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.
Niaz Gholi Firozbakht; Mehdi Rezaei
Abstract
Introduction: Size of fruit in Japanese plum has an important role in marketability and fruit quality. In Golestan province, one of the most important areas of plum production in Iran, due to high temperatures in summer that led to unfavorable conditions in fruit ripening stage, final fruit size are ...
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Introduction: Size of fruit in Japanese plum has an important role in marketability and fruit quality. In Golestan province, one of the most important areas of plum production in Iran, due to high temperatures in summer that led to unfavorable conditions in fruit ripening stage, final fruit size are reduced in commercial scale. In this respect, the large financial loss is imposed to plum growers. Today, synthetic auxins are widely applied in the commercial gardens of the world in order to increasing fruit size and improving fruit growth . Auxins can promotes cell division, cell enlargement in fruit growth stages and it also acts as sink for nutrients absorption. In this study, the effects of the foliar application of two synthetic auxins were investigated on fruit qualitative and quantitative of Japanese plums in Golestan province climatic conditions.
Material and Methods: A split-plot factorial experiment based on randomized complete block design with four replications was conducted in a commercial orchard from Run Agri Company in Golestan province, Iran for two years (2015 and 2016). The main factor was considered four plum cultivars including ‘Ghatreh Tala’, ‘Shablon Zodras’, ‘Shablon Mianras’ and ‘Shablon Dirras’ which were spraying by two synthetic auxins: NAA (0, 300 and 400 mg/l) and 2, 4-D (0, 10 and 30 mg/l) along and in combination. Fruit length, diameter, length to diameter ratio and fruit weight, yield, yield efficiency and percentage of first and second fruit grade production characteristics were evaluated. Data analysis was performed by SAS 9.1 software and the comparison of mean values was done by Duncan's multiple range tests at 0.05 of probability level.
Results and Discussion: The results showed that foliar application of auxin significantly increased fruit size and weight. The results showed that the response of plum cultivars to synthetic auxins was different. Fruit length and width of ‘Shablon Dirras’ cultivar were increased with the 2,4-D application at 10 and 30 mg/l , but in the ‘Shablon Mianras’ cultivar, the combination of 2,4-D with NAA improved fruit size. NAA at its highest concentration (400 mg/l) plus 2, 4-D at its highest concentration (30 mg/l) produced the largest fruits and the highest yield in ‘Shablon Mianras’ cultivar. Stern et al. (16) also obtained similar results from NAA and 2, 4-D treatments in plum, which is confirmed our results. The yield (kg/tree) and yield efficiency in plum cultivars increased significantly by synthetic auxin treatments. The average of yield (kg/tree) by 2, 4-D and NAA foliar application increased 30, 60, 28 and 34 percent in ‘Shablon Zodras’, ‘Shablon Mianras’, ‘Shablon Dirras’ and ‘GhatrehTala’ cultivars, respectively. The highest yield efficiency was obtained in ‘Shablon Mianras’ cultivar (0.38 kg/cm2) in 30 mg/L of 2, 4-D plus 400mg/L of NAA, which showed a 120 % increasing in comparison to control trees. Denis (7) reported increases the quantitative characteristics of stone fruits such as fruit size and weight by using synthetic auxin spray. The effect of auxin on increase cell proliferation and cell size are main reason for increasing the length and weight of the fruits (7). The results showed that 2, 4-D and NAA auxins were able to increase the percentage of first grade fruit relative in all plum cultivars in comparison to the control trees, but the concentrations and composition of plant growth regulators that increased the percentage of first grad fruits were not completely same to best treatments on fruit size, weight or yield. It referred to the first-grade fruits selection criteria. In selecting of best marketable fruits, in addition to the size of the fruit, others feature such as fruit appearance, color, physical damage and the absence of symptoms of diseases are also taken into grading. Temperature, water, nutritional and genetic conditions can affect the effect of plant growth regulator treatments (13).
Conclusions: Plum cultivars showed different reactions to synthetic auxin treatments. The largest fruit, highest yield and yield efficiency obtained in 2,4-D (30 mg/l ) with NAA (400 mg/l) in ‘Shablon Mianras’, ‘Shablon Dirras’ and ‘Ghatreh Tala’ cultivars and 2,4-D at 30 mg/l with NAA at 300 mg/l concentration in ‘Shablon Dirras’ and ‘Ghatreh Tala’ Cultivars. The highest degree of first grad-fruit was observed at 10 mg/l 2,4-D in ‘Shablon Zodras’ and ‘Dirrras’ cultivars and 300 mg/l of NAA in ‘Shabolon Mianras’ and ‘Ghatreh Tala’ cultivars.
