Yield of Pennisetum glaucum L. Under Phosphate Source Doses

Phosphorus deficiency has been a limiting factor in crop yields due to the low availability of this nutrient in the soil. Thus, the objective of this work was to evaluate the growth and P concentrations in plant tissue of two cultivars of forage millet grown submitted at doses of phosphorus (P). The experiment was set in greenhouse conditions in a Hapludox. The experiment was carried out in a completely randomized design in a 4 × 2 factorial scheme, with four replications, where the factors were the control treatment (without fertilization with P) and three levels of P (50, 100 and 200 kg ha-1) as simple superphosphate and two cultivars of pearl millet (BN2 and ADR500). The following were evaluated: plant height, stem diameter, dry matter of the aerial part (DMAP) and roots (DRM), phosphorus content in the leaf, in the stem and in the roots. The interaction between doses of P with the cultivars did not significantly affect the studied variables. Cultivar ADR500 provided greater height, stem diameter and dry matter of the aerial part. The best doses were 166 kg ha-1, 173 kg-1, 203 kg ha-1 and 165 kg of phosphorus ha-1 to height, stem diameter, DMAP, DMR and phosphorus content in the leaf, respectively. The increase of phosphorus rate increased content of P in the dry matter of the stem and roots on evaluated cultivars.