Nitrogen and Phosphate Fertilization of Hybrid Maize I. Response of ‘Texas-26’ to nitrogen and phosphate fertilization

The hybrid maize, Texas-26, gave strikingly positive response in yield, to applications of nitrogen under field conditions at the Institute farm. The magnitude of response was considerably higher under unfavourable growth conditions following excessive rains. A quadratic function could fully describe the grain yield response and the dose for the highest yield was thus predicated to be 107.5 kg N per ha in the first crop season (more or less normal growth season) and 161.3 kg N per ha in the second year (a season characterised by exceptionally high rainfall). Phosphate application indicated relatively less striking response. However, its importance was significantly evident, in supplementing the beneficial effects of nitrogen, particularly under unfavourable weather conditions. An application of phosphate at the rate of 89.6 kg P₂O₅ with 160.4 kg N per ha was found to be essential for the highest yield.