Effect of Water Stress and some Anti - Transpirants on Growth, Yield and Quality of Okra Plants (Abelmoschus esculentus)

Two field experiments were conducted at private farm in Belqas, Dakahlia Governorate, Egypt during the two summer seasons of 2016 and 2017 to study the effect of irrigation intervals and foliar application of different antitranspirants i.e., silicone in from of potassium silicate K2SiO3 (1000 ppm), chitosan (150 ppm) and glycine betaine (700 ppm) and their interactions on vegetative growth characters, pod yield, quality traits and chemical constituents of okra (Balady cultivar). The results showed that short irrigation intervals (10days) significantly increased number of leaves/plant, fresh and dry weight (g) as well as leaf area/plant, pod yield/plant, total pod yield (ton/feddan), pod length, chlorophylls a, b, total chlorophyll and chlorophyll a/b ratio of okra leaves and vitamin C, carbohydrate, protein, total sugars contents of okra pods compared with (irrigation at 20 days), except total soluble solids (TSS %) which had the highest significant values at 20 days irrigation intervals compared with 10 days irrigation intervals. Spraying with all foliar applications led to significant increase all the studied parameters compared with control treatment in both seasons. The superior application was chitosan in particular 150 ppm followed by glycine betaine followed by silicon while control treatment recoded the lowest values in both seasons, respectively, glycine betaine in particular 700 ppm  gave the highest values of TSS of okra pods followed by chitosan followed by silicon while control treatment recoded the lowest value. From the obtained results, it could be concluded that Balady cultivar of okra plant which irrigated at 10 days interval and sprayed with chitosan at 150 ppm four times, i.e., 20 days after sowing and repeated each 10 days interval, respectively recorded the highest values of all studied traits of okra plant compared to other treatments, except Total soluble solids (TSS %) which had the highest significant values of okra pods with the interaction between (irrigation every 20 days interval × foliar sprayed by 700 ppm of glycine betaine) during both seasons.