Hassan Sarikhani; Mohammad-Sadegh Safariyan-Nejad
Abstract
One of the most important problems of strawberry cultivation in temperate regions is winter cold injuries. Current study investigated impacts of foliar application of glycine betaine (GB) at 0, 0.5, 1, 2 and 4 mM concentrations on the cold hardiness of strawberry. The plants were divided into two groups: ...
Read More
One of the most important problems of strawberry cultivation in temperate regions is winter cold injuries. Current study investigated impacts of foliar application of glycine betaine (GB) at 0, 0.5, 1, 2 and 4 mM concentrations on the cold hardiness of strawberry. The plants were divided into two groups: one group for evaluation of cold hardiness at temperatures of -6, -9, -12, -15 and -18 °C; and the other for study of some biochemical characteristics. Results showed that GB treatment increased soluble carbohydrate and proline concentrations in both leaf and crown tissues, total protein concentration in leaf, and relative water content in leaf as compared to those in control. Based on LT50 calculated from electrolyte leakage and tetrazolium staining test, the GB application increased cold hardiness in strawberry plant based on its concentration. The highest cold hardiness was found in the 2 mM GB concentration based on electrolyte leakage and tetrazolium staining tests at -13.3 and -15.3 °C. Meanwhile, the lowest values of cold hardiness were observed in the control treatments based on electrolyte leakage and tetrazolium staining tests at -10.2 and -11.0 °C. Significant correlations were found between soluble carbohydrate and proline concentrations in leaf and crown, and total protein concentration with LT50 calculated from electrolyte leakage and tetrazolium staining test. We conclude that application of 2 mM GBhas the capacity to increase the freezing tolerance of strawberry and could be used as a prophylactic tool to reduce winter cold injury.
Tahereh Raiesi; Bijan Moradi; Javad Fatahi Moghadam
Abstract
Kiwifruit requires a high quantity of nutrients that must be supplied through fertilization to obtain an optimum yield on a sustainable basis. This research was conducted to evaluate different fertilization methods including broadcast application (as control), deep placement of the fertilizer and fertigation, ...
Read More
Kiwifruit requires a high quantity of nutrients that must be supplied through fertilization to obtain an optimum yield on a sustainable basis. This research was conducted to evaluate different fertilization methods including broadcast application (as control), deep placement of the fertilizer and fertigation, alone or in combination with foliar application and their effects on the yield, leaf mineral contents, and some quality properties of kiwifruit (A. deliciosa cv. Hayward). Results showed that fertilization methods had a significant effect on yield and the highest level of yield (76 Kg tree-1) was obtained in the combination of fertigation with foliar spray. In addition, foliar application significantly increased leaf mineral contents of kiwifruit in all treatments. Furthermore, the fertilization method had significant effects on phenol, ascorbic acid contents, and antioxidant capacity of fruits. The highest levels of antioxidant (70.9%), phenol (103.6 mg 100g-1), and ascorbic acid (54.2 mg 100 g-1) in fruits were recorded in ‘soil application’ method. Total soluble carbohydrate and starch contents of the fruits were reduced following foliar nutrition in all treatments. However, foliar nutrition significantly increased fruit crude protein. In conclusion, based on obtained results, fertilization method directly influenced the yield and leaf mineral status and indirectly influenced the fruit chemical composition of Hayward kiwifruit. In fact, the supplemental foliar application reduced some fruit quality attributes (lower antioxidant activity and carbohydrate content) but enhanced the yield of kiwifruit.
