This investigation was conducted during two successive seasons 2016 and 2017 on ten years old mango (Mangifera indica L.), cv. Ewaise cultivar trees grown in Idku Center (Sand Basin No. 1) El-Behaira Governorate, Egypt. Ewaise mango trees grafted on Zebda seedlings grown at a distance of 6 x 4 m to study the effect of organic and mineral fertilization on yield and fruit quality of Ewaise mango cultivar. The experiment consisted of 8 treatments arranged in a randomized complete block design with 5 replicates for each treatments and one tree for each replicate. 1-Control 100% NPK, 2-50% NPK+ 100% plant compost (P.C), 3-50% NPK+ 100% animal compost (A.C.), 4-100% (P.C.), 5-100% (A.C), 6-50% P.C. + 50 % A.C., 7-50% (NPK+ P.C. + A.C.) 8-100% (NPK+ P.C. + A.C.). Results revealed that, 100% of (NPK+ P.C. + A.C.) followed by 50% (NPK+ P.C. + A.C.) gave the highest mean values of number of fruit/tree and yield/tree as compared to other treatments and control, also, gave the maximum values of fruit physical characteristics: fruit weight (g/ fruit), fruit length (cm), fruit diameter (cm), fruit volume (cm 3 ) and pulp%. On the other hand, 100% of (NPK+ P.C. + A.C.) followed by 50% (NPK+ P.C. + A.C.) gave the higher fruit chemical characteristics total sugar %, reducing sugar %, non-reducing sugar %, vitamin C (m g/ 100 ml juice), total acidity (%), TSS (%) and nitrogen, phosphorus and potassium % in leaves and fruits as compared with the control and other treatments, during both seasons, respectively.

The growth of maize (Zea mays L. cv hybrid 2031) plants were evaluated under water stress induced by decreasing soil moisture from 80% of field capacity as optimal value (control )to 40%, 50%, 60% and 70% of FC treatments, being considered as water stress for maize as affected by Si application at five rates (0. 50. 100, 150 and 200mg Si kg -1 soil). This evaluation was carried out in a pot experiment using calcareous soil in a split plot design. The soil moisture levels were applied to the main plots and the silicon levels were assigned to the sub-plots. The results obtained showed that water stress depressed the growth of shoot, relative water content and chlorophyll index values. Addition of Si up to 200 mg kg -1 soil partially improve the growth of shoot and increase the relative water content, chlorophyll index and proline content. The proline content in the leaves was markedly increased under water stress or with silicon application especially under high water stress conditions. The negative relationship between proline content and shoot dry weight, supporting the view that proline accumulation is a symptom of stress damage. Addition of Si increased Si accumulation in the shoot. Analyses of N, P, K, Cu and Zn showed no accumulation of these elements in the shoot under water stress, and added Si even increased their concentrations under water stress. These results suggest that under water stress conditions, silicon nutrition can improves maize plant growth.