THIS STUDY was carried out during two successive seasons ……(2014 & 2015) in a private vineyard at El-deer village, Aga, Dakahlia Governorate, Egypt. The experiment was conducted on 12-year-old Flame seedless grapevines cultivar. The vines were grown in clay soil under surface irrigation system, trained to quadrilateral cordon using Gable supporting system. Three amino acids namely Methionine, Glutamic acid and Argenine at a rate (500 ppm) were used as a spray application either alone or with Vitamin B1 (Thiamin) or Vitamin B2 (Riboflavin) at a rate (250 ppm) on the vines for three times at growth start (when shoots length reached about 40 - 50 cm), after fruit set and 2 weeks after fruit set as an attempts to improve growth, physical and chemical properties of Flame seedless grapevines.
The Results showed that single applications of amino acids or in combination with vitamins B1 or B2 were effective in improving shoot length, leaf surface 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 enhancing yield per vine, cluster weight, berry weight, soluble solids content, total sugars, total anthocyanin and total phenols while reducing total acidity in berries as compared with control in both seasons of study. In this respect, applications of amino acids plus vitamins were superior to using amino acids alone.
The best results with regard to vegetative growth, yield/vine, fruit quality and net profit of Flame seedless grapevines were obtained when vines were sprayed with Argenine plus vitamin B2.