Response of maize to phosphorus levels and plant density.

摘要

Two maize hybrids (Monsanto-707, Pioneer-3057) and an open-pollinated cv. Kisan-90 were planted under field conditions with three levels of phosphorus (60, 90, 120 kg ha-1) and three plant densities (70 000, 90 000, 110 000 plants ha-1) at NWFP Agricultural University Peshawar, Pakistan in 2002. The experiment was laid out in randomized complete block design with split plot arrangement with three replications. Combination of cultivars and phosphorus levels were allotted to the main plots while plant population to subplots. Maximum number of cobs plant-1 (1.36) and number of grains cob -1(556) were found in Pioneer-3057 hybrid while maximum 1000-grain weight (292 g) and grain yield (7269 kg ha-1) was obtained from Monsanto-707. Phosphorus levels also significantly affected cobs plant-1, 1000 grains weight and grain yield. Maximum cobs plant-1 (1.41), 1000-grains weight (276 g) and grain yield (6515 kg ha-1) were observed at the highest phosphorus level of 120 kg ha-1. Plant density also significantly affected cobs plant-1, grains cob-1, 1000-grain weight and grain yield. Maximum cob plant-1 (1.41) and 1000-grain weight (278 g) was noticed in plant density of 70 000 plants ha-1, while grain yield was highest (7269 kg ha-1) at plant density of 90 000 plant ha-1. Significant interactions between hybrid x phosphorus were found for 1000 grain weight and grain yield. Similarly phosphorus x plant density interacted significantly for cobs plant-1 and grain yield. It is concluded that Monsanto-707, phosphorus at the rate of 120 kg ha-1 and plant density of 90 000-plant ha-1 showed best performance..