilizers, the effect of calcium thiosulfate and potassium thiosulfate fertilizers on increasing the yield and quality of walnut fruit was evaluated in an experiment.
Materials and Methods
This experiment was conducted in 1402, in a randomized complete block design with three replications and 5 trees per experimental unit in an orchard with 6-year-old Chandler trees grown from tissue culture seedlings in the Khoramdareh Agro-Industrial Complex. The experimental treatments included T1: regular orchard nutrition (control) including 50 kg/ha potassium nitrate calcium + 200 kg/ha potassium sulfate, T2: 100 L/ha calcium thiosulfate plus 200 kg/ha potassium sulfate, T3: 50 kg/ha potassium nitrate and calcium plus 100 L/ha potassium thiosulfate plus 125 kg potassium sulfate, T4: 100 L/ha calcium thiosulfate plus 100 L/ha potassium thiosulfate plus 125 kg potassium sulfate. After applying the treatments, after observing signs of ripening, the fruits of the tree were harvested and transferred to the laboratory for evaluation of biochemical and physical traits.
Results and Discussion
Analysis of variance for fruit and yield traits showed significant differences at the 1 and 5 % levels. Comparison of the means of these traits showed that the highest fruit dry weight, fresh and dry kernel weights, and kernel percentage were obtained in the calcium and potassium thiosulfate treatment, and the highest tree yield and yield efficiency per trunk cross-section were obtained in the calcium thiosulfate treatment. Calcium increases the growth of hairy roots, root cell division, root length and also enhance the absorption and transfer of nutrients and water to the plant, This led to an improvement in fresh and dry weight of the plant and yield. Calcium also increases the fresh and dry weight of the plant by increasing the transfer of carbohydrates from leaves to fruit. On the other side, potassium increases fresh and dry weight and yield by enhancing photosynthesis, carbohydrate formation and transport, maintaining intracellular pH, and absorbing nutrients from the soil. In addition, the results of the comparison of means showed that all treatments used increased the total phenol and flavonoid content of walnut fruit compared to the control, so that the highest total phenol and flavonoid content were obtained in the potassium thiosulfate and potassium and calcium thiosulfate treatments. Calcium reduces oxidative stress in the membrane through membrane strength and delays the degradation and reduction of phenolic compounds by strengthening the membrane and cell wall. Moreover, Potassium increases plant growth and photosynthetic activity, increasing the allocation of additional carbon to the shikimic acid pathway, thereby increasing phenolic substances such as phenols and total flavonoids. Potassium also increases phenolic compounds and antioxidants by increasing the activity of the enzyme phenylalanine ammonia lyase, which is a key enzyme in the synthesis of phenolic compounds. Analysis of variance of data related to crude fiber, total protein and crude fat of fruit showed significant difference between treatments at 1% level, but the effect of treatments on ash content of samples was not significant. Results of mean comparison showed that the highest amount of crude fiber was related to potassium and calcium thiosulfate treatment. Increased absorption and transport of nutrients is one of the important factors in increasing crude fiber in plants, and it seems that rapid absorption and transport of thiosulfate-containing compounds has led to improved fiber production. Analysis of variance of data related to linoleic and oleic acid traits of walnut fruit showed significant difference between treatments at 1% level and results of mean comparison also showed significant increase in linoleic acid content in fruits under calcium and potassium thiosulfate treatment and potassium thiosulfate treatment. There are two important sources for assimilation and oil formation. The first is the carbohydrate pathway that is produced in the leaf after photosynthesis and transferred to the fruit, and the second is the carbohydrate pathway that is formed during photosynthesis in the walnut fruit, which is converted into fatty acids after enzymatic processes. In this study, increasing sulfur, potassium, and calcium and increasing the absorption of trace elements due to thiosulfate consumption increased photosynthetic activity and increased the production of plant metabolites, which increased the fatty acids in walnuts. Therefore, the obtained results indicate high efficiency of calcium and potassium thiosulfate fertilizers in increasing quality and yield of walnut fruit.
Conclusions
Our findings indicated that calcium thiosulfate - potassium thiosulfate combination were the best treatments for increasing quantitative and qualitative characteristics of walnut fruit. These findings demonstrate the potential of calcium and potassium thiosulfate fertilizers to enhance walnut orchard productivity and fruit quality, making them a recommended choice for nutrient management strategies.
Keywords: Fatty acids, Nutrition, Biochemical traits of fruit, Yield efficiency
Pomology
F. Nekounam; A. Salehi
Abstract
Introduction
Apple (Malus damestica L.) is one of the most popular temperate fruits in the world as well as Iran. One of the challenges in managing apple orchards is excessive fruit formation or excessive fruit drop especially in the pre-harvest stage, which affects the performance and marketable product. ...
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Introduction
Apple (Malus damestica L.) is one of the most popular temperate fruits in the world as well as Iran. One of the challenges in managing apple orchards is excessive fruit formation or excessive fruit drop especially in the pre-harvest stage, which affects the performance and marketable product. Therefore, the control fruit set is required to help regular fruit production. Currently, the application of synthetic auxins as plant growth regulators are successfully practiced and mainly used in various countries, including all aspects of modern apple production to control and manipulate vegetative growth and regulation of flowering, reduce immature fruit drop, fruit maturity, firmness, and manage apple harvest. Among the auxin-type growth regulators, NAA is a synthetic auxin analogue that may down-regulate abscission-related genes and reduce the sensitivity of the abscission zone to ethylene. It has long been used to reduce or totally prevent pre-harvest fruit drops, to preserve fruit flesh firmness, and to prevent starch degradation in apples. Therefore, this experiment was conducted to evaluate the effects of foliar application of NAA at different days after full bloom on controlling fruit drop and enhancing the physical and biochemical attributes of ‘Red Delicious’ apple fruits. The findings presented here may improve understanding of the impact of this plant growth regulator on apple quality and contribute to developing strategies to reduce postharvest losses.
Materials and Methods
In order to study the effect of NAA on controlling fruit drop, fruit yield and quality, a factorial experiment based on randomized complete blocks design with three replication was conducted under Zanjan climatic conditions during 2023. Ten year-old ‘Red Delicious’ Standard apple trees grafted on M.9 rootstock were used as plant material. Treatments consisted of different concentration of NAA (15, 30, 50 and 75 mg.L-1) sprayed at different days after full bloom (10, 25 and 40 DAFB). The date of full bloom was 04/22/2023. The fruit growth pattern was based on fruit weight and diameter during DAFB. According to fruit growth pattern, fruit were harvested at physiological maturity stage. Fruit number per replicate, fruit weight, diameter and shape index, fruit firmness, total soluble solids content and taste index were measured. Also, fruit drop percentage, fruit yield as well as fruit efficiency was estimated.
Results and Discussion
Advanced knowledge of apple fruit development from fruitlet to maturity is crucial for optimal prediction of year-to-year yields and fruit quality. Apple fruit growth has been defined as sigmoidal increase in fruit diameter or fresh weight. Studying two fruit growth patterns based on fruit weight and diameter data showed that fruit weight is a more appropriate indicator for drawing fruit growth patterns, and according to that, the fruits were harvested at the physiological maturity stage. Foliar spray of NAA during different DAFB showed different significant effects on fruit drop and yield efficiency. The highest rate of fruit drop (95.7 % and 85.9 %) was observed with foliar application of NAA at 10 and 25 DAFB, respectively, but its application at 40 DAFB reduced fruit drop by 46.9% compared to the control, and correspondingly the fruit yield increased by 22% compared to the control treatment. The lowest number and weight of fruits per unit shoot cross sectional area was observed in trees treated with different concentrations of NAA at 10 DAFB. The maximum fruit length (72.3 mm), diameter (75.8 mm), weight (180 g) and fruit volume (240 cm3) were obtained with application of 75 mg L-1 NAA at 10 DAFB. The foliar spray of NAA at 10 DAFB significantly increased the fruit density, flash firmness and TSS. But their use in 25 and 40 DAFB had no significant effect on fruit density and flash firmness, and significantly decreased fruit TSS by 23.9% compared to the control trees. Unlike the TSS, the value of fruit titratable acidity showed a significant increase in all three times of naphthalene acetic acid treatment compared to the control, and as a result, the fruit taste index decreased.
Conclusions
The present study concluded that the positive effects of NAA in controlling fruit drop and improving the yield and fruit quality will be different depending on the time of application and the weather conditions of the region under study. According to the results, the application of NAA at 40 DAFB reduced fruit drop and increased fruit yield efficiency.
Pomology
S.A. Mousavi; M. Tatari
Abstract
Introduction
Peach×almond (GN) hybrid rootstocks have favorable characteristics such as ease of rooting, favorable growth vigour, resistance to nematodes, calcareous and dry soil (Babadaei et al., 2018). Currently, water deficiency caused by reduced rainfall is a major concern and a critical limitation ...
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Introduction
Peach×almond (GN) hybrid rootstocks have favorable characteristics such as ease of rooting, favorable growth vigour, resistance to nematodes, calcareous and dry soil (Babadaei et al., 2018). Currently, water deficiency caused by reduced rainfall is a major concern and a critical limitation for agricultural production (Hass et al., 2021). Under drought stress, plant cell membranes become more susceptible to electrolyte leakage. Membrane leakage is caused by uncontrolled free radicals and leads to lipid peroxidation (Cheng et al., 2018). Since tolerance to drought stress is the result of the interaction of morphological and physiological traits of plant, therefore, a combination of different traits that have a direct relationship with drought tolerance can be used as selection criteria to screen the ideal cultivar (Karimi et al., 2015).
Materials and Methods
This research carried out during the years 2020 and 2021 at the Chahartakhteh station affiliated to the Center for Research and Education of Agriculture and Natural Resources in Chaharmahal and Bakhtiari Province. The almond seedlings included Shahroud 6, 7, 8, 10, 12, 13 and 21, that all of them grafted on the GN rootstock, along with GN rootstock, subjected to different drought stress treatments in June for four months. Drought stress treatments included 70% of field capacity (control or no drought stress), 50% field capacity (mild stress), 30% field capacity (moderate stress) and 10% field capacity (severe stress). A counter determined the amount of irrigation in each treatment, and a Time-Domain Reflectometry (TDR) used to measure the soil moisture. Before the experiment, the physicochemical properties of the soil measured. The measured morphological traits included leaf area, percentage of leaf abscission, and shoot fresh and dry weight. These traits measured four months after subjecting to water stress. The evaluated physiological traits included electrolyte leakage (EL), relative leaf water content (RWC), leaf chlorophyll, proline and malondialdehyde (MDA). These traits also measured four months after subjecting to water stress. The experiment conducted in split plots based on a randomized complete block design in three replications and four seedlings in each experimental unit. The main plot included water drought treatments and the sub plot included almond cultivars. Data analysis carried out using SAS software version 9.2 and comparison of mean data conducted based on LSD test at a five percent probability level.
Results and Discussion
As the intensity of drought stress increased, the fresh and dry weight of shoot decreased in almond cultivars and GN rootstock. At soil humidity of 10% field capacity, Shahroud 8 showed higher amounts of shoot fresh weight (785 g). The lowest fresh and dry weight of the shoot and the highest leaf abscission were observed under severe drought stress (10% of the field capacity) in Shahroud 13. The increase in drought levels led to a decrease in the leaf area in the studied cultivars and rootstock of almond. Shahroud 8 had more chlorophyll content than other cultivars at the most severe stress level, and Shahroud 13 showed the lowest chlorophyll b content at 10% humidity of field capacity. A significant decrease in leaf chlorophyll concentration under drought stress has also been reported in previous research (Schlemmer et al., 2005; Gohari et al., 2023). A further decrease in chlorophyll could be due to a drastic decrease in RWC under severe stress conditions. According to Ranjbar et al. (2022), the amount of RWC decreased by 32 to 44% under stress conditions in the K13-40 grafted cultivar on the rootstock of bitter almond No. 32. In the current research, the biggest decrease in RWC was in Shahroud 13 with a decrease of 36.85%. The lowest decrease in RWC was also observed in the GN rootstock with a decrease of 20.94%. Shahroud 13 and GN rootstock showed the highest and lowest electrolyte leakage at the highest stress level, respectively. Karimi et al. (2013) also found a significant increase in EL in White, Mamai and Ferragnes cultivars due to the higher sensitivity of these cultivars to water loss. The most difference in MDA value was observed in Shahroud 13 with an increase of 186.35% and the lowest difference was found in Shahroud 10 with an increase of 84.58%. Shahroud 6 produced the highest content of proline under severe water stress. According to the results, Shahroud 13 and then Shahroud 6 were recognized as the most sensitive cultivars. Shahroud 8 and 12 were among the tolerant cultivars. Other cultivars were also between these two groups.
Conclusions
Shahroud 13 was recognized as the most sensitive cultivar with the lowest fresh and dry weight, RWC and the highest ion leakage and MDA at the most severe stress level. After that, Shahroud 6 had high sensitivity. Shahroud 8 was recognized as the most drought tolerant cultivar due to its lowest MDA content, the highest chlorophyll a and b and RWC in the most level of drought. After Shahroud 8, Shahroud 12 was including the tolerant cultivars. Tolerant cultivars can be used in future studies to evaluate the possibility of planting these cultivars in areas with water shortage problems.
Pomology
M. Ghazaeian; D. Hassani; S. Zamani; M. Adibi
Abstract
Introduction
The Juglandaceae family includes about 50 species of 11 genera of which Carya (hickory tree), Pterocarya (wingnut tree), and Juglans are the major members. The pecan, Carya illinoinensis is the most economically important member of the Carya genus and is the most valuable native North American ...
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Introduction
The Juglandaceae family includes about 50 species of 11 genera of which Carya (hickory tree), Pterocarya (wingnut tree), and Juglans are the major members. The pecan, Carya illinoinensis is the most economically important member of the Carya genus and is the most valuable native North American nut crop. The Carya genus comprises 20 species.
Materials and Methods
Golestan province is located in the northern temperate region between 37.2898° N, 55.1376° E from the Greenwich meridian and in the northern part of the country. The amount of precipitation reaches 200 mm in the northernmost part of the province and more than 700 mm in the southern parts of Alborz foothills. Temperature varies across different parts of the province, generally increasing from west to east and from south to north. The genotypes used in this project are G4, G3, G43, G63, which were selected and propagated from the elite trees available in the province after quantitative and qualitative evaluation, and the cultivars are Mahan and Comanche, which were propagated from grafted trees of the Dezful Research Center collection. Grafted seedlings were produced using thethermal cable technique and planted in the specified locations in the above 2 regions. Grafted trees from 4 elite genotypes of Golestan (G4,G3,G43,G63) plus Comanch and Mahan 2 commercial cultivars have been studied in randomized completely block design (RCBD) for 3 years in two regions. In the second phase of experiment, the fruit characters and yield evaluated based on pecan descriptor. The results were analyzed by SAS statistical software and the reactions of genotypes were evaluated in different places and during different years.
Results and Discussion
This evaluation was conducted during the years 2021 to 2024 at Chalki research station of the Golestan Agricultural and Natural Resources Research and Education Center in Gorgan and on the farmer's land located in Igder village, located 30 km from Gonbad city. Measurements were conducted on fruits harvested in 2022 and 2023. During both years, the Mahan cultivar did not produce a sufficient number of fruits in either region and was therefore excluded from the comparison. A significant effect of location and year was observed only for the fruit weight trait. Among the genotypes, G43 exhibited the highest fruit weight (11.75 g) and demonstrated vigorous growth with a broad canopy in both locations. However, fruit yield over the two years of evaluation showed no significant differences among the studied cultivars and genotypes across the two regions.Due to the results of the first phase, the maximum tree height was in Mahan (242.5 cm) and the lowest height in G63 (118.66 cm). The maximum canopy spread was in comanch (138.72 cm) and the lowest was in G63 (90.11 cm).There were significantly differences between two regions. The length of the growing season among cultivars was 257 days in Gonbad and 237 to 247 days in Gorgan. Study of dichogamy during the years 2021-2022 in the cultivars and genotypes showed two cultivars Comanche and Mahan were protandry in Gorgan, while both cultivars showed protogyny in Gonbad. Also, 4 genotypes of the province (G3, G4, G43, G63) showed protogyny.
Conclusions
This project, conducted over both vegetative and reproductive phases, evaluated elite pecan germplasm within the province. The objective was to utilize the region’s existing genetic potential and to compare it with commercially available cultivars in the country, with the goal of identifying and promoting superior genotypes for the establishment and expansion of new orchards in Golestan Province. The results of the two phases of this research showed that some of the introduced genotypes have the ability to compete with the existing commercial cultivars, which will require further investigation in the years of peak fruiting and maturity of the tree. The length of the growing season among cultivars was 257 days in Gonbad area and 237 to 247 days in Gorgan. Also, the effects of drought conditions in Golestan province during 2021-2022 should be included in the relative determination of the results. As a summary, based on the evaluation of these two phases and considering the growth and fruiting conditions, two genotypes G4, G43 and G63 can be considered as promising genotypes for development.
Acknowledgement
The authors consider it necessary to appreciate the support of Horticultural Sciences Research Institute (HSRI) and Golestan Agriculture and Natural Resources Research and Education Center in the implementation of this project.
Pomology
S. Keivanfar; D. Hashemabadi; B. Kaviani
Abstract
IntroductionOlive (Olea europea L.) fruit ripening is a slow and long process and has a great impact on fruit quality, including the amount of oil. Also, interrupting the harvest and extraction of olive oil causes unfavorable conditions in this fruit. Therefore, it is important to determine the best ...
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IntroductionOlive (Olea europea L.) fruit ripening is a slow and long process and has a great impact on fruit quality, including the amount of oil. Also, interrupting the harvest and extraction of olive oil causes unfavorable conditions in this fruit. Therefore, it is important to determine the best time to harvest the fruit. Olive oil has unsaturated fatty acids and has an antioxidant activity. The analysis of maturation stages is a prerequisite for fruit harvest time in each cultivar and quality of olive products. The time of harvest and maintenance after harvest is two important factors in the quality and quality of olive fruit oil. The exact determination of olive harvest time depends on the geographical area, cultivar and climate, agronomic and fruiting conditions. Study on different olive cultivars in different regions of Iran and the world revealed that fruit harvest time plays an effective role on the morphological, physiological and metabolic parameters of fruit. The approximate time of olive fruit harvest is in different geographical points, November and October. The purpose of this study was to investigate the right time of olive fruit harvesting 'Arbequina' and 'Yellow' cultivars for obtaining maximum quality of fruit and oil. Materials and MethodsA factorial experiment containing two factors; cultivar in two levels ('Yellow' and 'Arbequina') and harvest time in six levels (24th and 31th October, and 7th, 14th, 21th and 28th November) based on a completely randomized block design with two factors in 12 treatments, 3 replicates and 36 experimental units was done to determine the appropriate harvest time and its effect on oil quality. Physiologic parameters; percentage of oil, amount of phenolic compounds, degree of peroxidation, amount of oleic acid, force of separation of fruit from tail and acidity were evaluated. This research was conducted at the olive research station in Rudbar city in southern Guilan province using the removed olives from the Manjil ETKA station. The 6 trees from two cultivars; 'Arbakkin' and 'Yellow' (from each 3 tree) which were similar in terms of height, age, crown diameter, mean conditions and irrigation were evaluated. Trees were planted at 6 × 8 m intervals. After selecting trees, from each tree, 2 to 3 kg of olive was randomly harvested. In fruits with tail, the force needed to separate the tail of the fruit was measured by the force assessment device. Standard method numbers 4178 and 4179 standard institutes and industrial research of Iran were used to measure acidity and olive oil peroxide, respectively. Polyphenols were measured with spectrophotometer. To determine the percentage of oil, saccule was used. For measurement of oleic acid, gas chromatography (GC) was used. Data were analyzed using SAS software and their average comparison was done by Duncan. Results and Discussion Mean comparison of the interaction effect between cultivar and harvest time showed that the highest acidity of the fruit was obtained in 'Arbequina' cultivar, respectively harvested at two times 31th and 24th October. The highest fruit peroxide value and the highest percentage of oleic acid were calculated in 'Yellow' cultivar in 24th October. The highest value of polyphenol was obtained in 'Yellow' cultivar on 7th November. The highest percentage of fruit oil was obtained in 'Arbequina' cultivar on 31th October. The lowest force to separate the tail from the fruit was applied in 'Arbequina' cultivar on 31th October. The results showed that the best time to harvest 'Yellow' cultivar is 7th November and for 'Arbequina' cultivar is 14th November. The study on several olive cultivars in China showed that the most suitable fruit harvest time was in late October until mid-November. There was an adverse significant correlation between changes in total sugar content in fruit and leaf and oil accumulation in the fruit. The quality of fruit depends mainly to the type of cultivar, genetic characteristics, maturity and environmental conditions. Study on some olive cultivars showed that the ratio between sugars is different in various stages of fruit maturity and between different cultivars of olive fruit. Some studies have shown that the most suitable time of olive fruit harvest for canned preparation is early September and for extraction of oil, late September. Fruits should be harvested when they have the highest oil accumulation. The study on 'Koroneiki' and 'Mission' cultivars in Gorgan region showed that the amount of oil in the dry matter and the percentage of free fatty acids increased with increasing degree of maturity, while peroxide value was reduced. One of the causes of peroxide value reduction during maturity is reduction in lipoxygenase enzyme activity. This enzyme increases the peroxide value by effect on linolenic acid and linoleic acid. Based on these results, the best time to harvest for the above cultivars is early in December. ConclusionsHarvest time and proper storage after harvest are two important factors of olive oil quantity and quality. In both cultivars, a longer delay in harvesting compared to the mentioned-above dates increases the percentage of oil, but it has a negative effect on the reproductive stages of the next year, and perhaps one of the causes of olive aging is excessive delay in harvesting. It is important to pay attention to the above two items.
Pomology
S. Fatahi Siahkamary; V. Rabiei; M. Shoor; S. Nicola
Abstract
Introduction
The Lycium genus of the Solanaceae family has excellent nutritional and medicinal value. Two species of Lycium barbarum L. and Lycium chinense Mill. It is often called wolfberry or goji berry. The use of amino acids for horticultural crops is common worldwide, and many chemicals used as ...
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Introduction
The Lycium genus of the Solanaceae family has excellent nutritional and medicinal value. Two species of Lycium barbarum L. and Lycium chinense Mill. It is often called wolfberry or goji berry. The use of amino acids for horticultural crops is common worldwide, and many chemicals used as biostimulants are mixtures of amino acids. The effect of amino acids on plants seems to depend on the type of amino acid supplied and the type of plant. Selenium (Se) is an important component of selenoproteins and seleno-amino acids. Therefore, it has played many roles in the growth and function of living cells and important biological functions in animals and humans. Also Se is very similar in properties to sulfur and can act as S in biochemical systems. Biological fertilizers are fertile materials that contain one or more beneficial soil organisms within a suitable carrier. Overall, these fertilizers contain different types of microorganisms that can convert nutrients from unavailable form to available form through a biological process. The application of supernitroxin fertilizer by stimulating the synthesis of plant hormones increased the growth indicators of sesame varieties.
Materials and Methods
This experiment was conducted at the Research farm University of Mashhad, during 2021 and 2022 years. In early May, goji berry seedlings were planted in the field to check the effect of the L-phenylalanine (Phe), sodium selenate (Se), and nitroxine were applied before harvesting and foliar spraying on the goji berry plant during the growth stages. To conduct experiment, two-year-old seedlings of Goji berry cultivar GB1 were obtained from Mashhad Seedling Company located in Razavi Khorasan province, and after the seedlings were transferred to ground and established, initial foliar spraying was done. In order to evaluate the effect of L-phenylalanine, selenium, and nitroxine treatments, experiment were conducted as a randomized complete block design in 5 replications which factors include the amino acid L-phenylalanine (Phe: 0.5, 1, and 1.5 mM), sodium selenate (Se: 0.25, 0.5, and 1 mg.L-1) and nitroxin biological fertilizer (170, 330, and 500 μl.L-1) at three levels and distilled water was applied as a control. One pot was considered for each repetition and a total of 10 pots were considered along with the control. Plants were sprayed every 15 days after establishment. After the three stages of foliar spraying, the content of phenol and flavonoid content and antioxidant activity, PAL and anthocyanin were measured.
Results and Discussion
The results showed that the treatments used in this experiment had a significant effect on the physiological and chemical characteristics of the goji berry plant. The results showed that the highest amount of titratable acidity (0.896%) was obtained in samples treated with nitroxine at a concentration of 333 microliters. The highest amount (18.56 mg.g-1) of this index was obtained in fruits treated with phenylalanine at a concentration of 1.5 mM. The highest amount of this index was obtained in the fruits treated with phenylalanine at a concentration of 1 mM, which was 61.98% higher than the amount of flavonoid recorded in goji berries under control conditions. Also, the results showed that despite the decrease in the activity of PAL enzyme during the increase of selenium concentration, the activity of this enzyme was 13.66% higher than the activity of PAL enzyme under the condition of using selenium at a concentration of 1 mg/liter. The increase in the functioning of the antioxidant system is determined by the total antioxidant, which is controlled by the content of low-molecular components and the activity of antioxidant enzymes. Compounds such as ascorbic acid, glutathione, tocopherol, carotenoids, anthocyanins, endogenous metal chelators, TPC, TFC and alkaloids are low molecular weight antioxidants. Also nitroxin, supernitroplus, phosphate and mycorrhizal fertilizers. Nitroxin binds N in the atmosphere and balances the absorption of nutrient element in the plant. Nitroxin is responsible for the secretion of amino acids, antibiotics, hydrogen cyanide and siderophores, which promote the growth and development of plant roots and shoots, protect the roots from pathogens, thereby increasing yield. A sufficient supply of phenylalanine through the use of exogenous Phe or endogenous Phe provided by the shikimic acid pathway may be required to stimulate the activity of the phenylpropanoid pathway, as shown by the high PAL activity responsible for the accumulation of phenols, flavocyanins and anthocyanins. This leads to the need for ROS accumulation. Anthocyanins are groups of flavonoids found in vacuoles epidermal and mesophyll cells of plants. Anthocyanins can protect chlorophyll from light oxidation and, compared to other components, is a better indicator of plant oxidative stress caused by external factors that accumulate in plants.
Conclusions
The present study was conducted with the aim of studying the effect of L-phenylalanine, selenium and nitroxin biofertilizer on improving the vegetative growth, yield and secondary metabolites of gojiberry during two cropping years. To conduct the experiment, two-year-old seedlings of Goji berry variety GB1 were obtained from Mashhad Seedling Company located in Razavi Khorasan province. The results demonstrated that the application of L-phenylalanine amino acid, selenium, and nitroxin biofertilizer significantly influenced the traits studied during the experiment. Specifically, nitroxin at a concentration of 166 microliters increased the amount of soluble solids, while at a concentration of 333 microliters, it elevated titratable acidity compared to the control samples. The highest PAL enzyme activity was observed with phenylalanine at a concentration of 1.5 mM, showing a 52.17% increase compared to the PAL enzyme activity under control conditions.
Pomology
S. Karami; S. Faraji
Abstract
Introduction
Mineral nutrients (macro and micro) and polyphenolic compounds are natural components of many fruits and play an important role in maintaining the quality and nutritional value of the fruit. Therefore, optimal management of plant nutrition in order to increase the quantity and quality of ...
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Introduction
Mineral nutrients (macro and micro) and polyphenolic compounds are natural components of many fruits and play an important role in maintaining the quality and nutritional value of the fruit. Therefore, optimal management of plant nutrition in order to increase the quantity and quality of the product and improve the synthesis of secondary metabolites, especially during fruit growth, is necessary and unavoidable. Nevertheless, in the last decade, the occurrence of pomegranate (Punica granatum L.) aril paleness has been reported as a new and pervasive factor in reducing the quality of pomegranate fruit in many countries, including Iran. The present research was conducted with the aim of comparing the mineral concentrations (iron, zinc, and calcium) and biochemical characteristics (anthocyanin content) in pomegranates affected by aril paleness and healthy pomegranates of the ‘Malase Saveh’cultivar (2022). Additionally, the study aimed to investigate the effect of foliar application of the mentioned mineral elements on the incidence and severity of the aril paleness condition (2023).
Materials and Methods
This study was carried out during two years (2022 and 2023) and two independent trials. First, based on the introduced factors affecting the occurrence of pomegranate paleness (temperature, irrigation water and soil salinity), two orchards with medium and high percentage of pomegranate aril paleness (orchard number 9 and 17, respectively) were selected based on the results of Faraji & Karami (2024a). The first trial in 2022 (orchard No. 9): At harvest and after splitting fruits, twenty healthy fruits and affected fruits by the aril paleness disorder were randomly selected and were used for determination of mineral nutrient (Fe, Zn and Ca) and anthocyanin content in the laboratory. The second trial in 2023 (orchard No. 17): In the first phase, 70 trees were selected and labeled, then at the end of September (2022), percent and severity aril paleness of each tree was calculated. In the second phase (2023), based on the results of the first year, 54 trees as experimental unit (with aril paleness percentage>85 and paleness severity of high/very high) were selected from previous trees. Afterwards, a factorial experiment (3×3×2) based on a randomized complete block design with three replications and two stages (the beginning of fruit set and the beginning of fruit ripening) were implemented. Experimental treatments included foliar spraying with three concentrations of iron sulfate (0, 2 and 4 per thousand respectively F0, F2 and F4), three concentrations of zinc sulfate (0, 3 and 6 per thousand respectively Zn0, Zn3 and Zn6) and two concentrations of calcium chloride (0 and 4 per thousand respectively Ca0 and Ca4). Then at harvest, the percentage and severity of aril paleness each treatment was calculated.
Results and Discussion
Data analysis using the independent t-test (α=0.05, df=38) for the first trial (2022) showed that, the nutritional value of the affected fruit by aril paleness is anticipated to be far less than that of the healthy fruit; so that except for the Zn concentration, the concentration of Fe, Ca and anthocyanin content in affected fruits were lower than in healthy fruits. The results of the variance analysis for the second trial (2023) indicated that foliar spraying with iron sulfate, zinc sulfate, and calcium chloride, either individually or in combination, was effective in reducing the occurrence and severity of aril paleness. A comparison of the mean percentage of aril paleness between the two groups (before and after foliar spraying, regardless of the treatment combination) using a dependent t-test (α=0.05, df=16) also showed that foliar spraying was effective in reducing the percentage of aril paleness. Furthermore, the involvement of calcium in reducing the incidence and severity of aril paleness was found to be significant. In the absence of calcium element, the incidence of paleness was recorded in the range of 60.17-75.00%, and with the inclusion of calcium in the treatment compounds, the percentage of paleness was recorded in the range of 21.83-0.53%. Also, the mean comparison of the double interaction and main effects of elements indicated the synergistic effect of calcium element with Fe and Zn element in reducing the aril paleness disorder. So that, the combination of Fe-Ca and Zn-Ca has been more successful in reducing the aril paleness disorder than the pure application of each element of iron, zinc and calcium.
Conclusions
Overall, the simultaneous application of Zn-Fe in combination with Ca was more effective in reducing of the mentioned traits than other treatments. Therefore, in order to simultaneously reduce the occurrence and severity of aril paleness, spraying with Fe4Zn6Ca4 and Fe4Zn3Ca4 is recommended in two stages of pomegranate fruit development, including the beginning of fruit set and the beginning of fruit ripening.
Pomology
M. Jalali; N. Moallemi; E. Khaleghi; S. Zivdar; M. Rahmati-Joneidabad
Abstract
IntroductionThe date palm (Phoenix dactylifera L.) tree tolerate high temperatures, drought and salinity more than other fruit crop, that is why date palm tree is named the tree of life in the desert. Date palm (Phoenix dactiylifera) is one of the fruit tree crops that is cultivated in arid region of ...
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IntroductionThe date palm (Phoenix dactylifera L.) tree tolerate high temperatures, drought and salinity more than other fruit crop, that is why date palm tree is named the tree of life in the desert. Date palm (Phoenix dactiylifera) is one of the fruit tree crops that is cultivated in arid region of Middle East and North Africa having a significant role on the economy of many countries in these regions. Fruit thinning is one of the major operation for improving the quality of dates as also for other fruit trees. Quality of dates is improved by increasing fruit weight and size and regulating date palm production by reducing the magnitude of year to year production affecting the date palm. Date palm orchard operations include all operations that are repeated annually to produce date fruit. Alternate bearing is common phenomenon in date palms. The thinning is one of the main methods that often helps to solve this problem. The main purpose of thinning is to create a suitable balance and often to increase the leaf to cluster ratio. It is creating a balance between vegetative growth and flowering and reducing the possibility of aging in the alternate bearing. Fruit thinning is one of the necessary operations that affects the growth, quality, fruit yield and regulation of the alternate bearing of the tree. The thinning process is performed manually, mechanically and chemically. Therefore, choosing a thinning method that saves time and money is necessary for date palms, especially in critical situations. The purpose of this experiment was to investigate the effects of manual and chemical thinning on the qualitative characteristics of date fruit at different stages of development for the Khadrawi cultivar. Materials and MethodsAn experiment was carried out as factorial experiment based on randomized complete block design with 3 replications at Shahid Chamran University of Ahvaz in 2022 and 2023. The Experimental factors included: hand thinning (No hand thinning, removal of 33%, removal of 25% of the total number of strands) and chemical thinning (zero, 50 and 100 mg per liter of naphthalene acetic acid). Chemical and strand thinning were done in the Hubabok stage (about 4 weeks after pollination) and the Kimri stage (12 to 13 weeks after pollination), respectively. In two consecutive years, the fruits were transferred to the plant physiology laboratory of the Department of Horticultural Sciences, Faculty of Agriculture, Shahid Chamran University of Ahvaz. The qualitative traits such as total soluble solids (%), pH, total acidity (%), taste index, antioxidant activity (%), total phenol (mg.g-1 FW), total soluble tannin (mg.g-1 FW), ascorbic acid (mg.g-1 FW), poly-galacturonase enzymes (U.g-1 FW), methyl pectin esterase (U.g-1 FW), cellulase (U.g-1 FW) and invertase (U.g-1 FW) and the percentage of reducing (%), non-reducing (%) and total sugars (%) were measured. Results and DiscussionThe results of this experiment showed that in the Tamar Stage, the interaction of hand and chemical thinning improved the qualitative characteristics of the fruit and on the characteristics of soluble total tannin, polygalactronase activity, pectin-methylesterase and reducing and total sugars, and the effect of hand thinning on total and percentage phenol and Non-reducing sugar and chemical thinning had a significant effect on ascorbic acid and cellulase enzyme. The results showed that there was upward trend in amount of total soluble solids, pH, total acidity, taste index, poly-galactronase, pectin-methyl-esterase, cellulase and invertase enzymes and the reducing and total sugars from the Kimri to Tamar stage. Also, there was downward trend in amount of total phenol, total soluble tannin content, ascorbic acid, and non-reducing sugar percentage from the Kimri stage to the Tamar. ConclusionsThe Khadrawi date variety has short strands, which results in a significant density of fruits on the strands of a cluster, which leads to large changes between fruits in most of the biochemical properties and has a negative effect on marketability. Fruit thinning is one of the most important agronomic practices in groves, as it enhances the quality characteristics of the fruit. Although hand thinning is more expensive, time-consuming, and relatively more difficult than chemical thinning, our findings showed that the quality of date fruit from the Khadrawi cultivar improved with the removal of 25% of the total number of strands and with chemical thinning using 100 mg/liter of naphthalene acetic acid. These treatments are recommended for palm growers.
Pomology
S.A. Mousavi; A. Vatankhah; A. Imani
Abstract
Introduction
Almond (Prunus dulcis L.) is one of the valuable nut trees that is cultivated in many temperate regions and Mediterranean climatic conditions for domestic consumption and export. Almond belongs to the genus Prunus, from the Rosaceae family. Identifying and introducing genotypes and cultivars ...
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Introduction
Almond (Prunus dulcis L.) is one of the valuable nut trees that is cultivated in many temperate regions and Mediterranean climatic conditions for domestic consumption and export. Almond belongs to the genus Prunus, from the Rosaceae family. Identifying and introducing genotypes and cultivars of late bloom is one of the most important goals of almond breeding programs. The correct choice of almond rootstock causes better management of the garden, compatibility with all types of soil and resistance to nematodes. Peach × almond hybrid has been the most widely used rootstock in both dry and irrigated conditions in the past years. Creating an orchard by selecting grafted genotypes on suitable rootstock for sustainable cultivation of almonds is particularly important. Cultivation of superior genotypes grafted on fruit trees has an effect on pomological characteristics, yield and quality of nuts. The requirement for the introduction and production of superior cultivars is an accurate selection between cultivars, which is possible through the identification of cultivars and their diversity. The purpose of this research is to investigate and evaluate the most important vegetative, phenological, quantitative, and qualitative characteristics of nuts and kernels in 36 promising cultivars and genotypes grafted onto GN15 rootstock, with the goal of identifying and introducing superior cultivars.
Materials and Methods
In this research, 36 promising almond cultivars and genotypes on GN15 rootstock were investigated in garden conditions in terms of various vegetative traits, nut and kernel characteristics in order to obtain suitable commercial cultivars. This research was conducted at the Badam research station in Saman region affiliated to the Center for Research and Education of Agriculture and Natural Resources of Chaharmahal and Bakhtiari province as a randomized complete block design with three replications. The cultivars and genotypes studied are presented in Table 1. Vegetative traits of tree height, canopy length, canopy width, and branch length were measured by meter in the garden, and rootstock diameter, scion diameter, and branch diameter were measured in the garden with calipers. In order to measure the nut and kernels, 100 fruits were harvested from each of the studied cultivars and genotypes at the time of fruit ripening, and their green shell was separated and dried. Measurement of traits such as length, width, diameter of nut and kernel was done by digital caliper and weight of nut and kernel was measured by digital scale with accuracy of 0.01. Coding of some traits was done based on almond descriptor (Gülcan, 1985) with some changes. The data obtained from the experiment were analyzed using SAS software (version 3.1.9). To compare the means, Duncan's multiple range test was used at the 5% probability level.
Table 1- Promising cultivars and genotypes examined in this study (based on the sent label of the scion)
Cultivar/genotype
Cultivar/genotype code
Cultivar/genotype
Cultivar/genotype code
TS-16
GA1
2-29 (D7)
GA 19
D
GA 2
100-1-1
GA 20
TS-21
GA 3
2-0-4
GA 21
TS-14
GA 4
3-1-4
GA 22
Aviz
GA 5
TS-18
GA 23
A8
GA 6
D2
GA 24
B8
GA 7
TS-30
GA 25
100-1-8-1
GA8
1306 (Tabriz genotype)
GA 26
2-3-2
GA 9
AH2 (Tabriz genotype)
GA 27
TS-11
GA 10
108 (Tabriz genotype)
GA28
( 1/16) 1-16
GA 11
Yalda
GA29
3-1-15
GA 12
Saba
GA 30
13-40
GA 13
Shamshiri (Shahrekord)
GA 31
TS1
GA 14
AY (Shahrekord)
GA 32
8-35
GA 15
Mamaei
GA 33
85
GA 16
AN2 (Shahrekord)
GA 34
35
GA 17
AN4 (Shahrekord)
GA 35
B6
GA 18
AN5 (Shahrekord)
GA 36
Results and Discussion
According to the results of analysis of variance (ANOVA), there was a statistically significant difference at the level of 1% between the attributes of tree height, canopy width, rootstock and scion diameter, branch length and diameter, and the ratio of tree height to canopy length. (P<0.01). The results of variance analysis show that there is a significant difference between the investigated nut and kernel traits in promising cultivars and genotypes grafted on GN (Table 5). These differences show the diversity in the investigated traits and it is possible to choose cultivars for different values of the same trait. Based on the average comparison results of the vegetative traits, the highest height in genotypes GA4, GA3, GA35, The highest canopy width was observed in genotypes GA5, GA17, GA3, and GA20, GA15, GA5, the highest diameter of rootstock and scion, and the highest length and diameter of one-year branches were observed in genotype GA18. The results of the comparison of the average nut and kernel characteristics show that there is a significant difference in the cultivars and genotypes investigated in this research. The results of the comparison of the average nut and kernel characteristics show that there is a significant difference in the cultivars and genotypes investigated in this research. Based on the obtained results, cultivars and genotypes of GA5, GA24, GA12, GA9 and GA1 showed relative superiority in terms of nut and kernel traits. The results of this research showed that the GA35 genotype grafted on the GN15 rootstock had the highest length, width and diameter of the nut, and the highest weight of nut and kernel. The kernel color light, the without shrinking the kernel and the highest percentage of kernel and the highest ratio of kernel weight to nut weight.
Conclusions
The results of this research showed that the examination of vegetative traits, nuts and kernels in the studied cultivars and genotypes could show the diversity between cultivars and genotypes. The results showed that the investigated cultivars and genotypes have significant differences in terms of all nut and kernel traits, which indicates the existence of diversity between the investigated cultivars and genotypes. This indicates that these cultivars and genotypes can be considered a valuable source of germplasm for breeding programs. Cultivars and genotypes with a higher kernel percentage had thinner shells, more patterns on the skin, and light to medium kernel color. Based on the results, the cultivars and genotypes GA5, GA24, GA12, GA9, and GA1 demonstrated relative superiority in terms of nut and kernel traits. The research also showed that the GA35 genotype grafted onto GN15 rootstock had the greatest nut length, width, and diameter, as well as the highest nut and kernel weight. Additionally, GA35 had light kernel color, no kernel shrinkage, the highest kernel percentage, and the highest kernel-to-nut weight ratio.
Pomology
S.M Gholami; M. Hadadinejad; H. Moradi; H. Sadeghi
Abstract
Introduction
Bud dormancy is one of the important issues in planting and cultivation of fruit trees that needs to be addressed in many trees such as orange (Citrus sinensis). Bud dormancy involves cessation of horizontal and vertical growth, lack of budbreak, and reduction in plant activity during cold ...
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Introduction
Bud dormancy is one of the important issues in planting and cultivation of fruit trees that needs to be addressed in many trees such as orange (Citrus sinensis). Bud dormancy involves cessation of horizontal and vertical growth, lack of budbreak, and reduction in plant activity during cold weather. One of the commercial orange cultivars is Tarocco blood orange which compared to older blood cultivars, is larger in size and with lower alternate bearing has higher marketability. The nursery trees of this cultivar are grafted on sour orange, citrange, and vigorous rootstock of citrumelo (a hybrid between trifoliate orange and grapefruit) (Talon et al., 2020). One of the major problems of nurserymen in spring grafting of Tarocco cultivar on vigorous citrumelo rootstock is the failure of about 50 percent of buds to break compared to other cultivars on the same rootstock and other similar rootstocks. This unwanted dormancy leads to a one-year delay in the nursery tree production process and unnecessary occupation of nursery space. Given the commercial importance of blood orange and the adverse effects of bud dormancy on yield and fruit lifetime, solutions are used to control and overcome this problem. One of the effective solutions is the application of cytokinins which can stimulate the growth of graft buds (Yadav & Saini, 2018).
Materials and Methods
This research was conducted in a citrus nursery at the University of Agricultural Sciences and Natural Resources of Sari, in late May 2022. Citrumelo seedlings were grown in 5.3 liter pots containing a loamy-silt soil mix in the nursery location. Tarocco cultivar buds were prepared from a seven-year-old mother orchard and T-budding was performed in June (during rootstock bark slipping). All hormone treatments were applied after graft union and before bending the branch using a soft brush on the graft buds. The applied treatments included hormone treatment (control, 5000 mg.l-1 benzyladenine, 1000 mg.l-1 kinetin, and 50 mg.l-1 thidiazuron) and treatment time (13, 15, and 17 days after grafting). After two months, some traits related to budbreak and growth of the grafted buds were evaluated.
Results and Discussion
The results showed that thidiazuron and benzyladenine treatments had better effects compared to kinetin treatment on spring budbreak and initial growth of Tarocco grafted buds. In a way that 50 mg.l-1 thidiazuron treatment had the highest number of sprouted buds (67.91), largest leaf area (118.04 cm2), highest number of leaves (16.50), especially when applied 13 days after grafting. Also, in leaf size related traits, leaf area indices, graft growth rate as well as chlorophyll and carotenoid content of Tarocco graft leaves were significantly affected by different hormonal treatments and application times, with 50 mg.L-1 thidiazuron being more effective than other treatments. Cytokinins can promote division and expansion of leaf cells and thereby result in increased cell numbers and improvement of different leaf parameters. Also, cytokinins regulate important physiological processes like photosynthesis. Application of these materials provides cell division especially in areas like buds and growth points and also possibly more buds may form on the spring graft by using these treatments during the grafting process which can lead to increased bud break and faster plant growth (Cook & Bahar, 2017). Increasing cytokinin levels can stimulate the photosynthesis process which results in increased food production, leaf growth and ultimately increased leaf area. On the other hand, cytokinins affect plant metabolism and can regulate production and accumulation of different growth factors. This may lead to a better balance in nutrient distribution and metabolic activities which in turn aids leaf area increase (Hodchek et al., 2023). Finally, according to the obtained results, it can be recommended to nurserymen of this cultivar to use 50 mg.L-1 thidiazuron 13 days after grafting as a practical and effective strategy for increasing spring budbreak, growth and development of Tarocco buds grafted on citrumelo.
Conclusions
In general, based on the results, the application of 50 mg.l-1 of thidiazuron 13 days after grafting can be considered a practical and effective strategy to enhance bud awakening, as well as the growth and development of Tarocco spring shoots on citronmelo. This practice is recommended for producers of seedlings of this cultivar.
Pomology
J. Samimi; Y. Selahvarzi; A. Tehranifar; N. Beikzadeh
Abstract
IntroductionPear (Pyrus communis L.) is a cold-climate fruit tree belonging to the Rosaceae family, and it is native to Western Asia and Eastern Europe. Fire blight disease is caused by the gram-negative bacterium Erwinia amylovora, and it is considered one of the most damaging and harmful diseases in ...
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IntroductionPear (Pyrus communis L.) is a cold-climate fruit tree belonging to the Rosaceae family, and it is native to Western Asia and Eastern Europe. Fire blight disease is caused by the gram-negative bacterium Erwinia amylovora, and it is considered one of the most damaging and harmful diseases in pome fruit trees in cold and temperate regions worldwide. The most sensitive plant organ in pome fruit trees to this disease is flowers. Fire blight disease has five important stages, from initial infection to the final death of the tree trunk. These five stages include blossom blight, fruit blight, leaf blight, main branches, and trunk blight, and finally, root blight. The first and most important stage of pathogenicity in fire blight disease begins in early spring under high humidity, causing the burning and death of the flower. Materials and MethodsThe Rootstock used in this experiment were Dargazi and Pyrodwarf, and the cultivars studied were Koshia and Dargazi. The experiment was conducted in two conditions, orchard and greenhouse. In the orchard, a factorial experiment was carried out in a completely randomized block design with five repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Koshia and Dargazi). In the greenhouse, a factorial experiment was carried out in a completely randomized design with three repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Dargazi and Kosha). Gardner scale was used to measure the severity of fire blight infection. In addition, the levels of sucrose, sorbitol, and pH in leaf tissue were measured. The sucrose content in the leaf tissue of Koshia/Pyrodwarf Rootstock increased from day 0 to 6 and reached its highest level (10%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Pyrodwarf base, sucrose levels increased from day 0 to 6 and reached its highest level (8%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Dargazi base, sucrose levels increased from day 0 to 6 and reached its highest level (7%) on the 6th day, then decreased to 4% on the 12th day. The sorbitol content in the leaf tissue of Koshia/Pyrodwarf base increased from day 0 to 6 and reached its highest level (2%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1.5%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Dargazi Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1%) on the 6th day, then decreased to 0.5% on the 12th day. On the other hand, the pH of the leaf tissue in the Dargazi/Pyrodwarf base remained constant at 6.2 from day 0 to 12 and increased to 7.4 on the 12th day. Results and DiscussionThe rootstock used in this experiment were Dargazi and Pyrodwarf, and the cultivars studied were Koshia and Dargazi. The experiment was conducted in two conditions, orchard and greenhouse. In the orchard, a factorial experiment was carried out in a completely randomized block design with five repetitions. The factors studied were rootstocks (Dargazi and Pyrodwarf) and cultivars (Koshia and Dargazi). In the greenhouse, a factorial experiment was carried out in a completely randomized design with three repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Dargazi and Koshia). Gardner scale was used to measure the severity of fire blight infection. In addition, the levels of sucrose, sorbitol, and pH in leaf tissue were measured. The sucrose content in the leaf tissue of Koshia/Pyrodwarf Rootstocks increased from day 0 to 6 and reached its highest level (10%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sucrose levels increased from day 0 to 6 and reached its highest level (8%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Dargazi Rootstock, sucrose levels increased from day 0 to 6 and reached its highest level (7%) on the 6th day, then decreased to 4% on the 12th day. The sorbitol content in the leaf tissue of Koshia/Pyrodwarf Rootstock increased from day 0 to 6 and reached its highest level (2%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1.5%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Dargazi Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1%) on the 6th day, then decreased to 0.5% on the 12th day. On the other hand, the pH of the leaf tissue in the Dargazi/Pyrodwarf Rootstock remained constant at 6.2 from day 0 to 12 and increased to 7.4 on the 12th day. The collected data from both orchard and greenhouse experiments were analyzed to determine the effects of Rootstock and cultivar on fire blight resistance. ConclusionThe results showed that the combination of Koshia/Dargaz had higher resistance to fire blight compared to Koshia/Pyrodwarf. Additionally, the pH and carbohydrate content in the leaf tissue of the rootstock affected the growth and proliferation of fire blight bacteria. This study demonstrated varying levels of resistance to fire blight among the studied combinations, indicating significant potential for breeding and improving pear resistance to this disease. The Dargazi cultivar exhibited very high resistance to fire blight in both orchard and greenhouse conditions. Overall, the resistance of the Dargazi rootstock contributed to the resistance of the sensitive Koshia cultivar.
Pomology
F. Azarmi-Atajan; M. H. Sayyari Zahan; A. Mirzaei
Abstract
IntroductionPhosphorus (P) is one of the most important nutritional elements of plants and it is necessary for the development of plant roots. Due to the high cost of chemical fertilizers, it is important to use cheap sources such as rock phosphate (RP) to supply P needed by plants. The efficiency of ...
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IntroductionPhosphorus (P) is one of the most important nutritional elements of plants and it is necessary for the development of plant roots. Due to the high cost of chemical fertilizers, it is important to use cheap sources such as rock phosphate (RP) to supply P needed by plants. The efficiency of RP is low and its use alone cannot supply the P required by the plant. One of the ways to increase the efficiency of RP is to use phosphate solubilizing bacteria (PSB). Considering the salinity of soil and irrigation water in many pistachio-growing areas of Iran, the use of salt-resistant PSB can increase their resistance to salt stress in addition to supplying the P required by pistachios. Materials and MethodsIn order to investigate the role of PSB in supplying the required P of pistachio seedlings under saline conditions, a factorial experiment was conducted in the form of a completely randomized design with 3 replications in greenhouse conditions. The factors included PSB at three levels [control (PSB0), Pseudomonas sp. 1 (PSB1) and Pseudomonas sp. 2 (PSB2)], RP at two levels (0 and 30 mg P from rock RP) and irrigation water salinity at three levels (0, 5 and 10 dS/m). The bacteria used in this study were able to produce ACC-deaminase, indole acetic acid and dissolve tricalcium phosphate in vitro. For inoculation, inoculum containing each bacterium with a population of 108 cells/ml was prepared in the nutrient broth medium and each pistachio seed (P. vera L. cv. Badami) was inoculated with 500 µL of bacterial inoculum. The plants were irrigated with non-saline water for four weeks and then with saline water until harvesting based on experimental treatments. During the growth period, the soil moisture of the pots was kept at about 80% of the field capacity by weight method. Finally, shoot and root sampling was performed and various characteristics such as shoot and root dry weight, chlorophyll, carotenoids, proline, soluble sugars, RWC, MSI and phosphorus as well as sodium concentrations were measured. Analysis of variance of traits was performed using SAS software and the means were compared using the LSD method with a probability level of P≤0.05. Results and DiscussionThe results showed that water salinity decreased the dry weight of shoot and root, chlorophyll a, chlorophyll b, carotenoids, relative water content (RWC) and membrane stability index (MSI) of leaf and p concentration of shoot and root of pistachio seedlings. Auxin produced by bacteria can directly increase cell division and growth or indirectly increase ACC-deaminase production. On the other hand, proline, soluble sugars and sodium were accumulated in the leaves of seedlings with increasing water salinity. According to the results, although the use of RP alone did not show significant effect on the studied indicators, its simultaneous use with PSB had the greatest role in improving the growth of pistachio seedlings, especially in saline conditions. The highest amount of dry weight of shoot (1.89 g.plant) and root (1.59 g.plant), chlorophyll b (1.30 mg/g fresh weight), carotenoids (1.35 mg/g fresh weight), soluble sugars (59.1 mg/g fresh weight), proline (36.7 mg.g-1 fresh weight), leaf RWC (91 %), leaf MSI (84%) and the P concentration of shoot (0.39 %) and root (0.35 %) was obtained from the simultaneous application of RP and PSB (especially PSB2) in non-saline conditions. The PSB increase soil P availability by reducing of soil pH by release of protons and organic acids and mineralization by production of acid phosphatases. Bacteria, in addition to increasing soil P availability, improve phosphorus uptake and chlorophyll content in plants by affecting root morphology and its development in soil. On the other hand, inoculation with PSB (both separately and together with rock phosphate) reduced sodium accumulation in the aerial parts and roots of pistachio seedlings. ConclusionUnlike pistachio trees, the tolerance of pistachio seedlings to salt stress is low. According to the results, the salinity symptoms were visible in the pistachio seedling leaves at the water salinity level of 10 dS/m, which caused the drying of the lower leaves and the burning of the edges of the young leaves. On the other hand, although the application of RP alone did not have significant effect on increasing the tolerance of plants to salt stress, the simultaneous use of RP with PSB increased growth, the accumulation of proline and soluble sugars, the concentration of chlorophyll and carotenoids, the amount of RWC and MSI and P concentration of pistachio seedlings, especially in saline conditions. Therefore, the use of PSB can help the growth and establishment of pistachio seedlings under salinity stress conditions and increase the efficiency of RP and supply P needed by the seedlings.
Pomology
A. Heydari; S. Daghighi; F. Azarmi-Atajan
Abstract
Introduction Pistachio (Pistacia vera L.) is an important crop in Iran our country and has a unique position in export goods. The amount of pistachio production in Iran has decreased by 50% compared to 2017. The low yield of pistachios per unit area is due to the management problems of orchards, ...
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Introduction Pistachio (Pistacia vera L.) is an important crop in Iran our country and has a unique position in export goods. The amount of pistachio production in Iran has decreased by 50% compared to 2017. The low yield of pistachios per unit area is due to the management problems of orchards, and among these, nutrition and fertilizer management is of special importance. Among the nutrients that are important in pistachio nutrition, especially when the brain is full, are nitrogen and potassium. Humic acid can also improve physical, chemical and biological soil properties and stimulate growth via its effects on plant metabolism.The aim of this study was to investigate the effect of application of some nitrogen fertilizers with different levels of potassium sulfate and humic acid on growth, yield and photosynthetic pigments of pistachio Badami Sefid-e-Mahvalat variety. Materials and Methods This research was conducted as a factorial experiment based on a randomized complete block design with three replications at the Mahvalat during 2019-2020. The first factor consisted of nitrogen fertilizers at 4 levels (control, urea, ammonium sulfate and ammonium nitrate). The second factor was potassium sulfate fertilizer at 2 levels of zero and 250 g per tree and the third factor was humic acid fertilizer at 2 levels of zero and 45 g per tree which as a manure pits after the formation of the cluster and at the same time with the growth of the bony shell in the shade of the tree where the capillary roots are active. At the end of the experiment, morphophysiological traits were measured and recorded. In each tree, three branches were selected in different directions and the length of the current branch was measured in meters using centimeters. The diameter of the middle of the branch was measured with a caliper. From the collected clusters, 100 fruits were randomly selected, and the number of indehiscence fruits and the number of blank fruits were counted and finally expressed as a percentage. Measurements of chlorophyll a and b, total chlorophyll and carotenoids were determined using Arnon method. The experimental data was analyzed by SAS software and the significant differences among the treatment were tested by LSD test. Results and DiscussionThe results of analysis of variance of data in two years of experiment showed that experimental treatments had a significant effect on pistachio growth and yield. The results of the first year showed that the combined treatment of urea and 250 g of potassium sulfate and 45 g of humic acid had the highest diameter and branch length, indehiscence percentage, chlorophyll a, b and total and the lowest pistachio blank percentage. The highest yield in the first year was obtained from the combined use of ammonium sulfate, 250 g of potassium sulfate and 45 g of humic acid. Combined application of ammonium nitrate and 250 g of potassium sulfate and 45 g of humic acid resulted in the highest diameter and branch length in the second year of the experiment. The highest indehiscence percentage and carotenoids and the lowest amount of pistachio blank percentage in the second year were obtained from the combined treatment of ammonium sulfate, 250 g of potassium sulfate and 45 g of humic acid. Most chlorophyll a, b and total were obtained from combined consumption of urea, 250 g of potassium sulfate and 45 g of humic acid. The highest yield of the second year was obtained due to urea consumption, 250 g of potassium sulfate and 45 g of humic acid. Nitrogen is a component of amino acids, proteins, nucleic acids and enzymes and plays a major role in plant physiology, vegetative growth, chlorophyll formation and fruit and fruit production. Potassium is also one of the elements required by the plant that plays an important role in photosynthesis and transport of carbohydrates. The organic acids in humic acid cause the chelating of many nutrients and increase their availability to the plant. By using these substances and its positive and stimulating effects on plant growth and increasing root growth and its absorption power, nutrient uptake, yield is increased.
Pomology
S. Khodaei; E. Ganji Moghadam; M. Zamanipour
Abstract
IntroductionSince Iran is one of the arid and semi-arid regions of the world and due to the great importance of water in agriculture, it is very important to conduct research to improve drought stress in order to produce more quality products. In this regard, this study was conducted to investigate the ...
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IntroductionSince Iran is one of the arid and semi-arid regions of the world and due to the great importance of water in agriculture, it is very important to conduct research to improve drought stress in order to produce more quality products. In this regard, this study was conducted to investigate the effect of mycorrhiza species on some morphological and physiological characteristics of peach seedlings under drought stress. Arbuscular mycorrhizal fungi coexist with the roots of various plants and have a broad effect on their growth. These fungus are effective in the initial establishment of the plant under drought conditions. Arbuscular mycorrhizal fungi increases plant resistance to dehydration by increasing growth and uptake of nutrients, especially phosphorus. Matherials and MethodsIn order to investigate the effect of three species of Arbuscular mycorrhizal fungi on some vegetative characteristics and phosphorus absorption of peach seedlings under drought stress conditions, a factorial experiment was conducted based on a randomized complete block design with four replications. The experimental factors included: drought stress at four levels (100, 80, 60 and 40 percent of field capacity) and the second factor application of mycorrhizal fungus at four levels: application of three species of mycorrhiza fungi and three species of fungi, each in three concentration (75, 100, 125 g in a pot) with chemical fertilizer (100 g triple super phosphate for each pot) and fertilizer (without mycorrhiza) and control (without fertilizer and mycorrhiza). The measurements were comprised root traits, stem diameter, vegetative growth of branches, leaf area index, vegetation index, relative leaf water content, chlorophyll fluorescence, leaf electrolyte leakage, leaf phosphorus and colonization root percent. Results and DiscussionResult showed that application of mycorrhizal fungi seems to be effective in reducing the effects of dehydration stress. The use of these fungi had a positive effect on reducing leaf electrolyte leakage under severe dehydration. According to the results obtained in this experiment, the highest efficiency in drought stress conditions was observed in G. mosseae and G. intraradices. Under drought stress conditions, the lowest values of root volume, greenness index, chlorophyll fluorescence, leaf electrolyte leakage, root colonization and leaf phosphorus content were observed. With increasing of drought stress, all of the mentioned traits reduced and mycorrhiza fungi had a positive significant effect on all studied traits. In this study, it was found that with increasing stress intensity, the traits were negatively affected and led to irreparable damage to the product. Therefore, it is expected that by preventing or minimizing the effects of stress, an effective step was taken to increase performance. The significant decrease in root colonization with increasing stress is probably due to the decrease in the growth of hyphae. The most important step after spore germination is the growth of hyphae resulting from germination, which plays an essential role in root colonization. Apparently, hyphae growth is more affected by osmotic potential than spore growth. The results obtained from this research showed that the roots of peach seedlings have significant symbiosis potential with arbuscular mycorrhizal fungi (Peymaneh & Zarei, 2013). According to Miyashita et al. (2005) Leaf photosynthesis activity can be used as a useful tool for classification of drought tolerant plants. Sajjadinia et al. (2010) regarding the relative water content and photosynthesis of several pistachio cultivars reported high correlation and high diversity in different stages and cultivars and stated that the decrease in relative water content strongly reduces transpiration, stomatal conductance and photosynthesis, which our results are consistent. With the escalation of tension, the greenness index also decreased; So that in the conditions of severe stress (40% of crop capacity), the amount of greenness index reached the lowest value. In the conditions of severe stress due to interruption of continuous irrigation, the plants entered from the stage of mild stress to the stage of severe dry stress, which seems that under these conditions, the decrease in the concentration of chlorophyll, in addition to the decrease in the amount of synthesis, is caused by the decomposition of chlorophyll due to the increase in the amount chlorophyllase, peroxidase and phenolic compounds. According to Schutz and Fangmier (2001), the decrease in the amount of chlorophyll in stress conditions is related to the increase in the production of oxygen radicals in the cell. These free radicals cause peroxidation and as a result the decomposition of this pigment. The greenness index is considered one of the most important growth parameters, which is reduced by drought stress conditions, and the results indicate that the treatment of mycorrhizal fungi in all three types of inoculated mushrooms has improved the greenness index and the adverse effects It has removed the drought stress to a great extent (Figure 6), which can be attributed to the improvement of water and food absorption by mycorrhizal roots (Larsson et al., 2008). Conclusion In general, this study showed that the best treatment related to the mycorrizha fungi was mosseae, which had the most effect on reducing the negative effects of stress
Pomology
Z. Rohi Vishekaii; A. Soleimani; M. Ghasemnejad; A. Hasani
Abstract
Introduction Olive tree, with a thousand years of cultivation history, is one of the most important horticultural crops in Iran and has always played an important economical role for orchardists. In olive orchards traits such as an increased formation of incomplete flowers, low yield of fruits and ...
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Introduction Olive tree, with a thousand years of cultivation history, is one of the most important horticultural crops in Iran and has always played an important economical role for orchardists. In olive orchards traits such as an increased formation of incomplete flowers, low yield of fruits and oil are often found as major problems. It should be noted that these traits are affected by numerous environmental and management factors from which the nutrition status is one of the most important ones. Proper nutrition plays an important role in both olive fruit and oil yield. There is a wide range of fertilizer compounds with different formulas and efficiencies available in the world market, among which nano-products are becoming increasingly popular. However, there is limited information on their efficacy in different plant species. Materials and MethodsIn order to evaluate the impact of fertilizers on olive cultivation, a research was conducted during two successive years from 2019 to 2020 in a commercial orchard on 15 year old olive tree cv. ‘Zard’, in Manjil city of Guilan province. Foliar application included five treatments using two types of fertilizers; nano (nano-chelated nitrogen and potassium: nano-NK) and chemical fertilizers (urea and potassium nitrate; NK). Treatments involved application of two concentrations from each fertilizers sources; 1.02g and 0.81g (nano-N1K1 and N1K1), 1.36 g and 1.08 g (nano-N2K2 and N2K2) of pure nitrogen and potassium, respectively. Foliar application was conducted in four stages bud-swelling, before blooming, pit hardening and shortly after harvest of table olive. Spraying with water was considered as the control. The nano-chelated fertilizers were obtained from Khazra Company, Teheran, Iran (http://en.khazra.ir). Spraying with water was considered as control. The experiment was performed in a randomized block design with three replications. The measurement of leaf nutrient status and its chlorophyll and carbohydrate contents were carried out at two times each growing season; in August (during pit hardening stage) and October (shortly after the harvest of table olive). At the green ripening stage, fruits were collected and weighted to determine fruit yield. At the end of the experiment quantity and quality traits of oil were measured. Results and Discussion The results showed that the trees under N2K2 treatment had the highest yield. In terms of mineral content, both forms of fertilizers increased the concentration of nitrogen and potassium leaf elements compared to the control trees. Chlorophyll content was affected by nano-N1K1 foliar application and carbohydrate content was affected by nano-N1K1 in the pit hardening stage and nano-N2K2 in shortly after the harvest of table olive. Nano-N1K1 treatment with the lower crop load not only increased oil content but also improved quality characteristics of olive oil (free fatty acids, peroxide value, specific ultraviolet absorbance K232, K270 and contents of pigments), total phenol content, antioxidant capacity and fatty acid composition. Generally, the results showed that olive trees responded well to fertilizer feeding. These trees produced better crop and higher quality oil in comparison with control trees. According to the results, fruit yield is better under urea and potassium nitrate treatment, and the quality of olive oil is more stable after nano-chelated nitrogen and potassium foliar application. It seems that the reason for the high amount of fruit yield with N2K2 in comparison to the slow-release property of nano-fertilizers is that using nitrogen and potassium in the form of ordinary chemical fertilizer regulates the biosynthesis, conversion and rapid translocation of assimilates and mineral elements into reproductive structures, which resulted in soaring yield. We assumed that nano-N1K1 foliar spray in the pit hardening stage and shortly after the fruit harvest for table olive might export the assimilation into the fruit to fulfill cell metabolism requirements for oil synthesis. Conclusion The current findings indicated that two of four treatments, i.e. nano-N1K1 and N2K2, could be more effective on olive trees in terms of general fruit and oil attributes. It was remarkable that nano treatment with a lower concentration could provide adequate beneficial effects on quality characteristics of olive oil and is in line with good management strategies regarding the preservation of the environment. To the best of our knowledge, the current work is the first report considering the application of nano-chelated nitrogen and potassium and their is use as a foliar application on olive trees. Additional studies would be necessary to further optimize the concentration and timing of the applications with these new formulations.
Pomology
A. Bonyanpour
Abstract
IntroductionPomegranate is a native fruit tree to Iran and has the best growth and performance in subtropical climate conditions. In recent years, due to environmental stresses conditions such as high temperature, high light intensity and low irrigation water a large number of orchards have faced to ...
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IntroductionPomegranate is a native fruit tree to Iran and has the best growth and performance in subtropical climate conditions. In recent years, due to environmental stresses conditions such as high temperature, high light intensity and low irrigation water a large number of orchards have faced to physiological problems such as fruit cracking, sunburn and a decrease in fruit quality. The high temperature along with high evaporation and transpiration can be considered as the main cause of these abnormalities, which causes disturbances in the process of plant metabolism and finally causes physiological disorders. Sunburn of the fruit is caused by high temperature and high sunlight intensity and has a negative effect on all the quality characteristics of the pomegranate fruit. Using net shade is one of the recommended ways to reduce the impact of climate change. Application of net shading in areas with high radiation levels has led to a decrease in the intensity of light radiation received by the canopy of the trees, which causes a decrease in the temperature of the leaf surface, and decrease the level of evaporation and transpiration in the trees. Materials and MethodsThis research was conducted during 2019-2020 for 2 years in a private orchard in the Kohmar area of Kazeron city of Iran. ́Rabab̕ pomegranate trees that were planted at a distance of 5 x 5 m and 15 years old were used. In this research, the effect of different types of net shading was investigated. The experiment was conducted as a randomized complete block design with 9 treatments and three replications in two years. The experimental treatments included the use of net shading in white and green colors with two different shading (30% and 50%) and two implementation methods (on the base and on the canopy of the tree) which were compared with control trees (without cover). During the growing season, measurements were made in relation to leaf temperature, sunlight intensity, soil moisture, relative water content of leaves, fresh and dry matter of leaves, and prolin content, and at the time of harvest, the percentage of sunburn, cracking and aril paleness of the fruit, thickness of fruit peel and anthocyanin content of fruit juice in all treatments were measured. Results and DiscusionsThe use of net shading increased the quantitative and qualitative characteristics of pomegranate fruits. The results of this research showed that the use of white and green nets 50% and green net 30% on the base had the best results. By using the appropriate type of net shading, the temperature of the pomegranate tree was reduced by about 6 degrees Celsius. Net shading also reduced the light intensity by at least 50%; the reduction of light intensity in green nets was more than in white nets.The highest relative water content was 85% in the green net shade (50% with base) treatment. Net shading significantly increased the water content of the leaves compared to the control.The use of net shading significantly reduced the percentage of sunburn on fruits compared to the control. Sunburn was about 14% in the control treatment and less than 5% in the net shading treatments. Net shading reduced the percentage of fruit cracking from 15 percent in the control treatment to about 7 percent in all shading treatments. ConclusionThe use of net shading as a cover for pomegranate trees reduces the temperature of the canopy of the plant by reducing the radiation of the sun, and by better maintaining the moisture of the soil of the pomegranate tree. It reduces the heat and drought stress condition and has a positive effect on the quantity and quality of the fruit produced. Among the treatments used, the use 3 types of net including 50% white nets on the base, and 30% and 50% green nets on the base had the best results. These treatments better than others in terms of shading percentage, temperature reduction, and improving the quantity and quality of pomegranate fruits . Net shading should be installed when the fruits are about 5 to 7 cm in diameter and will remain on the tree until mid-September. This type of tree shading did not leave any side effects on the quantity and quality of the fruits.
Pomology
E. Khaleghi; M. Zamani Dehbari; N. Moallemi
Abstract
IntroductionCitrus fruits are one of the most commercial fruit products in the world, whose growth and production are affected by abiotic stresses. Drought stress is one of the most important abiotic stresses that affects all the vital processes of the plant. One of the ways to moderate the negative ...
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IntroductionCitrus fruits are one of the most commercial fruit products in the world, whose growth and production are affected by abiotic stresses. Drought stress is one of the most important abiotic stresses that affects all the vital processes of the plant. One of the ways to moderate the negative effects of drought stress is the use of polyamines. Polyamines are a group of biochemical compounds that are used as one of the most effective compounds to resist environmental stresses. Polyamines have a wide role in various plant growth processes, such that they play a significant role in modulating various types of biotic and abiotic stresses. Studies have shown that application of putrescine increases the fresh and dry weight of the shoot and root parts, leaf relative water content, photosynthetic pigments, leaf surface, and photosynthesis in plants under drought stress. Materials and MethodsThis study was conducted to investigate the effect of different levels of putrescine (0, 0.5, 1 and 2 mM) and different levels of irrigation (100, 75 and 50% of evotranspiration potential) on morpho-physical traits of lime seedlings as a factorial experiment based on randomized complete block design with 3 replications.Two-year-old lime seedlings were obtained from a commercial nursery located in Dezful city (approved by the Khuzestan Agricultural Jihad Organization). Then, they were located in 15-kilogram pots and kept for 2 months in the greenhouse to adapting to the environmental conditions. In order to apply the irrigation regime, 4 pots were considered as reference plants and the amount of irrigation water was determined by weighing these pots. First, the weight of reference pots was calculated in field capacity mode. Then, after 7 days, the pots were weighed again and the difference between the primary and secondary weights was considered as the amount of irrigation water of 100% plant evaporation and transpiration, and according to that, 75% irrigation and 50% evaporation and transpiration potential were applied. The first foliar spraying with putrescine was done at first of March in Field capacity (foliar spraying was done once every month for 4 months from March to June). At the end of the experiment, the fresh and dry weight of root and shoot, number of leaves, relative water content, leaf water potential, photosynthesis, transpiration, stomatal conductance, were measured. Statistical data analysis was done using MSTATC software and, Duncan's multi-range test was used to mean comparation at the 5% probability level. Results and DiscussionResults showed that the rate of photosynthesis, stomatal conductance, relative water content of leaves, fresh and dry weight of aerial part and root decreased by reducing the amount of irrigation from 100 to 75 and 50%, of ETcrop. The reduction of growth parameters under drought stress can be due to the closing of the stomata and the reduction of carbon dioxide emission into the leaves, which can lead to lower levels of chlorophyll and photosynthesis, induction of oxidative stress, and finally less growth in plants. It has also been stated that the decrease in growth caused by drought stress in the initial stages of the stress can be due to the decrease in cell growth and development due to the decrease in turgor pressure and the decrease in the intensity of photosynthesis due to the closing of stomata. Also, the results showed that foliar spraying with 2 mM putrescine increased photosynthesis, stomatal conductance, relative water content of leaves, wet and dry weight of aerial parts and roots at all irrigation levels. The researchers believed that the increase in growth parameters, relative water content and photosynthetic pigments with putrescine foliar spraying can be related to the antioxidant properties of putrescine and its osmolality role in dry conditions. Other researches have shown that putrescine may modulate certain ion channels and increase the permeability of the membrane to calcium and cause a decrease in the entry of potassium into the membrane, which causes a decrease in the exit of water from the cell. Also, putrescine may increase leaf water potential and leaf content through osmotic regulation of the plant by increasing proline. ConclusionIn general, the results showed that foliar spraying of putrescine, especially at 2 mM concentration has the greatest effect on increasing growth parameters, including fresh and dry weight of shoots and roots, leaf area, increasing the relative water content, leaf water potential and Gas exchanges and reducing the amount of ion leakage under drought stress conditions.
Pomology
N. Zeinoldini; H.R. Karimi; F. Nazoori; S. R. Sahhafi
Abstract
Introduction
Pistachio is one of the most important horticultural crops in Iran. Most pistachio orchards are located in arid and semi-arid regions of Iran, which have a lack of irrigation water. Drought stress is considered as one of the most important limiting factors for the production of plants in ...
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Introduction
Pistachio is one of the most important horticultural crops in Iran. Most pistachio orchards are located in arid and semi-arid regions of Iran, which have a lack of irrigation water. Drought stress is considered as one of the most important limiting factors for the production of plants in dry areas. Pistachio (P. vera L.) is one of the drought-resistant fruit trees due to its deep roots, but it has been reported that water stress reduces the yield and dry quality of this product. The degree of resistance to drought stress in pistachios depends on the type of rootstock, so the evaluation of pistachio species from the point of view of the rootstock is important.
Material and Methods
In order to evaluate the resistance of four pistachio rootstocks to drought stress, a factorial experiment in a completely randomized design with two drought factors at three levels (3, 6 and 9 days irrigation intervals) and a rootstock at four levels, 'Badami- e- Riz-e-Zarand', 'Ghazvini', Eurycarpa (Pistacia euricarpa), and an interspecific hybrid (P. vera × P. terebinthus) with three replications were performed under greenhouse conditions. Hybrid rootstocks produce in a breeding program using hybridization of P. vera and P. terebinthus. At the end of the experiment, the growth parameters including the number of leaves, leaf area, stem height, as well as stem diameter at a height of one centimeter above the soil surface, leaf fresh and dry weight, shoot fresh and dry weight, and root fresh and dry weight, as well as physiological and biochemical parameters including chlorophyll fluorescence (FV/FM), SPAD index, PI, Cha, Chb, total chlorophyll and carotenoids, RWC, proline, soluble carbohydrates, and phenolic compounds and concentrations of Calcium, Magnesium, Potassium and Iron elements in leaves were measured.
Results and Discussion
The results showed that drought stress reduced growth and physiological indices so that the lowest reduction in shoot dry weight was related to the hybrid rootstock and the highest reduction was related to 'Ghazvini'. It has been reported that the height and diameter of the stem of pistachio seedlings decrease significantly with the increase in irrigation period. This decrease can be attributed to the reduction of the cell turgor pressure under stress. In response to drought stress, the content of proline and soluble carbohydrates in the leaves of the studied rootstock increased. The results of this study are in line of other studies on pistachio. The highest content of proline and the lowest content of soluble carbohydrates were observed in 'Badami- e- Riz-e-Zarand’. The highest content of soluble carbohydrates belonged to Eurycarpa and hybrid rootstocks. The reason for the increase of soluble carbohydrates in the present study can be due to the decrease in the amount of photosynthesis. Drought stress exerted an influence on the nutrient concentrations within both shoots and roots, leading to an increase in potassium content. The highest concentrations of potassium in shoots and roots were noted in the Eurycarpa and hybrid rootstocks, respectively. This elevation in potassium concentration in both roots and shoots could be attributed to active absorption of this element. Plants enhance potassium absorption by expending energy to sustain stomatal conductance, cell turgor pressure, and osmotic regulation.
Conclusion
Drought stress is considered one of the most important environmental stresses, the first effects of which appear in plants in the form of reduced growth and disturbance in physiological parameters. Based on the present study, most of the measured parameters were subjected to drought treatment and the investigated rootstocks showed different reactions, so that hybrid and Eurycarpa rootstocks were less affected by drought stress than other rootstocks. According to the results of the present study, it can be postulated that Eurycarpa and hybrid rootstocks have a high potential for drought resistance.
Pomology
M. Fattahi; Sh. Pourmoghadam
Abstract
Introduction
Almond (Prunus amygdalus) is considered to be able to tolerate drought stress fairly well during all stages of growth. Water shortages are very frequent in many countries, and, together with the rising demand for the industry, the growth of the human population, climate change and ...
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Introduction
Almond (Prunus amygdalus) is considered to be able to tolerate drought stress fairly well during all stages of growth. Water shortages are very frequent in many countries, and, together with the rising demand for the industry, the growth of the human population, climate change and specifically the trend towards irrigated agriculture, have led to widespread problems of water scarcity in most countries. Plant responses to water deprivation are usually monitored through selected morphological and physiological parameters which have been proven to be good indicators of drought in different studies. Chlorophyll a (Chl a) fluorescence, produced by the Chl a molecule after excitation by light, is a non-invasive and rapid biomarker for the assessment of stress (microbial and environmental) effects on PSII, as well as its structure and function. Fluorescence induction patterns and derived indices have been used as empirical diagnostic tools in stress physiology. The aim of this study was to investigate the effect of water stress on chlorophyll fluorescence parameters in two almond genotypes. It is known that the kinetics of fluorescence transients are polyphasic when plotted on a logarithmic time scale labeled as OJIP. This curve rises from an initial low-value F0 (minimal fluorescence) to FJ (fluorescence value at 2 ms) and FI (fluorescence value at about 20–30 ms) and a peak of fluorescence FP (maximal fluorescence or Fm).
Materials and Methods
The Experiment was carried out under a completely randomized design with split arrangement having three replications. Chlorophyll and carotenoid contents were determined by the method of Lichtenthaler (1986). Fresh leaves (1 g) were triturated in 80% acetone. The absorbance of the extracts was measured at 645, 663, and 470 nm using a spectrophotometer. Chlorophyll fluorescence was measured 40 days after the start of drought treatment. Full expanded leaves were selected from each plant for measurements. They were measured with a portable photosynthetic efficiency analyzer model (Hansatech, United Kingdom). Calculations were made with computer-assisted analysis using the SPSS 25 software.
Results and Discussion
The results showed that the maximum total fresh and dry mass was recorded in the Mamaei cultivar. The drought stress caused a significant reduction in a, b, total chlorophyll and carotenoids in Rabie (R) as well as Mamaei (M) cultivars but in general, M plants had higher content of pigments in comparison with R plants under drought stress. In both of cultivars, the potential efficiency of PSII photochemistry (Fv/Fm) was reduced with an increasing drought intensity. The reduction of Fv/Fm was accompanied by a decline in Fv and Fm. The VJ, relative variable fluorescence at J step (2 ms), was increased with increase in drought levels. Plants response to drought depends on PSII ability to respond to this stress. It has been reported that water limitation reduces the quantum yield of PSII electron transport, which in turn decreases the amount of light energy reaching the reaction centers. PSII plays a pivotal role in mediating oxygen evolution activity. In our study, we observed an interaction between cultivar and drought treatment, particularly evident in parameters such as Fm, Fv, Fv/Fm, and PI. Additionally, our findings revealed a robust correlation between the Pi index and total chlorophyll content (0.647), as well as the fresh (0.685) and dry (0.695) weight of plants. Furthermore, our results indicate that drought stress significantly impairs the growth of cultivars grafted on GN15 rootstock. This may be the outcome of the inhibition of water shortage on the photosynthetic apparatus. The results discovered that carotenoids were higher in M cultivar than R cultivar, carotenoids protect the photosynthetic apparatus from photooxidative damage. Protection is afforded by quenching of the triplet state of chlorophyll, thereby preventing the formation of harmful oxidative species. We also found the performance index is the parameter that better reflects the responses of the studied cultivars to progressive drought stress.
Conclusion
We applied chlorophyll fluorescence as a biomarker to assess the growth response and PSII behavior and performance of two almond cultivars to different drought levels. In conclusion, Mamaei was less affected by drought stress in terms of total Chl, Fv/Fm, PI, and total fresh and dry weight followed by Rabie. Differential responses among cultivars under drought stress treatments were observed regarding their capacity to induce PSII activity. Parameters derived from the JIP test proved effective in characterizing the degree of response to drought stress, with PI serving as a particularly responsive multi-parametric expression.
Pomology
N. Soukht saraei; F. Varasteh; M. Alizadeh
Abstract
Introduction
In recent years, the use of organic acids has increased due to their role in the quantitative and qualitative yield and resistance to environmental stresses. Ascorbic acid (vitamin C) is one of the important antioxidants and plays a role as the primary substrate in cyclic pathways to remove ...
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Introduction
In recent years, the use of organic acids has increased due to their role in the quantitative and qualitative yield and resistance to environmental stresses. Ascorbic acid (vitamin C) is one of the important antioxidants and plays a role as the primary substrate in cyclic pathways to remove toxicity and neutralize superoxide and single oxygen radicals. Ascorbate is also involved in the regulation of cell division and photosynthesis and has nutritional value for humans and is probably important for the tolerance of plants against photo-oxidative stress. Oxalic acid is a metabolic end product in plants that has many physiological functions, the main ones is the induction of resistance to disease and environmental stress by increasing the activity of enzymes involved in resistance and secondary metabolites such as phenol, flavonoid, etc. Considering the importance of the physiological traits of the plant in the production of quantitative and qualitative yield of strawberry and on the other hand, the lack of sufficient information about the effect of external application of ascorbic acid and oxalic acid on the physiological traits of the plant, the present research work aimed to investigate some physiological and qualitative traits of strawberry leaves and fruits affected by foliar spraying of ascorbic acid and oxalic acid.
Materials and Methods
The experiment was conducted based on randomized complete block design (RCBD) with three replications in Darkalate village of Ramiyan city of Golestan province to investigate some physiological responses of strawberry cv. Camarosa to the foliar application of organic acids. The experimental treatments consisted of three levels: non-spraying as control, spraying with 1 mM ascorbic acid and 1 mM oxalic acid, which was performed in three stages (from end flowering stage to the green fruit stage) at 6 days intervals. Finally, three plants were selected from each experimental unit and leaf samples were taken and transferred to the laboratory to measure physiological traits i.e. leaf area, fresh and dry weights, total chlorophylls, chlorophyll a and chlorophyll b, total carotenoids, total sugars, total phenols and flavonoids. Also, when at least 75 percent of the fruit surface turned red, the fruits were harvested from each plot separately and immediately transferred to the Plant Physiology Laboratory of Gorgan University of Agricultural Sciences and Natural Resources. The physicochemical traits of strawberry fruits including total soluble solids (TSS), titratable acidity (TA), flavor index, vitamin C, total phenol, flavonoid, antioxidant activity, total anthocyanins were measured. Analysis of data were performed using SAS 9.2 statistical software and comparison of mean data were undertaken based on LSD statistical test.
Results and discussion
The results showed that the foliar application of ascorbic acid and organic acid had a significant effect on the leaf area, fresh and dry weights, total chlorophylls, chlorophyll a, chlorophyll b, carotenoids, total sugars, phenols and flavonoids. The highest mean leaf area (314.08 cm2), leaf fresh and dry weights (1.78 and 0.56 grams, respectively), chlorophyll a (0.43 mg/g), total carotenoids (0.29 mg/g), total sugars (1.43 µg/g), total phenols (0.70 mg/g) and flavonoids (0.19 mg/g) were observed in the application of oxalic acid. The control had the lowest mean in all studied traits (except carotenoids). The application of both ascorbic acid and oxalic acid resulted in an increase in photosynthetic pigments, elevating the total chlorophyll content by an average of 22% compared to the control group. Additionally, foliar spraying with ascorbic and oxalic acid led to higher levels of total soluble solids, increased antioxidant activity, and enhanced total flavonoid content in the fruit compared to the control group.Moreover, fruits harvested from plants treated with oxalic acid before harvest exhibited higher levels of total anthocyanin and phenol compared to fruits from plants treated with ascorbic acid before harvest and the control group. Fruits of plants treated with ascorbic acid compared to plants treated with oxalic acid had lower vitamin C and titratable acidity and higher flavor index. The physiological influence of oxalic acid was more superior than that of ascorbic acid and had higher positive effects in the studied traits were recorded. However, since ascorbate is one of the precursors of oxalic acid biosynthesis. Therefore, the changes caused by oxalic acid are indirectly influenced by ascorbic acid. Ascorbic acid acts as a cofactor in photosynthetic reactions and prevents the destruction of chlorophylls and carotenoids due to its antioxidant property, and by interfering in cell division and increasing the surface area of leaves; it increases photosynthesis and the production of carbohydrates. In general, according to the results, it was found that the application of ascorbic acid and oxalic acid improved the quality characteristics and the content of health related compounds of Camarosa strawberry fruit by increasing photosynthetic pigments and biomass.
Pomology
M. Nezami; M.R. Fatahi Moghadam; A. Ebadi; Z. Zamani
Abstract
IntroductionStrawberry is known as one of the most important temperate small fruits which is cultivated in the field, greenhouse and high tunnels in the most regions of the world. The role of gibberellin and auxin in increasing fruit size of strawberries have been reported. One of the major problems ...
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IntroductionStrawberry is known as one of the most important temperate small fruits which is cultivated in the field, greenhouse and high tunnels in the most regions of the world. The role of gibberellin and auxin in increasing fruit size of strawberries have been reported. One of the major problems of strawberry production in greenhouse is the fruits malformation which has reduced the market value of the fruit. Gibberellin and auxin have been different effects in vegetative and reproductive of growth stages. The purpose of this research was to improve the vegetative and reproductive indices of the fruit and to control the malformation problem by stimulating the development of seeds on the fruit and stimulating the growth of the fruit receptacle by gibberellin GA3. Materials and MethodsExperiments were conducted in a commercial greenhouse in Karaj, Hashtgerd New City, Phase 7 during 2017-2019. Two separate experiments (spraying hormones on whole plant or immersing individual fruitlets on hormone solution) were designed and implemented in a commercial greenhouse unit. In the first experiment: GA3 was at concentrations of 50, 100 and 150 ppm and IBA at concentrations of 20, 40 and 60 ppm in growth stages of 60 and 65 according to BBCH worldwide model. In the second experiment, fruits were immersed in NAA with concentrations of 20, 40 and 60 ppm and GA3 with concentrations of 25, 50 and 100 ppm at fruit growth stages 70 and 73 according to BBCH procedure. After reaching the red stage, the fruits were manually harvested and transferred to the laboratories for additional tests. Vegetative and reproductive traits were evaluated including leaf area, number of leaves, crown circumference, plant height, number of flowers and fruit dimensions. Fruit biochemical characteristics include: total soluble solids, titratable acid content of fruit, anthocyanin and antioxidant capacity, total phenolics, catalase and superoxide dismutase enzymes activities and content of vitamin C were evaluated. The experiments were designed and implemented in the frame of a randomized complete block design. The data were analyzed by SAS ver.9.4 and SPSS ver. 22 software, the mean data were compared based on Duncan's multi-range test, and the graphs were drawn by Excel 2013 software. Results and DiscussionFoliar spraying with gibberellin had a significant effect on several characteristics, including leaf area, crown circumference, number of flowers, and plant height at the 1% level of significance. However, it did not yield a significant impact on the attribute of leaf number. The increase in vegetative growth could be due to the synthesis of more amino acids in the stimulation of gibberellin treatment. Gibberellin treatments increased the vegetative growth of the plant and increased the number of flowers, but their growth was stopped after fruit formation and no fruits were formed in gibberellin spraying. This can be due to the existence of an antagonistic relationship between vegetative parts and fruit developments. Auxin hormone treatments had a significant effect on increasing fruit size and reducing the percentage of malformed fruits. GA3 at concentration of 50 ppm improved plant vegetative characteristics such as: plant leaf area, plant crown circumference, plant height and number of flowers, while IBA reduced fruit deformity by 40% and also increased the amount of total soluble solids, the titratable acid content of the fruit and the antioxidant content of the fruit. In general, gibberellin at a concentration of 50 ppm in order to increase plant vegetative indices and auxin at a concentration of 60 ppm were statistically effective. In second experiment, it seems that three levels of gibberellin treatment have increased all traits related to fruit compared to auxin and control. GA3 at a concentration of 100 ppm, causing an increase in fruit size, fruit weight and the biochemical properties of the fruit and the deformity decreased by 37/5% while NAA at a concentration of 60 ppm increased the amount of fruit anthocyanin as well as total fruit phenolics and vitamin C content. ConclusionIn the first experiment, gibberellin foliar application at a concentration of 50 ppm had the greatest effect on vegetative growth indicators. Also, in the same experiment, it was found that the use of GA3 in high concentrations has the negative effects on flowering and fruit growth., while it increases the amount of runner production. Also, IBA at a concentration of 60 ppm was the most effective treatment in fruit indices. In the second experiment, gibberellin at a concentration of 100 ppm was the most effective treatment in fruit and its biochemical traits, while NAA auxin in the second experiment showed a lower response to fruit than IBA auxin in the first experiment.
Pomology
T. Rasteh; J. Erfani moghadam; S.S. Marashi
Abstract
IntroductionThe date palm (Phoenix dactylifera L.) belongs to the family Arecaceae is a dioecious trees. Due to the problems of non-overlapping flowering of some male and female palm trees, commercial date production requires artificial pollination. Temperature is an important environmental factor influencing ...
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IntroductionThe date palm (Phoenix dactylifera L.) belongs to the family Arecaceae is a dioecious trees. Due to the problems of non-overlapping flowering of some male and female palm trees, commercial date production requires artificial pollination. Temperature is an important environmental factor influencing the pollination, fertilization and fruit set of the date palm. Availability of efficient male pollinators are of great importance in date palm production chain and for regular yearly bearing as the quantity and quality of pollen is a yield determining factor. The flowering and pollination period of date palm varies upon cultivar, geographic location and climatic conditions. However, frequent asynchronous flowering of date palm male and female trees occur due to climatic changes and abiotic stress. In such cases, farmers may pollinate their trees with pollen of a known male conserved at ambient conditions from the previous season; however, this is mostly result in a low fruit set and yield.Materials and MethodsIn this study, a factorial test was performed based on a completely random design with three replications at the laboratory of the Horticulture department at Ilam University to determine the rate of germination in five male date palm cultivars. The first factor consisted of nine temperature levels of 15, 18, 21, 24, 27, 30, 33, 36 and 39 and the second factor referred to the cultivar of the pollinator which had five levels of ‘Ghanami Sorkh’, ‘Ghanami Sabz’, ‘Sabz Parak’, ‘Nare Pakutah’ and ‘Khareji’. The pollen of the above-mentioned cultivars was obtained from the date palm Germplasm collection at the Date Palm and Iranian Tropical Fruits Institute in the city of Ahwaz. In the early days of the flowering season (March), the cultivars under study were identified and labeled. They were then checked on a daily basis and whenever the sheaths were ripe enough, they were picked and preserved in a sterile environment in room temperature. After the sheaths opened, the flower clusters were dried in the same environment and at the same temperature. Then, the cluster strings were separated and kept in a freezer at -18 °C until it was time for the test. Viability and vitality of the pollen was specified through the dying method using Acetocarmine solution.Results and DiscussionThe results showed that there was a significant difference among cultivars, temperature and interactions of them at the level of 1%. Among the studied temperatures, the highest germination of pollen grains in all cultivars occurred at 30 °C, followed by 33 °C and 27 °C, respectively, and the lowest germination percentage were obtained at 15 °C. Among cultivars, the percentage of pollen germination in ‘Ghanami Sorkh’ was quite high (92.45%), and ‘Nare Pakutah’ (87.33%), also, simultaneously ‘Sabz Parak’ (84.82%) and in the ‘Khareji’ cultivar was the lowest. However, the percentage of pollen germination in ‘Ghanami Sorkh’ cultivar was higher than 59% under a wide range of temperature from 21 to 39 °C. Furthermore, the percentage of Pollen germination was reduced rapidly at temperatures less than 21 Cº and reach 15.85% in 15 °C. The germination percentage of pollen grains in ‘Nare Pakutah’ cultivar in the temperature range of 21 to 39 degrees Celsius was higher than 57%. The germination percentage of pollen grains in ‘Sabz Parak’ cultivar decreased with less acceleration than ‘Ghanami Sorkh’ at lower and upper temperatures of 30 °C, so that at 36 and 39 °C had the highest amount of germination compared to the other cultivars. Also, the germination rate of pollens in ‘Ghanami Sorkh’ cultivar were investigated above 57% in the wide temperature range from 21 to 39 °C.ConclusionAccording to the findings of this study, the timing of pollination plays a crucial role in the fertility of male date palm cultivars, with the optimal temperature being around 30°C. It is essential to select cultivars that exhibit a high rate of pollen germination and contribute positively to fruit properties. Male cultivars such as 'Ghanami Sorkh', 'Sabz Parak', and 'Nare Pakutah' demonstrated a broader range of optimum temperatures for pollen germination. Therefore, these cultivars are recommended for climates characterized by significant temperature fluctuations during the flowering period of female date palms.
Pomology
H. Sartip; A. A. Shokouhian; E. Chamani; A. Ghanbari
Abstract
IntroductionSweet cherry is very popular due to its early maturity, high transportability, attractive appearance and good taste of the fruit. The high content of sugars, ascorbic acid, vitamins, carbohydrates and organic acids in the fruit increases the interest in this product both in industrial gardening ...
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IntroductionSweet cherry is very popular due to its early maturity, high transportability, attractive appearance and good taste of the fruit. The high content of sugars, ascorbic acid, vitamins, carbohydrates and organic acids in the fruit increases the interest in this product both in industrial gardening and home gardening. The damage caused by cold in the critical stages of plant growth is one of the important factors in reducing the yield of plants all over the world. Salicylic acid is one of the phenolic compounds that is produced by the roots, and by reducing the activities of reactive oxygen species, it increases the resistance of plants to various environmental stresses (Mahmoudi et al., 2019). Salicylic acid not only plays an important role in determining the quality, color and taste of grape fruit (Hajivand & Rahmati, 2018), but also in the plant's response to environmental stresses such as drought (Miura & Tad, 2014), cold (Kosova et al., 2014) salinity (Noreen et al., 2014) and heavy metal stress (Mahmoudi et al., 2019) are effective. Commercial compounds such as plant growth regulators, including antiperspirant and antifreeze substances, are also used to increase cold resistance or delay the breaking of bud stagnation in horticultural crops (Mahmoudzade et al., 2012). Another way to reduce spring cold damage is to use Natural Plant Antifreeze. These materials either act as a mechanical barrier to prevent the formation of ice crystals on sensitive plant tissues or activate cold resistance systems in the plant (Hajivand & Rahmati, 2018).Materials and MethodsIn order to investigate the effect of the application of growth regulators, on the cold resistance of the cherry tree variety "Siah Daneh Mashhad", a factorial experiment was conducted in the form of a randomized complete block design with 3 factors of growth regulators each at 3 levels. (salicylic acid: zero, 1.5 and 3 mM), (natural antifreeze Thiofer: zero, 2.5 and 5 per 1000) and (soybean oil: zero, 2.5 and 5 per 1000)} and in 4 repetitions It was performed in a commercial garden located in Serain city in 2018 and 2019.Results and DiscussionThe results of the variance analysis revealed that the three-way interactions of the experimental factors significantly influenced the percentage of healthy pistils and the duration of flowering cessation at the 1% probability level. The highest percentage of healthy pistils, reaching 69.25%, was observed in the treatment involving foliar spray application of salicylic acid (1.5 mM) combined with soybean oil (5/1000) and foliar spraying of Thiofer natural antifreeze (5/1000). Furthermore, the combined effect of salicylic acid and natural antifreeze was found to be the most effective in delaying the onset of flower opening. The highest amount of ion leakage percentage was observed in the control treatment and the lowest amount was observed in the 3 mM salicylic acid foliar treatment along with soybean oil (5 per 1000) Thiofer. According to the data variance analysis table (Table 1), the ion leakage index was affected by the simple effect of salicylic acid, soybean oil and antifreeze and the interaction effect of salicylic acid oil × salt, salicylic acid × soybean oil, and soybean oil × antifreeze. The activity of malondialdehyde was affected by the simple effect of salicylic acid and soybean oil and the interaction effect of salicylic acid × year and year × soybean oil (Table 1). The total phenolic content was also affected by the simple effect of salicylic acid and soybean oil (Table 1). According to Figure 11, increasing the concentration of salicylic acid increased the content of total phenol, so that the highest content of total phenol (53.22%) was obtained in the treatment of 3 mM salicylic acid, while there was no significant difference in the treatment of 1.5 mM salicylic acid. . To adapt to the cold, phenolic compounds accumulate in plants, which are related to the antioxidant capacity of the plant (Mozafari &Yazdan Panah, 2018). A decrease in temperature increases the accumulation of phenolic compounds in the plant and can act as a mechanism to adapt and overcome the oxidative stress caused by low temperature (Balasundram et al., 2007). Balasundram and colleagues (Balasundram et al., 2007) noted that grape plants exhibit an accumulation of phenolic compounds and proteins while maintaining membrane stability at low temperatures. This accumulation leads to reduced production of malondialdehyde, enhancing the plant's adaptability and tolerance to cold temperatures, thereby reducing the risk of freezing. Similar observations of increased phenolic compound levels during cold adaptation have been reported in pistachios (Palonen, 1999) and apples (Huang & Wang, 1982). Chen and Tian (Chan & Tian, 2006) reported an increase in phenolic compound accumulation following enhanced activity of phenylalanine ammonia-lyase enzymes in grapes treated with salicylic acid. From their findings, they concluded that salicylic acid plays a pivotal role in the biosynthesis of phenolic compounds and the activation of plant defense genes.ConclusionAccording to the observations of this research, it can be concluded that the use of salicylic acid along with soybean oil and natural antifreeze of Thiofer is a suitable solution in order to delay the opening time of flowers and also to increase the indicators of cherry cold resistance against The tension is cold.
