Application of Benzylaminopurine with Methyl Jasmonate and Epibrassinolide Improved Growth and Physio-biochemical Attributes of Strawberry ( Fragaria × ananassa cv. ‘Albion’)

Previous studies mainly focused on the effectiveness of benzylaminopurine (BAP) on the vegetative growth of the strawberry plant and the application of methyl jasmonate (MeJA) and epibrassinolide (EBR) at postharvest. Moreover, plant growth regulators (PGRs) have usually been sprayed on the whole plant, and the application of PGRs on different plant organs is rarely discussed in strawberries. Therefore, the effects of BAP, MeJA, and EBR as preharvest treatments on the strawberry fruits’ plant growth and quality indices of cv. ‘Albion’ was investigated. Also, MeJA and EBR leaf spraying with fruit spraying or their combinations were compared. Based on the results, leaf parameters and crown diameter were significantly affected by BAP. Treatment with 100 mg L −1 BAP followed by whole-plant spraying with 200 μM MeJA increased yield and produced greater fruit weight with the longest shelf-life. Also, regardless of the site of application, this treatment increased fruit number and the ratio of total soluble solids to titratable acidity, and enhanced total phenolic and flavonoid contents and phenylalanine ammonia-lyase (PAL) enzyme activity. MeJA at 200 µM improved ascorbic acid, total anthocyanin contents, and total antioxidant activity. EBR had no significant effect on the studied characteristics except fruit weight. BAP had beneficial effects on most of the traits at harvest. Preharvest whole-plant spraying of MeJA, a biosafe phytohormone, promisingly improved strawberries’ commercial and nutritional properties compared to EBR.