Effect of Varying Levels of Nitrogen and Potash on Vine Growth, Fruit Yield and Quality in Thompson Seedless Grape (Vitis V1Nifera L.)*

With an aim to determine the optimum doses of N and K₂O for the mature vines of Thompson Seedless grape grown on red sandy-loam soils belonging to "Udic palenstalf" group based on long term experimentation, a field trial with four levels each of N (300, 600, 900 and 1200 kg/ha/year) and K₂0 (0, 500, 1000 and 1500 kg/ha/year) was carried out during 1981–1984, at the Indian Institute of Horticultural Research. Nitrogen levels influenced the prunings weight, cane number, yield and bunch number/vine and T. S. S. content of the juice, while the potash levels influenced the yield and bunch number/vine significantly. Interaction effect of the levels of N and K₂O was not significant on any of the yield or quality parameters. Considering the effects on yield and quality, a combination of 300 kg N and 1000 kg K₂O/ha/year was concluded to be optimum.