Influence of Bud Load Levels and Fruit Unit Length on Growth, Productivity, Fruit Quality and Clusters Storability under Cold Storage of Midnight Beauty Grapevine

This study was conducted over two seasons (2022 and 2023) at a private vineyard in EL-Sadat city, Monofia Governorate. The chosen vines were 7 years old, planted in sandy soil, spaced at 2 x 3 meters apart, drip-irrigated, and trellised with a gable support. Vines were trained to quadrilateral cordon and spur pruned and clipped in the last week of December in both study seasons. Three different levels of pruning were used, namely (48, 72 and 96 nodes vine) under three different lengths of the nodes (2,4 and 6 nodes) with different number of fruiting spurs of Midnight Beauty Grapevine. Results show the number of clusters and yield per vine increased gradually as pruning per vine increased from 48 nodes per vine to 72 nodes per vine or 96 nodes per vine, while the physiochemical properties of clusters and berries gradually decreased. So, it can be recommended that pruning Midnight Beauty grapevine at 48 nodes/vine (24 spurs×2 nodes) gave the maximum values of bud behaviour, vegetative growth parameters, and berry physical and dormant season parameters, while vines pruned at 96 (48 spurs × 2 nodes) gave the highest yield per vine. All treatments have good quality under cold storage condition. The lowest significant percentage of fruit weight loss and decayed berries which recorded for 72 buds per vine with (18 spurs × 4 nodes). While clusters from vines pruned at 96 (48 spurs × 2 nodes) reduced shatter percentage and total titratable acidity with increasing in TSS.