Effect of bio stimulant on growth and fruiting of Thompson seedless grapevines under heat stress condition

Shamrokh, A. A.; Al-Wasfy, M. M.; Abd El-Rahman, M.M.; El-Salhy, A. M.

doi:10.21608/svuijas.2025.391384.1478

Effect of bio stimulant on growth and fruiting of Thompson seedless grapevines under heat stress condition

Document Type : Original Article

Authors

¹ Department of Horticulture, Faculty of Agriculture, South Valley University, Qena, Egypt

² Pomology Department., Faculty of Agriculture, Assiut University, Assiut, Egypt

10.21608/svuijas.2025.391384.1478

Abstract

This study aimed to investigate the effect of root stimulator and foliar spraying with salicylic acid, citric acid, boron, amino acids and potassium silicate, on vegetative and fruiting of Thompson seedless grapevines under heat stress. The experiment was conducted during two successive seasons of 2022 and 2023. The experimental design is a complete randomized block design in split plot arrangement with three replicates, two grapevines each. Root stimulator was applied twice at growth start and after one month later. Citric acid and Salicylic acid at (1500) ppm, Boron at 500 ppm, amino acids at 2000ppm and potassium silicate at 3000ppm were foliar sprayed three times during growing season, first when new shoots reached 20 cm, after berry set and one month later. Application forms of root stimulator, as well as Boron, amino acids, potassium silicate, citric and salicylic acids significantly stimulated the vegetative growth traits and yield components compared to untreated ones (control). Moreover, they significantly improved the berry juice attributes, in terms of increasing total soluble solids (TSS) and sugar contents and decreased the total acidity. It could be concluded that root stimulator, salicylic acid, citric acid, boron, amino acids and potassium silicate application were useful in improvement of vegetative growth status and productivity of grapevines where that tolerate the harmful effects of heat stress.

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