Response of the vegetative growth, yield and nutrient contents of maize plants grown on a calcareous soil foliar sprayed with different phosphorus forms [electronic resource].

Includes reference.

This study was conducted to investigate the effect of foliar spray with different forms of P on some growth parameters, yield and nutrients status of maize plant grown on a calcareous soil. For this urpose, five P forms (dipotassium phosphate, monopotassium phosphate, diammonium phosphate, monoammonium phosphate and phosphoric acid) at two rates (2.5 and 5 g/L) were sprayed on maize leaves at 15, 30, 60 and 90 day after sowing. The recommended dose of super phosphate fertilizer as soil application was used as a base for comparison. The results showed that all treatments exhibited pronounced increases in the vegetative parameters i.e. plant height (em), stem diameter (em), ear grain weight (g), 100 grain weight (g) and dry weight (g/plant) as compared with the control treatment. The highest values of growth parameters were recorded for the treatment of monoammonium phosphate at 5 g/L, expect for ear grain, which showed highest value due to diammonium phosphate at a rate of 5 g/L. The greatest yield of straw, grains and harvest index were obtained for the treatments, monopotassium phosphate at a rate of 5 g/L, diammonium phosphate 2.5 g/L, monoammonium phosphate 5 g/L, respectively. The results also showed that all applied P forms increased the concentrations of N, P and K in both leaves and grains compared with the control treatment. The micronutrients Fe, Zn and Mn concentrations in straw and grains responded to the low rate of P foliar application than the high one. Also, results indicate that thetreatment with diammonium phosphate at a rate of 5 g/L recorded the highest values of N and P uptake by straw and grains, while the treatment with monopotassium phosphate at a rate of 5g/L recorded the highest values of K uptake. On the other hand, the treatments of monopotassium phosphate at a rate of 2.5 g/L, diammonium phosphate at a rate of 5 g/L and dipotassium phosphate at a rate of 5 g/L gave the highest values of Fe, Zn and Mn uptake by straw and grains, respectively. Generally, foliar spray with ammonium phosphate at both the two rates as di and mono ammonium phosphate resulted in the best maize parameters under the prevailing conditions of the current experiment.

Summary in Arabic.

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