Evaluation of Yield, Rate and Effective Grain Filling Period of Maize Hybrids in Different Plant Densities

The yield of maize in Iran is very low as compared to other maize producing countries. One of the most important effective factors is non application of optimal plant population per hectare and maize hybrids differ in their response to plant density. In order to study the effect of different plant densities on yield, rate and effective grain filling period in maize hybrids, a factorial experiment based on randomized complete block design with three replications was conducted in 2007 at the Research Farm of the Faculty of Agriculture Mohaghegh Ardabili University. Experimental treatments were: maize hybrids in three levels (SC-404, DC-370, SC-504) with different plant densities (8, 10 and 12 plants.m-2). The results showed that yield and yield attributes characters (except of the number of grains rows) varied significantly due to the variation in population densities. The number of kernel per ear and number of grains per ear row increased with increasing plant density. The highest grain yield was obtained from 10 plant.m-2 density. Response of maize hybrids wasn’t the same for plant densities. The highest grain yield belonged to SC-504 hybrid and the least was in DC-370 hybrid. A two part linear model were used to quantifying the grain filling parameters. Cultivars and plant densities affected all grain filling parameters significantly. Maximum kernel weight, rate and effective grain filling period was obtained in low plant densities. Means of comparisons showed that maximum of kernel weight (0.35 mg) and effective grain filling period were obtained in SC-504 hybrid×8 plants.m2 and SC-404 hybrid×8 plants/m2. Minimum of it was obtained in DC-370 hybrid×12 plants/m2