Yield, growth, leaf nutrient content of guava (Psidum guajava L.)‎ as affected by different rates of nitrogen fertilization

الملخص EN

Five nitrogen rates, namely 0.0, 300, 600, 900 and 1200 g N per tree per year in the form of urea, were applied to nine-year-old guava (Psidum guajava.

L) trees grown under orchard conditions at El Rahad Agricultural Scheme in 1988 to study their effects on growth, leaf nutrient content and yield.

The amount of urea was split into two equal doses, half in April and half in August of 1988.

The results showed that all rates of nitrogen led to significant increase in tree height and trunk circumference than the control, throughout the experimental period.

Each increase in the rate of nitrogen showed an increase in height and in trunk circumference.

Significantly higher leaf-N content was detected in trees receiving different rates of nitrogen than the control.

Each increase in the rate of nitrogen resulted in an increase in the leaf-N content.

All rates of nitrogen had virtually no effect on leaf-P, K, Ca, Mg, Fe, Mn, Zn and Cu contents, regardless of the sampling date.

As the season advanced, leaf-N and Fe contents increased and leaf-P, K, Ca, Mg, Zn, Mn and Cu content tended to remain, more or less, constant.

Trees treated with different rates of nitrogen had significantly higher total yield than the control.

Appllication of 900 or 1200g N per tree per year resulted in significantly higher yield than the rest of the rates.

Each increase in the nitrogen rate produced an increase in the total yield