Impact of foliar spray with 24-epibrassinolide on yield, quality, ripening physiology and productivity of the strawberry

Abstract

Increasing the productivity, yield and quality and modulating the ripening physiology of the fruit is considered as a main concern for the fruit growers. Brassinosteroids (BRs), as natural phytochemicals, are produced endogenously during fruit development and play a vital role in regulating its developmental, ripening and quality formation processes. In this study, the effects of different concentrations of exogenous 24-epibrassinolide (EBL), a common brassinosteroid, on ripening physiology, quality parameters and yield of strawberry fruit was studied. Foliar spray of strawberry plants and developing fruits with EBL significantly modulated the pattern and rate of fruit growth, decreased the fruit growth duration and enhanced the precocity rate. Visual indices such as size, shape and color of the fruits were significantly affected by EBL treatment. EBL at 1 μmol/L enhanced fruit growth rate and had no significant effect on the shape, but at 4 μmol/L significantly decreased the length/diameter ratio and resulted in the production of more spherical fruits with a very short growing period. However, a decrease in flesh firmness was observed in fruit treated with higher EBL concentration. EBL treatment significantly enhanced fruit weight, water content, total phenolics and anthocyanin contents and carbohydrate metabolism. The results indicate that the use of brassinosteroids can be considered as a novel method for modulating the growth pattern, yield and different quality parameters in strawberry fruits.