Exogenous Brassinolide Application Improves Growth, Yield and Quality of Strawberry Grown in the Subtropics

Strawberry cultivation is extending day by day from temperate to subtropical condition. But the yield and fruit quality is inferior in subtropics. Hence, an assessment was carried out to study the effect of brassinolide (BR) sprays on growth, yield and quality of strawberry under subtropics. BR at 0.1, 0.2 or 0.3 mg L-1 concentration was applied at the vegetative, flower initiation and fruit setting stage with different combinations. The experiment was laid out on a factorial randomized block design. Physiological growth (leaf area index and duration) were improved by three BR applications at vegetative, flower initiation and fruit setting stage together. The highest number of flower, fruit and marketable yield per plant (37.83, 33.00 and 402 g, respectively) were achieved by three BR sprays at 0.2 mg L-1 each with par result in 0.1 and 0.3 mg L-1 spray for three times. Three BR applications at 0.3 mg L-1 each had significant effect to increase fruit weight (18.3 g) with non-significant variation in 0.1 and 0.2 mg L-1 spray for three times. In addition, three BR applications at 0.3 mg L-1 also increased sugar and total soluble solids with non-significant difference in three sprays of BR at 0.1 or 0.2 mg L-1. Ascorbic acid and anthocyanin content were also recorded to be maximum in three BR applications with either concentration (0.1, 0.2 or 0.3 mg L-1). Therefore, after thorough economic analysis, it can be recommended that three BR applications at 0.1 mg L-1 each is optimum to improve fruit quality and yield of strawberry under subtropical conditions.