Effect of salicylic acid on date bunch fading disorder

Abstract

Salicylic acid is a phenolic compound which could have an active role in the process of drought tolerance of plants. This study was conducted to investigate the effects of salicylic acid on date bunch fading disorder of Mazafati date cultivar, in a randomized complete block design with 5 levels of salicylic acid treatments' 0, 25, 50, 75 and 100ppm, at beginning of Khalal stage, in three replicates and two location of Bam region. In this study the percentage of damaged fruits caused by date bunch fading disorder, length of fruit, diameter of fruit, weight of fruit, pulp to seed ratio, yield, total soluble solids, pH, titratable acidity, percentage of total sugar, and percentage of protein were evaluated. Experimental date palm trees treated with 75ppm salicylic acid showed 45% reduction of damaged fruits caused by date bunch fading disorder in compare to other treatments at the 1% level of probability by Duncan's test. Furthermore, the application of 100ppm salicylic acid caused yield increase rate of 12kg per tree in compare to controls at the 1% level of probability by Duncan's test. Although some of salicylic acid treatments were effective in reduction of the damaged fruits caused by date bunch fading disorder and increase in yield of palm trees, but showed no significant effect on the physico-chemical characteristics of fruit. According to the biennium ANOVA table, some characteristics (length of fruit, weight of fruit, pulp to seed ratio, pH, total soluble solids, total sugar, percentage of protein, percentage of fruit moisture, and titratable acidity) did not show any significant differences, but the results of the classification by Duncan's test showed that spraying with salicylic acid solution in all treatments increased length of fruit, diameter of fruit, weight of fruit, pulp to seed ratio, yield, titratable acidity and pH, except for a reduction in the amount of total soluble solids and total sugar in compare to control.