Improvingquality and Color of Flame Seedlessgrapes by Spraying (Abscisic, Ascorbic and Salicylic) Acids and Ethrel (Ethephon)

Abstract

This investigation carried out throughout two successive seasons 2016 and 2017, on six years-old Flame seedless grapevines in a private vineyard located at Km 93, Cairo, Alexandria desert road. Vines grown in sandy soil under drip irrigation system are trellised with Spanish (Paron) system and trained with quadrilateral cordon. The experiment included 10 treatments as follow:T1-Control (sprayed with water only), T2-Ethrel (ethephon) at 300 ppm, T3-Ascorbic acid (AA) at 500 ppm, T4 -Salicylic acid (SA) at 100 ppm, T5-ABA (Protone10% abscisic acid) at 400 ppm, T6-AA at 500 ppm + Ethrel (Eth) at 300 ppm, T7-SA at 100 ppm+ Eth at 300 ppm, T8-Eth at 300 ppm + ABA at 400 ppm, T9-AA at 500 ppm+ ABA at 400 ppm and T10-SA at 100 ppm+ ABA at 400 ppm. The foliar spray was used two times in the treatments from T2 to T5 but used once for every substance in the treatments from T6 to T10. The results cleared significantly effect of all treatments on yield, bunch, berry physical and chemical characteristics. Spraying with ascorbic acid (AA) or salicylic acid (SA) recorded highest values of 100-berry weight (g), berry firmness, attachment, berry length and width (cm) without significant differences with ABA in both seasons. The treatments of Ethrel (Eth), ABA and Eth+ ABA had maximum TSS (%), while Ethrel or Eth+ ABA had highest TSS/acid ratio and anthocyanin (%) in berries and also these treatments had least values of total acidity (%) in the two seasons. Spraying with ascorbic acid (AA) or salicylic acid (SA) or AA+ ABA or SA+ ABA recorded uppermost yield (kg/ vine) and bunch weight (g), followed by spraying Ethrel (Eth) or (Eth+ ABA).