EFFECT OF COMPOST AS ORGANIC FERTILIZER, NATURAL ROCKS AND SOME DIFFERENT BIOFERTILIZERS ON YIELD AND QUALITY OF FLAME SEEDLESS GRAPEVINES.

The present study was carried out during three successive seasons (2011, 2012 and 2013). (the first year was considered as a preliminary trial) on ten years old Flame seedless grape vines cultivated in a private vineyard at 64th kilometer Cairo-Alexandria desert road. The main of  study was to evaluate the effect of using organic fertilizer as compost in combination with or without two natural rocks ; Rock Phosphate and Feldspar. Also three different biofertilizers were used; Biogen (Azotobacter chroococcum) for N, Phosphorien (Bacillus Megathrium) for P and Potasiumag (Bacillus circulans) for K in comparison with the mineral fertilization , yield and its components as ( number of clusters per vine and cluster weight), physical and chemical characteristics of berries, and nitrite and nitrate content in berry juice of Flame seedless grapevine. The results revealed that using combined application of%100   compost, natural rocks and the three biofertilizers of NPK were very effective in increasing yield per vine and per feddan, cluster number per vine and weight, physical and chemical properties of berries were significantly improved. On the other side, Both nitrate and nitrite content in berry juice of Flame seedless grapevines were minimized comparing with the vines received 100% mineral fertilization or 100% compost alone. Furthermore, organic agriculture is very safe for human and environment by reducing pollution via improving soil nutritional status as well as decreasing mineral fertilization and that will be reflected on yield and quality of the grapes.