Effect of Tryptophan, Proline and Tyrosine on Vegetative Growth, Yield and Fruit Quality of Red Roumy grapevines

Document Type : Original Article


Viticulture Dept., Hort. Res. Inst., Agric. Res. Center, Giza, Egypt


This study was achieved out during two successive seasons (2018 & 2019) on 12 year-old Red Roumy grapevines.  The chosen vines were grown in a clay soil under surface irrigation system in a private vineyard at El-deer hamlet, Aga, Dakahlia region, Egypt. Three amino acids namely tryptophan, proline and tyrosine were used as foliar application at rate 100 and 200 ppm on the vines for three times, at vegetative growth start, at full bloom stage and at verison stage.  Results appeared that using tryptophan, proline and tyrosine were effective in improving shoot length, leaf area, total chlorophyll and total amino acids in the leaves  in addition percentages of N, P, K and Mg in the leaves as well as enhanced yield per vine, cluster weight, berry weight, berry set, SSC content, total sugars, total anthocyanin and total phenols, also enhanced pruning wood weight, ripening wood, internode length and thickness while reduced titratable acidity in berries as compared with control in two seasons. Application of tryptophan at 200 ppm and tyrosine at 200 ppm gave the significant highest of vegetative growth parameters, yield and its components. While, proline at 200 ppm increased SSC% and SSC acid ratio, total anthocyanin, total phenols and total sugars while these reduced titratable acidity. The best net profit of Red Roumy grapevines was obtained with tryptophan at 200 ppm.