الفهرس 
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Abstract
Among chemical and organic fertilizers tested the treatment of compost tea and chicken manure extracts at 1:10 concentration plus mineral N (20 N unit/feddan), P (40 P unit/feddan) and K (100 K unit/feddan) fertilizers (T8) along with that of the same component with organic fertilizers at 1:20 concentration (T9) were the super treatments to cause the most increasing effects on leaf area, leaf chlorophyll pigments, yield, cluster weight and volume along with berry physico-chemical characteristics. Moreover, the later treatment was succeeded to reduce nitrate contents berries as well as juice acidity percentage. These fertilizing programmes also were sufficient to meet N requirements of Thompson seedless grapevines grown in clay soil Furthermore, replacing N requirements by organic manure i.e compost tea and chicken manure extract is very useful for grape growers. In one hand, it save N fertilization cost by reducing N mineral fertilizer amounts applied on vines (from 60 N unit to 20 N unit/feddan) which are expensive compared to organic ones. This means that nearly 70 % of N- mineral fertilizers could be saved. On the other hand, the use of natural organic nutrients can be eliminate several troubles caused by application of chemical fertilizers, as it suppresses certain disease particularly those caused by fungal infections, maintaining and increasing the long term soil fertility through improving physico-chemical properties of soil and avoiding all forms of pollution. In the same line, the combined use of chemical and organic fertilizers can correct any deficit specially when the rate of nutrients release is not always match the needs of the vine.The recommendation by the combination treatment (T9) to be used as fertilizing program in Thompson seedless vineyards of clay soil because of its benefits which allows the treated vines to grow healthy and yielded an economic production quantity and quality save to consume and convenient for exportation. This in turn achieves an adequate income return and satisfaction from grapevine plantations. The interpretation of the income return/feddan saved through reducing N units added to grapevines/fed. from 60 N unit to 20 N unit/fed. equal 1022 L.E. the corresponding cost of applied organic nutrients combination (T9) 45 L.E. therefore, the net income return saved for feddan is 977L.E.