IMPROVING MINERAL UPTAKE AND PRODUCTIVITY OF SUPERIOR GRAPEVINES USING SOME STRAINS OF SOLUBILIZING POTASSIUM BACTERIA

Abstract

A laboratory experiment was conducted during 2015 and 2016 seasons to improve uptake and productivity of grapevines by producing three newly strains of solubilizing K bacteria (Histidineless, Argnineless and Phenylalanineless) by exposing the wild Streptomyces sp. with different doses of Ultraviolet irradiation from one to five minutes. These newly K strains as well as the slow release K fertilizer feldspar was used as a partial replacement of mineral K namely potassium sulphate (48% K2O). Supplying the vines with K as 50 to 75% mineral K plus feldspar as a slow release K fertilizer at 25 to 50% and any one of the three K bacterial strain each at 5 to 10 ml had an announced promotion on growth characteristics, pigments, N, P, K, Mg, Ca and S, berry setting (%), yield as well as physical and chemical characteristics of the berries relative to the application of K as mineral K alone. The best K strain was Histidineless followed by Phenylalanineless and strain Argnineless occupied the last position. The berries quality was remarkably enhanced due to supplying the vines with K as 50% mineral K + feldspar at 50% + Argnineless strain at 10 ml/vine. For promoting yield of superior grapevines, it is advised to supply the vines with K as 50% inorganic K plus 50% feldspar and Histidineless strain at 10 ml/vine. Supplying the vines with K as 25% mineral K + 75% feldspar + 20 ml (Argnineless strain) gave the best results with regard to berries quality.