STUDIES ON THE EFFECT OF POTASSIUM AND MAGNESIUM FERTILIZATION AS WELL AS VINE LOAD ON FLAME SEEDLESS GRAPE PRODUCTIVITY

This study was carried out during 2007 and 2008 seasons to study the effect of potassium and magnesium as soil fertilization under bud load of 40 or 60 eye/vine on bud behavior, yield and berry quality of Flame Seedless grapevines. Potassium was applied as potassium sulphate at two rates 150 and 300 g/vine and magnesium was applied as magnesium sulphate at 30 and 60 g/vine.
                Obtained data reveal that, both potassium and magnesium fertilization under 40 or 60 eye/vine increased bud burst and fertility percentages than the control. Furthermore, potassium fertilization at 300 g with 30 g magnesium sulphate per vine under leaving 40 eye/vine gave the highest bud burst percentage than those obtained under leaving 60 eye/vine. Also, potassium fertilization at 300 g with magnesium sulphate at 60 g/vine under leaving 60 eye/vine gave higher number of clusters and yield/vine than those obtained under leaving 40 eye/vine. Yet, potassium fertilization at 300 g with 30 g magnesium sulphate per vine under leaving 40 eye/vine gave higher cluster and berry weight, SSC, SSC/acid ratio and anthocyanin content than the other levels of potassium or magnesium fertilization under leaving 60 eye/vine.