Pomology
Saeedeh Keivanfar; Davood Hashemabadi; Behzad Kaviani
Abstract
Introduction Olive (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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Introduction Olive (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 Methods A 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.
Pomology
Fatemeh 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 NAA foliar application at different days after full bloom on controlling fruit drop and improving physical and biochemical attributes of ‘Red Delicious’ apple fruits. Findings described here may help to understand the effects this PGR on apple quality and also help on the development of strategies to reduce post-harvest losses of apple fruits.
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 replications 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
Y. Salahvarzi; Javad Samimi; Ali Tehranifar; Nasser Beikzadeh
Abstract
IntroductionPear (Pyrus communis L.) belongs to the Rosaceae family and is native to Western Asia and Eastern Europe. Fire blight has five phases or five important stages of contamination, namely blossom blight, branch and leaf blight, fruit blight, main branches and trunk blight, and finally root blight. ...
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IntroductionPear (Pyrus communis L.) belongs to the Rosaceae family and is native to Western Asia and Eastern Europe. Fire blight has five phases or five important stages of contamination, namely blossom blight, branch and leaf blight, fruit blight, main branches and trunk blight, and finally root blight. The USDA standard system is proposed and implemented by the United States Department of Agriculture (USDA). Additionally, the sensitivity of grafted cultivars to fire blight can be determined using the Gardner scale, which measures the percentage of blighted aerial parts of pear seedlings. The Erwinia amylovora bacterium obtains its energy by consuming carbohydrates, and an increase in carbohydrates in plant tissues leads to increased absorption of this bacterium. Furthermore, the cellular pH of the host plant also affects the growth and proliferation of fire blight bacteria, with the optimal pH range being between 5 and 10.Material and mehodMaterials and methods The rootstocks used in this experiment were Dargazi and Pyrodwarf, while the pear cultivars were Koshia and Dargazi. The experiment was conducted in both orchard and greenhouse conditions. In the orchard, a factorial experiment based on a randomized complete block design was carried out with five replications. The factors studied were the rootstocks (Dargazi and Pyrodwarf) and the pear cultivars (Koshia and Dargazi). In the greenhouse, a factorial experiment based on a completely randomized design was conducted with three replications. The factors studied were the rootstocks (Dargazi and Pyrodwarf) and the pear cultivars (Dargazi and Koshia). The Gardner scale was used to measure the severity of fire blight infection. Additionally, measurements of sucrose, sorbitol, and pH levels in the leaf tissue were taken The sucrose content in the leaf tissue of Koshia/pyrodwarf rootstock increased from day 0 to 6, reaching its highest level (10%) on the 6th day, and then decreased to 5% on the 12th day. In Dargazi/Pyrodwarf rootstock, the sucrose content increased from day 0 to 6, reaching its highest level (8%) on the 6th day, and then decreased to 5% on the 12th day. In Dargazi/Dargazi rootstock, the sucrose content increased from day 0 to 6, reaching its highest level (7%) on the 6th day, and 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, reaching its highest level (2%) on the 6th day, and then decreased to 1% on the 12th day. In Dargazi/Pyrodwarf rootstock, the sorbitol content increased from day 0 to 6, reaching its highest level (1.5%) on the 6th day, and then decreased to 1% on the 12th day. In Dargazi/Dargazi rootstock, the sorbitol content increased from day 0 to 6, reaching its highest level (1%) on the 6th day, and then decreased to 0.5% on the 12th day. On the other hand, the pH of the leaf tissue in Dargazi/Pyrodwarf rootstock remained constant at 6.2 from day 0 to 12. The pH of the leaf tissue in Dargazi/Dargazi rootstock was constant at 6.2 from day 0 to 6, and then increased to 7.4 on the 12th day. The data collected from both the orchard and greenhouse experiments were analyzed to determine the effects of rootstock and cultivar on fire blight resistance. Results and discussionOverall, the results of the experiment showed that the Koshia/Dargazi combination exhibited more resistance to fire blight compared to the Koshia/Pyrodwarf combination. The Dargazi/Pyrodwarf and Dargazi/Dargazi combinations were highly resistant to fire blight. The symptoms of fire blight were not observed in the Dargazi/Dargazi combination even 18 days after inoculation. The pH levels in the leaf tissue varied among the different combinations. The Koshia/Pyrodwarf and Koshia/Dargazi combinations showed fluctuations in pH levels, while the Dargazi/Pyrodwarf and Dargazi/Dargazi combinations had more consistent pH levels. The amount of sorbitol and sucrose sugars decreased slightly in the resistant Dargazi cultivar until 12 days after bacterial induction. In the Koshia/Pyrodwarf combination, the amount of these sugars decreased with the intensity of bacterial development in the tissues. However, in the Dargazi/Dargazi combination, the amount of sugars remained constant due to the lack of bacterial penetration and the cultivar's resistance to the disease. These findings suggest that using resistant rootstocks or inter-stocks can contribute to disease resistance in pear trees. The results of this experiment provide valuable information for researchers and growers in selecting appropriate rootstocks and cultivars to mitigate fire blight infection.Conclusionresults showed that the Koshia/Dargazi combination had higher resistance to fire blight compared to the Koshia/Pyrodwarf, and the pH and carbohydrate content in the leaf tissue of the rootstock influenced the growth and proliferation of fire blight bacteria.The results of this study showed that there are different degrees of resistance to fire blight among the studied combinations, which indicates the existence of sufficient potential for the program to breed and improve pear to resist this disease. Dargazi cultivar has a very high degree of resistance to fire blight in both orchard and greenhouse conditions. In general, the resistant of Dargazi rootstosk has some effect of its resistance on the sensitive Koshia cultivar.
Pomology
Mansour Jalali; Noorolah Moallemi; Esmaeil Khaleghi; Shoreh Zivdar; Mostafa Rahmati-Joneidabad
Abstract
IntroductionThe date palm 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 ...
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IntroductionThe date palm 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 conducted to investigate the effect of manual and chemical thinning on qualitative characteristics in different stages of date fruit development of the Khadrawi cultivarMaterials 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/gr FW), total soluble tannin (mg/gr FW), ascorbic acid (mg/gr FW), poly-galacturonase enzymes (U/gr FW), methyl pectin esterase (U/gr FW), cellulase (U/gr FW) and invertase (U/gr 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 works in the groves, which improves the quality characteristics of the fruit. In general, the although, hand thinning is more expensive, time-consuming and relatively more difficult than chemical thinning, but our finding showed that the quality of date fruit of Khazrawi cultivar improved by removing 25% of the total number of strands and chemical thinning with 100 mg/liter naphthalene acetic acid and these treatments is recommended for palm growers.
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 (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 on GN15 rootstock, in order to introduce 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. 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.
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.
Conclusion
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 as a source of good germplasm for breeding programs. Cultivars and genotypes with higher percentage of kernels had thinner shell, more patterns on the skin, and light to medium kernel color. 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.
Pomology
F. Azarmi-Atajan; M.H. Sayyari Zahan; A. Mirzaei
Abstract
Introduction
Phosphorus (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 ...
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Introduction
Phosphorus (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 Methods
In 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 Discussion
The 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.
Conclusion
Unlike 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
Sayeede Khodaei; Ebrahim Ganji Moghaddam; Mahbube 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
Zohre Rohi Vishekaii; Ali Soleimani; Mahmmod Ghasemnezhad; Akbar 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
Alireza 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
Esmaeil Khaleghi; Masumeh Zamani Dehbari; Noorollah 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.R. 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.
Pomology
M.J. Karami
Abstract
Introduction
The Rotabi grape cultivar holds significant importance in the Bavanat region of Fars province. There are two distinct methods of pruning employed for this cultivar: Cane pruning and Spur pruning. These methods vary primarily in the length of one-year-old wood that is preserved after ...
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Introduction
The Rotabi grape cultivar holds significant importance in the Bavanat region of Fars province. There are two distinct methods of pruning employed for this cultivar: Cane pruning and Spur pruning. These methods vary primarily in the length of one-year-old wood that is preserved after pruning. Cane pruning involves retaining long fruiting canes, typically those with more than 3 buds per cane. Conversely, Spur pruning utilizes shorter canes, usually those with 1-2 buds. The common method of training Rotabi vines in Shiraz vineyards is in the form of bush training. This method of vine training is compatible with spur pruning, in which the canes are usually pruned into 2 to 3 buds. For this reason, there is not enough information about the response of this cultivar to cane pruning. This study was conducted in order to determine the correct method of pruning Rotabi vines based on scientific principles appropriate to its genetic characteristics.
Materials and Methods
This study was performed on 17-year-old vines of Rotabi cultivar in one of the vineyards of Shiraz of Fars province (Iran). In this study, the response of this cultivar to two levels of pruning severity (light pruning with formula 40 + 20 and severe with formula 20 + 20) and three levels of the number of the buds per cane (3, 6, and 9 buds) during three years in Shiraz region of Fars province (Iran) was evaluated. A factorial experiment based on randomized complete block design was used with three blocks. Quantitative and qualitative characteristics such as yield, average weight of cluster, average number of clusters/vine, titratable acidity (TA), pH of fruit juice, TSS%, bud fruitfulness, the average weight and the number of berries/bunch was recorded.
Results and Discussion
Results showed that effects of pruning severity on yield, the number of bunch/vine, bunch weight, pH, bud fruitfulness and berry weight was significant (p≤0.01). Effect of cane length on yield, the number of bunch/vine, bunch weight, bud fruitfulness and the number of berry/bunch was significant (p≤0.01). but on berry weight, TA, pH and TSS% of fruit juice was not significant. Interactions between pruning severity with buds per bearing unit on yield, the number of bunch/vine, berry weight and the number of berry/bunch (p≤0.01) and on TA (p≤0.05) was significant. The highest fruit production per hectare (yield) and the number of bunches per vine were obtained in vines subjected to light pruning. However, in vines that underwent severe pruning, bud fruitfulness and berry weight were greater than in lightly pruned vines. The most substantial yield was achieved with 6-bud and 9-bud canes. Yet, the highest number of bunches was observed in vines with 3-bud and 6-bud canes. Bud fruitfulness reached its peak in the 6-bud cane category, while it was at its lowest in the 3-bud cane group. The number of berries was the same in the 3-bud and 9-bud cane treatments, and it exceeded the number of berries in the 6-bud cane group. Notably, due to the interaction between pruning severity levels and the number of buds per cane, the highest yield was recorded in light pruned vines that underwent cane pruning, specifically in the groups of light pruning with 6-bud canes and light pruning with 9-bud canes. The highest number of berries was observed in light pruning with 9 buds. As a result of this study, it was found that by increasing the number of buds/cane or in other words by increasing the cane length to 6 and 9 buds in this cultivar, the fruit yield/vine increased, and but fruitfullness decreased. Increased yield in light pruning can be due to the increase in the number of bunches/vine due to the increase in the number of buds in this type of pruning. Therefore, to increase the yield of this cultivar, cane pruning + 9 buds/cane should be applied. This type of pruning is not compatible with conventional pruning methods (spur pruning) in the cultivation area of this cultivar. Therefore, it is necessary to develop training systems compatible with cane pruning (such as four-arm kniffin system) in these areas.
Conclusion
While severe pruning led to higher bud fruitfulness, it resulted in lower fruit production per vine (yield) compared to lightly pruned vines. One possible explanation for this difference is that light pruning retained more buds compared to severe pruning. As a consequence, light pruning produced more bunches, ultimately yielding a greater quantity of fruit compared to the severe pruning method. The highest yield (31.3 t/ha) and the highest number of bunches/vine (103) was observed in light pruned vines. Also, the highest yield was obtained in 6-bud and 9-bud canes (31.4 and 31.3 t/ha) respectively. Yield increased with increasing cane length to 6 or 9 buds. Therefore, in order to achieve more yields in this cultivar, cane pruning of at least 6 buds should be applied. But in the end, for better management of vines and the possibility of using standard vine training systems compatible with cane pruning, preferably cane pruning with 9-bud/vine is recommended.
Pomology
A. Ehtesham Nia; Sh. Taghipour; S. Siahmansour
Abstract
IntroductionWhile grapes are considered as non-climacteric fruits, during the post-harvest stages, due to the softening of the tissue, it is very prone to decay, which shortens its post-harvest life. Today, due to the desire of consumers to use high quality food, the use of biodegradable films and coatings ...
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IntroductionWhile grapes are considered as non-climacteric fruits, during the post-harvest stages, due to the softening of the tissue, it is very prone to decay, which shortens its post-harvest life. Today, due to the desire of consumers to use high quality food, the use of biodegradable films and coatings with antimicrobial properties, is a suitable alternative to synthetic preservatives, in order to maintain food security and prevent wastage of significant capital. Edible coatings are edible thin layers that are used to increase the shelf life and quality of fruits. This material increases the quality and health of the product by creating a semi-permeable barrier to water vapor and oxygen and carbon dioxide gases between the product and the environment, and to prevent anaerobic respiration, it absorbs a certain amount of gases and to this Sequence increases product shelf life. One of the most important ways to increase the shelf life and maintain the quality of agricultural products, especially fruits, is the use of edible coatings on the crop surface. Chitosan is one of the most important natural derivatives of chitin, of which about 50% of its acetyl’s groups have been removed. Due to the fact that Aloe vera gel has no taste and odor, can be considered a good option as a cover for fruits after harvest and due to its elasticity and strength solution in water, as a suitable layer on the product. Located and protects the fruit from mechanical damage and moisture loss. Material and Methods In this study, 12-year-old mature grape trees of ‘Asgari’ cultivar in the scaffolding garden of Abestan region of Khorramabad city in 1398 were studied. In the pre-harvest stage, chitosan was sprayed on the tree and in the post-harvest stage, Aloe vera gel was applied by dipping the fruit in Aloe vera gel in the laboratory. After treatment, the fruits were stored in the refrigerator at a temperature of 4 ± 0.5 ° C and were examined at different time stages for quantitative and qualitative characteristics of the fruit. 20 identical grape trees (in terms of fruit size and load, with 50 to 70 annual branches in 8-14 buds) selected and grape clusters with different concentrations of chitosan (control (distilled water), 2 and 3 Percentage of chitosan) at different stages of growth (fruit set), 35 and 50 days later) were sprayed directly with 4 liters per vine, by hand sprayer (2 ml Tween 80% was added as the active surfactant). For this stage, immediately after harvesting the grapes, take them to the laboratory and immerse them in concentrations (zero, 25 and 33%) of Aloe vera gel for 10 to 20 seconds and then in the air. They dried. Then, grape fruits weighing about 360-300 g in each experimental unit were stored for 28 days at 4 ° C and examined. This study was performed as a factorial experiment (2 factors) in a completely randomized design with three replications. The first factor is the effect of the treatments studied in seven levels including: control, 2% chitosan (CTS 2%), 3% chitosan (CTS 3%), chitosan 2% + Aloe vera gel 25% (AVG 25% + CTS 2%), chitosan 3% + Aloe vera gel 25% (AVG 25% + CTS 3%), 2% chitosan + 33% Aloe vera gel (AVG 33% + CTS 2%), chitosan 3% + Aloe vera gel 33% (AVG 33% + CTS 3%) and the second factor was storage time at five levels (zero, 7, 14, 21 and 28 days after harvest). Data analysis was performed using SAS software and a significant difference between treatments for each trait with a minimum significant difference at the probability level = 0.05 α was determined. Results and Discussion The results of analysis of variance showed that the effect of treatment and storage time on the desired traits was significant at the level of one percent. Fruits treated with chitosan and Aloe vera gel had higher texture firmness, taste index, phenolic content, antioxidant activity and titratable acids and caries index and pH were lower than the control. The highest content of phenol, antioxidant, flavor index and titratable acidity in all five measurement times belonged to 2% chitosan treatments with both concentrations of Aloe vera gel (25 and 33%) and the lowest amount belonged to the control treatment. In control treatment, the percentage of caries index increased during storage and in grapes treated with chitosan and Aloe vera gel, the caries process was slower and the lowest rate of caries was observed in 2% chitosan treatment with aloe vera gel on the 14th day. In general, it was observed that pre-harvest application of chitosan and post-harvest Aloe vera gel increase the post-harvest life of ‘Asgari’ grapes and improve its quality traits. Chitosan creates a barrier with selective permeability to oxygen and carbon dioxide gases, and by placing carbon dioxide at a higher level and reducing oxygen, it creates a modified atmosphere around the fruit, which reduces respiration and ethylene production. As a result, it reduces the aging process and reduces the consumption of organic acids and sugars and prevents the increase of pH. Low pH prevents browning of the fruit due to the activity of catechins and chlorogenic acid enzymes. Aloe vera gel coating maintains and increases the antioxidant capacity of the whole fruit by reducing fruit juice loss, reducing respiration, reducing ethylene production and delaying aging. Conclusion The combined treatment of chitosan 2% and Aloe vera gel (25 and 33%) increased fruit firmness, titratable acidity, taste index, total phenol content and antioxidant activity of grapes and reduced pH and caries index. Application of these treatments increased the post-harvest life of ‘Asgari’ grapes by 14 days, so it can be stated that the use of chitosan in the pre-harvest stage and the use of Aloe vera gel in the post-harvest stage as biodegradable and natural compounds to increase Shelf life of ‘Asgari’ grape fruit is recommended.
Pomology
E. Ganji Moghaddam; A. Mostafapoor; M. Zamanipour
Abstract
Introduction
Iran is undoubtedly one of the most important and potential areas of fruit production in the world due to having diverse climatic zones and also the existence of different cultivars and rich germplasm for many horticultural products. Meanwhile, cherries are very important because of their ...
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Introduction
Iran is undoubtedly one of the most important and potential areas of fruit production in the world due to having diverse climatic zones and also the existence of different cultivars and rich germplasm for many horticultural products. Meanwhile, cherries are very important because of their good taste, high nutritional value and short ripening period. Despite the relatively high production, Iran ranks 46th among cherry exporting countries, which can be attributed to the non-uniformity of cultivars in orchards and mixed cultivation of several cultivars, lack of attention to the incompatibility of cherries and the lack of suitable pollinizer, the drought, the lack of availability of cultivars and rootstocks suitable for climate and soil changes, pest damage, etc. At present, in Khorasan-Razavi province, Takdane cherry trees have not yield well, which experts have sometimes attributed to self-incompatibility or lack of proper pollinizer. The gardener spends a lot of money to build a orchard that is not profitable; Therefore, instead of cutting down the trees, it is suggested to do grafting and in one turn, to replace the cultivars of your orchards with cultivars suitable for the region, which have good yield, quantitative and qualitative characteristics, and are self-fertile. Top-working is a new approach to increasing the productivity of old orchards, rejuvenating and changing their varieties. With this aim, a research was conducted in Razavi Khorasan province over three years.
Matherial and Methods
This project was carried out in three regions of Chenaran, Neishabur and Torghabeh Shandiz and included three independent experiments. After the growth of scion, the degree of adaptation and percentage of grafting success, vegetative growth of scion, beginning of fruiting, yield, and economic evaluation were investigated. In the first experiment, in order to determine the type of grafting and the cultivar on the success and percentage of grafting, a factorial experiment was used in the form of a randomized complete block design in three replications and each replication included 3 transplants. The first factor was grafting type in two levels (bark grafting and cleft grafing) and the second factor was cultivar in three levels (Stella, Sweetheart and Sunburst). In the second experiment, the evaluation of the effect of tree age and type of grafting on success percentage of grafting was carried out. In order to carry out this stage of the factorial experiment, two factors were used. The first factor was tree age at two levels (10 and 20 years) and the second factor was the type of graft (bark grafting and cleft grafing) used. In the third experiment, the effect of nurse branch and cultivar on the percentage of grafting success was investigated. This stage was a two factorial experiment where the first factor was the presence or absence of the nurse branch and the second factor was the cultivar in three levels (Stella, Sunburst, Sweetheart), used.
Result and Discussion
The results of first experiment showed that the Sunburst cultivar with the highest percentage (86.8%) and the Stella cultivar had the lowest percentage (64.3%) of grafting success. This result is consistent with the reports of Soleimani et al. (2008) who found that the success percentage of different cultivars were significantly different from each other. Also, cleft grafting had a higher percentage than bark grafting. Therefore, cleft grafting was more successful at 65% than bark grafting at 13%. These results are consistent with the findings of Mahmouzadeh (2012), who reported that the cleft graft had a higher percentage of success other than bark grafting.
The results of second experiment showed that as the age of the tree increased, the percentage of grafting decreased greatly. The grafting percentage was about 68% in young trees and 8% in trees over 25 years old. Based on this, it is not recommended to perform branch grafting in old trees. The results of third experiment showed that the maintenance of the nurse branch in the cherry tree does not have a significant effect on grafting. The grafting percentage was about 78% in trees without nurse branches and about 63% in trees with nurse branches. Based on this, it is not recommended to keep the nurse branch in the cherry branch.
Analysis of variance of the simple and mutual effects of year and branching location on grafting percentage of cherry trees was significant at 1% level and it was found that the percentage of grafting was higher in the second year than the first year due to the skills of transplanters. Also, the percentage of graftng success in Torghabeh and Shandiz, was higher than Chenaran and Neishabur. These results are in agreement with the findings of Mng'omba et al. (2010) who reported that grafting success largely depends on the skill of the transplanters, is consistent.
Conclusion
In general, Top-working in sweet cherry trees is recommended in order to change the variety of the orchard and also, improve the productivity of the orchard.
Pomology
M.A. Ahmadi; S. Daghighi; F. Azarmi-Atajan; H. Bayat
Abstract
Introduction
Jujube (Ziziphus jujuba Mill.) as one of the invaluable medicinal plants, is widely used in the pharmaceutical industry due to its vitamins, mucilage, antioxidants, alkaloids and phenolic compounds. South Khorasan province is the most important area of jujube fruit production in Iran. Optimum ...
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Introduction
Jujube (Ziziphus jujuba Mill.) as one of the invaluable medicinal plants, is widely used in the pharmaceutical industry due to its vitamins, mucilage, antioxidants, alkaloids and phenolic compounds. South Khorasan province is the most important area of jujube fruit production in Iran. Optimum supply of nutrients in fruit trees can increase fruit quality. Calcium is one of the most important elements that can affect quantity, quality, storability and marketability of many horticultural crops. Due to the relatively high amount of lime in the agricultural soils of South Khorasan province, the amount of calcium in these soils is almost high. However, due to low mobility of calcium from soil to plant, calcium deficiency is common in horticultural plants. Also, potassium is required for cellular osmotic and ionic balances, electrochemical processes, neutralization of organic acids, regulation of stomatal function, cell division, enzyme activation, protein synthesis, as well as the synthesis and translocation of sugars. Foliar spraying is an effective way to supply nutrients needed by plants, especially in calcareous soils with high pH. In this method, nutrients are directly available to different parts of the plant in a short period of time. Studies have shown that leaf feeding with calcium and potassium can be useful for increasing the qualitative characteristics of fruit in most products, especially in arid and semi-arid regions. Nevertheless, little information is available regarding the foliar application of this element on jujube plant. Hence, the current research was aimed to investigate the effects of foliar application of calcium chloride and potassium sulfate on physicochemical properties and quality of fresh jujube fruit.
Materials and Methods
In order to investigate the effect of foliar application of calcium chloride and potassium sulfate on the physical and biochemical properties of the fruit of the jujube plant, two separate factorial experiment was conducted in the form of a randomized complete block design in three replications in two areas of Siojan and Mazhan, Khosef city in 2022. Experimental treatments included calcium chloride (0, 0.5 and 1%) and potassium sulfate (0, 0.1 and 0.3%). Fresh fruit was harvested at a crisp mature (white-red) stage mid in August. Data were analysed using SAS software (ver. 9.4) and comparison of means was made with LSD test at 1 and 5% probability.
Results and Discussion
The results of analysis of variance showed that calcium chloride foliar application in Siojan garden had significant effect on the physical and biochemical characteristics of jujube fruit. So that the highest fresh weight (4.07 gr), dry weight (1.89 gr), length (29.11 mm), diameter (21.52 mm) and texture firmness (18.81 N/cm2) of fruit were obtained from the level of 0.5% calcium chloride. Also, the foliar spraying treatment with 0.5% calcium chloride had the highest amount of carotenoid and total phenol in the fruit. The highest amount of calcium and potassium in the fruit was obtained from the level of 1% calcium chloride. The effect of foliar application of calcium chloride on physical and biochemical properties of jujube fruit in Mazhan garden was significant. In Mazhan garden, the highest fresh weight (3.9 gr), dry weight (1.37 gr), length (28.41 mm), diameter (20.91 mm) and texture firmness (18.61 N/cm2) of fruit were obtained from foliar application of 0.5% calcium chloride. The highest amount of carotenoids (0.443 mg/100 g of fresh weight) and phenol (9.53 mg of gallic acid per 100 g of fresh weight) in Mazhan garden was obtained from the level of 0.5% calcium chloride. The content of calcium and potassium of jujube fruit in Mazhan region was maximized with the application of 1% calcium chloride. The results showed that the application of potassium sulfate in Siojan garden had an significant effect on the physical and biochemical characteristics of the fruit. The highest fresh weight (3.63 gr) and dry fruit weight (1.89 gr), length and diameter and texture firmness of fruit was obtained from the level of 0.3% potassium sulfate. Also, the highest amount of biochemical indices of jujube fruit in Siojan garden was obtained from the level of 0.3% potassium sulfate. The interaction effect of foliar application of calcium chloride and potassium sulfate on fresh and dry fruit weight, fruit length and carotenoids of fruit in Siojan garden was significant. In Mazhan garden, the fresh and dry weight of fruit, amount of carotenoids and total phenol of fruit were affected by the interaction effect of experimental treatments, and the highest level of these characteristics was obtained from the level of 0.5% calcium chloride and 0.3% potassium sulfate.
Conclusion
The results of foliar spraying of calcium chloride and potassium sulfate in both studied orchards showed that these treatments, both solely and in combination, had a positive and significant effect on various characteristics of jujube fruit. So the highest physical and biochemical characteristics of the fruit were obtained from the simultaneous application of 0.5% calcium chloride and 0.3% potassium sulfate. Therefore, Based on the results of this research, foliar spraying 0.5% calcium chloride and 0.3% potassium sulfate can have an effective role in increasing the quantity and quality of jujube fruit.
Pomology
A. Fatemi; A. Safari; M. Saeidi; Z. Kolahchi
Abstract
Introduction
Drought is the most important limiting factor for the yield and quality of products in the world. Fertilizer application can mitigate drought stress in plants. Most farmers prefer to use inorganic (chemical) fertilizers because of their fast impact on plant growth. The reasonable ...
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Introduction
Drought is the most important limiting factor for the yield and quality of products in the world. Fertilizer application can mitigate drought stress in plants. Most farmers prefer to use inorganic (chemical) fertilizers because of their fast impact on plant growth. The reasonable cost of inorganic fertilizers and their availability are the other reasons. However, the long-term effects of organic fertilizers on plant growth and soil fertility has been proved. The grapevines are one of the most important garden products in the world as well as in Iran. It has been reported that the application of biochar has significant effects on soil fertility as well as plant growth. Biochars have properties such as highly porous structure, high specific surface area, higher water holding capacity of the soil, the long-term stability in the soil. In addition, our previous study indicated that it could decrease the hazard of sodium in soil compared with compost. In Iran, the cultivation area of grapevines was the second grade after the pistachio cultivation area in 2019. According to statistical data on agriculture in 2019, the cultivation area of irrigated and rain-fed grapevines in Kermanshah province was 7710 and 1515 ha, respectively. According to this report, the production of irrigated and rain-fed grapevines in Kermanshah province in 2019 was 82718 and 1763 tons, respectively. The effect of application of some inorganic and organic fertilizers under drought stress on yield, water use efficiency, and some biochemical characteristics of the grapevine leaves cultivar Bidane-Ghermez has been previously studied. In this research, the effect of drought stress and the application of potassium sulfate, compost, and biochar on antioxidant activities of the grapevine leaves cultivar Bidane-Ghermez was investigated.
Materials and Methods
A greenhouse study with a factorial experiment based on a block of randomized completely design was conducted with fertilizer treatments including control, potassium sulfate (1250 mg kg-1), compost (5% w/w), and biochar (10% w/w) without and with drought stress conditions (80 and 40% FC, respectively) during 2017-2018. For this research, the biochar was produced from apple tree pruning under low oxygen conditions by slow pyrolysis at 400 ◦C. The compost was purchased from the municipal compost factory of Kermanshah province. To evaluate drought stress and inorganic and organic fertilizers' application on antioxidant enzymes activities, the superoxide dismutase and peroxidase activities and total soluble protein of grapevine leaves were determined. The data were analyzed by ANOVA and the mean of studied characteristics was compared by Duncan’s test at 5% probability level using SAS software.
Results and Discussion
the results indicated that the interaction effect of fertilizers treatments and drought stress on the superoxide dismutase and peroxidase activities as well as total soluble protein was significant (P<0.01). Under drought stress conditions, among fertilizers’ treatments, the activity of superoxide dismutase for potassium sulfate was significantly lower than compost and biochar treatments (P<0.01). The results also showed that the peroxidase activity for compost was significantly higher than potassium sulfate and biochar treatments (P<0.01). Besides, the highest total soluble protein amount was found for biochar treatment (P<0.01).
Conclusion
according to the results of this study, it can be concluded that the increase of total soluble protein of grapevine leaves under drought stress conditions by biochar application contributed to the increase of superoxide dismutase and peroxidase activities also increasing the bioavailability of macro-and micronutrients. Biochar application increased significantly the potassium concentration of the leaves of the grapevines. Potassium regulates water movement at the plant and also provides a higher relative water content of grapevine leaves. Moreover, potassium decreases the non-stomatal effects are also attributed to stomatal closure during drought stress conditions. Furthermore, potassium contributes to protein synthesis. Biochar application also increased the phosphorus, copper, and magnesium of the leaves of the grapevine. Higher concentration of phosphorus under drought stress conditions caused the grapevine leaves to suffer less from phosphorus deficiency. Copper exists in superoxide dismutase and is considered a key player in superoxide detoxification. Under drought stress conditions, higher manganese concentration by biochar application resulted in more protection of the cellular membrane against Reactive Oxygen Species (ROS). For fertilizer recommendation in order to reduce drought stress effects on some antioxidant enzymes activities of Bidane-Ghermez grapevine leaves, the application of biochar is recommended first then potassium sulfate and compost.
Pomology
M. Fattahi; A. Mohammadkhani
Abstract
Introduction
UCB-1 hybrid rootstock is propagated from the seed of a controlled cross between a P. atlantica female and a P. integerrima male. Clonal propagation of this rootstock is also necessary since it produces identical genotypes. UCB1 has recently been introduced in Iran. However, little ...
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Introduction
UCB-1 hybrid rootstock is propagated from the seed of a controlled cross between a P. atlantica female and a P. integerrima male. Clonal propagation of this rootstock is also necessary since it produces identical genotypes. UCB1 has recently been introduced in Iran. However, little research has been done on this subject. Water stress is one of the most important environmental stresses and occurs for several reasons, including low rainfall, high and low temperatures, salinity, and high intensity of light, among others. Drought stress is a multidimensional stress and causes changes in the physiological, morphological, biochemical, and molecular traits in plants. Proline is also found widely in plants and accumulates in large quantities in response to environmental stresses such as drought. It is the essential amino acids that accumulate in different tissues of the plant, especially in the leaves through the effect of water stress, and that the accumulation of it has a function in the regulation of osmosis in the cell as the proline is increased in the cytoplasm to counterbalance effort osmosis cell sap. Proline is an indicator of water stress tolerance and its increase in the leaf proof that the plant suffered drought stress, also is the way the plant tolerance to drought stress.
Materials and Methods
A pot experiment was conducted, to investigate the effectiveness of foliar applied proline in mitigating the concurrent effects of drought stresses on UCB1 rootstock, at greenhouse of Faculty of Agriculture, University of Shahrekord. Experiment was carried out in a completely randomized design with split arrangement having three replications. Chl. and carotenoid contents were determined according to Lichtenthaler (1987). Leaf discs were obtained from expanded leaves of each pot in the morning. The leaf discs were weighed immediately to obtain the fresh weight (FW), and submerged in distilled water for 4 h at 4◦C in dark condition and then weighed to prepare turgor weight (TW). The leaves were dried in a forced-air oven at 70◦C for 24 h, and the dry weight (DW) was recorded. The RWC of samples was calculated using the following equation (Bastam et al., 2012): RWC = [(FW–DW)/(TW–DW)] × 100
Levels of glycine betaine were quantified as described previously by Arakawa et al. (1990). To determine the free-proline concentration, leaves were homogenized in 5 ml of ethanol at 95%. Proline concentration was calculated with a standard curve and expressed as µg g−1fresh mass (Paquin and Lechasseur, 1979).
Results and Discussion
The UCB1 proximate analysis in the present study depicted that imposition of drought stress increased the leaf and root proline content and electrolyte leakage. Exogenous application of proline as foliar spray significantly increased the moisture content of leaf and root, RWC, Chl a and total chlorophyll. Exogenous proline application upregulated leaf and root proline contents and decreased the lipid peroxidation (decrease electrolyte leakage), resulting into improvement in chlorophyll contents. 150 mg. l-1 proline application gave maximum alleviation against stress.
Numerous reports depict that the exogenous application of proline as a foliar spray can play an important role in enhancing plant tolerance against drought stress, and our results are consistent with them. This ameliorating effect of exogenously applied proline can take the form of osmoprotection, cryoprotection, or protection against reactive oxygen species.For example, in various plant species growing under stress conditions, exogenously supplied proline provided osmoprotection and facilitated plant growth. Normally, proline accumulation in plants, is in response to drought or salinity stress occurs in the cytosol where it contributes substantially to the cytoplasmic osmotic adjustment. It actively takes part in plant osmotic adjustment under stressful environmental conditions. In addition to its role as an osmolyte for osmotic adjustment, it actively takes part to stabilize subcellular structures, biological membranes, proteins, and scavenge free radicals. It also plays a vital role in buffering cellular redox potential under stressful environmental conditions.
Conclusion
In summary, our results showed that, drought induces a decrease in moisture content, RWC, T Chl and carotenoids and an increase in some osmoregulators (proline, glycine betaine, TSC). The most favorable treatment was 150 mg.l-1 proline foliar spray. 150 mg.l-1 proline application gave maximum alleviation against stress. Foliar application increased the moisture content of leaf and root, as well as increased the Chl a, total, RWC and proline content of leaf and root. It can be suggested that the foliar application of proline (150 mg L-1) used as a plants defense factor against drought stress conditions.
Pomology
F. Karamnezhad; N. Moallemi; E. Khaleghi
Abstract
Introduction
Nitrogen plays an important role in the uniformity and quality of citrus trees. Several studies previously reported that a low level of nitrogen in citrus trees is generally caused a reduction in yield and fruit quality (Aziz, 1997; Khan et al., 2009). In this regard, applying urea is recommended ...
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Introduction
Nitrogen plays an important role in the uniformity and quality of citrus trees. Several studies previously reported that a low level of nitrogen in citrus trees is generally caused a reduction in yield and fruit quality (Aziz, 1997; Khan et al., 2009). In this regard, applying urea is recommended as the most suitable form of nitrogen for foliar application. The polyamines are included; putrescine, spermidine, and spermine which have been considered as plant growth regulators (Alcazar et al., 2010; Khezri et al., 2010). The role of nitrogen in vegetative and reproductive growth and yield, as well as the correlation between polyamines, flower induction and fruit set in other plants, were proved in previous studies. In this regard, the results of the current study will increase our understanding about the role of polyamines in the morphology of the tree and also the mechanism of regulating the alternate bearing of Kinnow mandarin leading to an approach method to address this problem.
Materials and Methods
To conduct this study a 17-year-old uniform of Kinnow Mandarin (Citrus reticulate Blanco) grafted onto Bitter orange (Citrus aurantium) rootstock, which grown in a commercial orchard, located in Dezful (Khuzestan Province in Iran). For sampling, the branches which possess leaves and nodes were selected from four sides of each tree, then leaves and nodes were collected at three different time points (one, three, and five weeks post-treatment). Samples were immediately frozen in liquid nitrogen after excision and transported to the Physiology Laboratory of fruit trees within 2h for determining the N fractions and polyamines. The concentration of N in dried leaves and nodes was determined using the colorimetry technique as described by Walling et al. (1989). The experiment was set up as a factorial treatment based on a randomized complete block design with three replications to investigate the effect of different concentrations of urea foliar application (0, 0.75%, 1.5%) on nitrogen and polyamines contents at different time points (Dec 22, Jan 5, Jan 20) followed by evaluating flower characteristics and yield in Kinnow mandarin plant. Data analysis including variance was carried out using MSTATC and SAS software. To compare the mean of polyamines and nitrogen in leaves and nodes, the cut-out method was used, and also for comparison of pistil dimensions, number of flowers, and yields, Duncan's multiple range test (DMRT) was performed.
Results and Discussion
Results indicated that polyamines concentration and nitrogen decreased during the period of time and also, in most cases, polyamines concentration was lower in the nodes than the leaves. High levels of polyamines and nitrogen were obtained in leaves and nodes which were treated with the foliar application of 1.5 % urea concentration after Jan 20. The polyamines content in leaves and nodes was greatly dependent on the spraying time and urea concentration used. Spermine (Spm) was the dominant polyamines in leaves and nodes with the highest values of 44.01 nmol/gF.W, 34.41 nmol/gF.W, respectively. Regarding the fact that flower density was higher in trees that treated with urea concentration of 1.5 % after Jan 5 y than other treatments, however, their yield was lower than the trees that treated on Dec 22 with the same urea concentration. This was probably due to the flower abscission as well as the fruit abscission in June. The results of this study showed that the highest yield was obtained with 1.5 % urea concentration after foliar application on Dec 22 compared with other treatments. Regarding the fact that flower differentiation in mandarin occurs during the late January until late February (in Dezful conditions), it can be explained that the foliar application on Dec 22 was performed before differentiation and consequently, the trees have received their required nitrogen. Also, the low-temperature is considered as natural inducer of citrus flowering in the Dezful, likewise, foliar fertilizer application in winter along with the natural factor (low temperature) stimulates flowering in a larger number of buds resulting in increasing the flowering. As nitrogen promotes vegetative and reproductive growth, it can be said that increasing the nitrogen content of leaves followed by transfering to the nodes, increases the number of buds, especially reproductive buds, which leads to an increase in flowering and yield. According to this study, the foliar application of urea in winter with 1.5% concentration can increase yield in Kinnow mandarin trees. Therefore, polyamines can play an important physiological role in flower development of Kinnow mandarin.
Conclusion
In this study, we focused on the effect of the foliar application urea during winter on leaves and nodes of Kinnow mandarin trees and investigated the polyamines, Put, Spm, and Spd contents upon treatments. In conclusion, the application of foliar urea in winter resulted in the significant endogenous increase of polyamines and N in the leaves and nodes of Kinnow mandarin trees. Also, yield, flower density, and pistil diameter were increased by spraying urea. There is a possibility that free polyamines affect on physiological processes.
