AGRONOMIC STUDIES ON POTATOES (Solanum tuberosum L.)

The objectives of this investigation was aimed to study the effect of irrigation treatments, combination between mineral nitrogen and organic fertilizers on growth, yield and its components, quality, storability as well as chemical analysis of potato. From obtained results it could be concluded that maximum total tuber yield, marketable tuber yield/fed, and protein content in tubers were produced by irrigation tensiometer reading at 26cb and fertilization with 60% mineral nitrogen fertilizer plus 40 % organic poultry manure in both seasons. •Moreover, the highest values of water use efficiency (kg/m3) was recorded with irrigation at 34 cb and fertilization with 20% mineral N fertilizer plus 80 % poultry manure in the first seasons and fertilization with 60% mineral nitrogen fertilizer (99 Kg N/fed) plus 40 % poultry manure (66 Kg N/fed) in the second seasons. •Moreover, minimum total losses percentage, nitrate and nitrite concentration (ppm) in tuber were produced by irrigation at 34cb as well as application of 100 % organic poultry manure (165 Kg N/fed) in both seasons under the environmental of Dakahlia Governorate.