Effect of irrigation systems, rates and polymer on water use efficiency, yield and Fruit quality of grape under desert conditions

: This experiment was carried out during the two successive seasons 2020 and 2021 on Flame Seedless grapevines grown in sandy soil under drip irrigation system at EL-Tahrir, El Beheira Governorate. The aim of this research was to save irrigation water without any reduction of water use efficiency, yield and Fruit quality of Flame Seedless grapevine under desert condition. In this experiment irrigation systems were applied as follow: T1 (control), T2 (surface drip irrigation with 25g polymer), T3 (surface drip irrigation with 50g polymer), T4 (subsurface drip irrigation without polymer), T5 (subsurface drip irrigation with 25g polymer), T6 (subsurface drip irrigation with 50g polymer), T7 (Oscop drip irrigation without polymer), T8 (Oscop drip irrigation with 25g polymer) and T9 (Oscop drip irrigation with 50 polymer). Beside three level of irrigation as follow W1 (100% of calculated applied water), W2 (75% of calculated applied water) and W3 (50% of calculated applied water). The obtained results cleared that: T9 under W2 resulted the best cluster weigh, total yield, length and width of cluster, weight and volume of 100 berries, soluble solids content (SSC), SSC/acidity and sugar contents in berries Juice. Also, T9 under W2 improve water use efficiency. On the other side, T9 under W2 gave the lowest total acidity in both seasons.