Effect of Spraying Sugar Alcohols and Amino Acids on Some Characteristics of Vegetative Growth and Yield of “Halwani” Grapevines

Abstract

Study conducted on Halwani grape vines to study the effect of spraying with sugar alcohol (mannitol) and amino acids at three concentrations of each (0, 5, and 10) ml L^-1 on some vegetative growth characteristics, yield, and quality, vines were sprayed three times during the season: the first spray at the beginning of vegetative growth, the second before the flowers bloomed, and the last spray after the fruit set. Spraying with 5 and 10 ml L^-1 of sugar alcohol significantly increased the leaf area of vines, leaf chlorophyll content, average number of clusters, and yield per hectare, total soluble solids and anthocyanin content of fruits. The acidity of berry decreased and the average weight of clusters, vine yield and total sugars significantly increased at a concentration of 10 ml L^-1, reached 0.308%, 529.87 g, 16.55 kg vine^-1 and 13.630%, respectively. While spraying with a concentration of 5 and 10 ml L^-1 of amino acid led to a significant increase in the leaf area of vines, average number and weight of the clusters, percentage of TSS and anthocyanin content of the fruits, the concentration of 5 and 10 ml L^-1 significantly affected the chlorophyll content of leaves, vine yield, yield per hectare and total sugar content in fruits, and the acidity content in fruits decreased significantly and reached 0.304% compared to the rest of the concentrations. The interaction between the study factors had a clear significant effect in improving the vegetative characteristics and the quantitative and qualitative qualities of the yield.