I- Effect of fertigation with nitrogen and potassium on vegetative growth, yield and leaf mineral content of "Washington" navel orange trees grown in sandy soils [electronic resource].

Includes references.

The present investigation was carried out during 2000 and 2001 seasons, in order to study the effect of fertigation with nitrogen and potassium on vegetative growth, fruit set, fruit drop, yield and leaf mineral content of "Washington" Navel orange trees grown in sandy soils. The main results can be summarized in the following points: 1. Average shoot length, leaf chlorophyll content, fruit set percentage, yield per tree, leaf N, K, Fe, Zn and Mn contents significantly increased with increasing drip irrigation, nitrogen and potassium fertilization rates, in both seasons. 2. Fruit drop percentage significantly decreased with increasing drip irrigation, nitrogen and potassium fertilization rates, in both seasons. 3. Increasing drip irrigation rate significantly increased leaf P, Ca and Mg contents, whereas increasing potassium fertilization rate significantly decreased leaf Ca and Mg contents. On the other hand, increasing nitrogen fertilization rate significantly decreased leaf P content, in both seasons.

Summary in Arabic.

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