Shima Chayani; Ahmad Ershadi; Hasan Sarikhani
Abstract
Delaying bud break, using chemicals is an approach to avoid spring frost damage. Therefore, the effect of spraying different concentrations of soybean oil and naphthalene acetic acid (NAA) on delaying bud break, altering internal atmosphere and cold hardiness in grape cultivar ‘Fakhri’ was ...
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Delaying bud break, using chemicals is an approach to avoid spring frost damage. Therefore, the effect of spraying different concentrations of soybean oil and naphthalene acetic acid (NAA) on delaying bud break, altering internal atmosphere and cold hardiness in grape cultivar ‘Fakhri’ was studied in 2011 in a commercial vineyard in Maryanaj, Hamedan using a factorial trial based on randomized complete block design with three replications. Selected branches were pruned to six buds. The concentration of carbon dioxide and ethylene gases in the buds were measured three days after spraying. Results showed that spraying 10 percent soybean oil alone or in combination with 100 mg/l naphthalene acetic acid caused the highest concentration of carbon dioxide and ethylene in buds, delayed bud bursting for 12 days and improved cold resistance of buds by 5°C. Auxin had minor impact on delaying opening and increasing cold tolerance of buds, while five percent soybean oil alone or in combination with NAA had intermediate effect. Applying oil treatments in March had more considerable effect on delaying bud opening and CO2 and ethylene accumulation, compared to April spraying. It seems that applying soybean oil prolongs bud dormancy due to increasing respiratory gases accumulation which subsequently delays bud break and resulted in decreased spring frost damage.
Omidali Ghasem beigi; Javad Erfani Mogadam; Orang Khademi
Abstract
In the current study, for improving quality and quantity of ‘Yaghooti’ seedless grape, gibberellic acid was sprayed in four concentrations including zero (as control), 15, 25 and 40 mg/l, at three stages, and girdling treatments were carried out simultaneously with the third step of GA3 spraying ...
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In the current study, for improving quality and quantity of ‘Yaghooti’ seedless grape, gibberellic acid was sprayed in four concentrations including zero (as control), 15, 25 and 40 mg/l, at three stages, and girdling treatments were carried out simultaneously with the third step of GA3 spraying at the base of fruit bearing shoots with four replications. The cluster length was significantly increased by all three concentrations of GA3 in compare with the control. In fact, 14 days after GA3 spray, the cluster length respectively grew to 17.87, 19.73 and 23.95 cm at 15, 25 and 40 mg/L GA3, whereas, in the control sample it was 13.46 cm. Furthermore, the berry and cluster weight were increased by foliar application of GA3 and girdling in which the maximum berry weight (1.42 gr) and cluster weight (483.7 gr) were achieved by interaction of 40 mg/l GA3 and girdling. In addition, girdling treatment significantly led to the increase of the berry length and width as compared to control sample; however, for some traits there was not any meaningful treatment. Application of GA3 and girdling treatment significantly led to the increase of the TSS/TA ratio in compared to control.
Ahmad Ershadi; Samira Taheri
Abstract
Frost in early spring is one of the limiting factors in the production of grape. Chemicals offer useful approach to reduce low temperature-induced damages. Different concentrations of salicylic acid including: 0 (control), 0.5, 1 and 2 mM were sprayed twice on 10 year-old ‘Bidaneh Sefid’ ...
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Frost in early spring is one of the limiting factors in the production of grape. Chemicals offer useful approach to reduce low temperature-induced damages. Different concentrations of salicylic acid including: 0 (control), 0.5, 1 and 2 mM were sprayed twice on 10 year-old ‘Bidaneh Sefid’ grape vines at full bloom stage and changes in leaf soluble carbohydrates, proline and protein levels were measured in the next day morning. Leaf and stem samples were subjected to low temperatures of 0, -2, -4 and -8°C while flower clusters were exposed to temperature of 0, -2 and -4°C for three hours. Salicylic acid at 0.5mM concentration resulted in the highest amounts of soluble carbohydrates while the maximum proline content was observed with 0.5 and 1mM concentrations. Salicylic acid at 2mM concentration caused a decrease in soluble protein level. Salicylic acid, low temperature and their interactions had a significant effect on electrolyte leakage of different tissues. Salicylic acid treatments led to a reduction in electrolyte leakage of stem, leaf and cluster samples, compared to control. It seems that salicylic acid minimizes the negative effects of low temperature with evidence of less membrane damage by up-regulating the accumulation of osmoregulants such as soluble carbohydrates and proline.
Farnaz Ahmadi; Abdolrahman Mohammadkhani
Abstract
Optimal nutrition of grapevine is one of the most important factors that affect the quantity, quality and time of fruit ripening. To increase the quantity and quality of ‘Askari’ cultivar, a factorial experiment in a randomized complete block design with three replications was conducted at ...
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Optimal nutrition of grapevine is one of the most important factors that affect the quantity, quality and time of fruit ripening. To increase the quantity and quality of ‘Askari’ cultivar, a factorial experiment in a randomized complete block design with three replications was conducted at Shahrekord in 2010. Treatments consisted of four levels of potassium sulfate fertilizer (zero, 300, 600 and 900 g per vine) and four levels of boric acid fertilizer (zero, 1000, 2000, and 3000 ppm). The results showed that potassium had a significant effect on yield and yield components. Different levels of potassium sulfate and boric acid increased cluster (number, weight, length, width) and fruit soluble solids. With increasing potassium levels, the number of clusters (14, 18 and 25) and content of total soluble solid (0.54, 1.45 and 1.53 percent) were significantly increased in comparison with control, respectively. Also, total soluble solids of berries were increased significantly (0.76, 0.75 and 1.25 percent) with boron treatment compared to control. The highest TSS (18.8) obtained in 900 mg of potassium sulfate per square meter, while it caused the greatest reduction in fruit acidity compared with the control. Fruits pH was decreased by 0.3 units with application of 3000 ppm of boric acid. The results of this experiment showed that nutrient treatments, especially potassium sulfate accelerated fruit ripening and increased fruit yield and sugar content.