Effect of planting density on lodging and yield parameters in rice cultivars

In order to investigate the effect of planting arrangement on lodging and yield in rice cultivars, a split plot experiment based on randomized complete blocks design was conducted in four replications. The main plot was five rice cultivars (Tarom Mahalli, Tarom Hashemi, Tarom Deylamani, Tarom Langrudi and Sang Tarom) and three plant density (40, 80, 120 plant. M-2) were design as sub-plot. The lowest total spikelet’s and sterile spikelet’s were obtained in Tarom Langrudi and the lowest tiller number per hill and panicle number.m-2 were produced in Tarom Mahalli and Sang Tarom, respectively. Shortest length of first, second and third internode and biggest third internode diameter and also the least plant height were obtained in Tarom Langrudi. As a result the most lodging resistance and the least lodging index for third and fourth internode were produced in Tarom Langrudi. Total tiller numbers were decreased with increasing of plant density but in this case the panicles numbers were increased significantly. Node number, the length first, second internodes, the fourth internode diameter and also the third, fourth internode bending movement were decreased with increasing plant density. Minimum lodging index in the third and fourth internodes were produced in 80 plants per m2. Interaction of variety and planting density had significant effect on all agronomical traits and morphological characteristics that related to lodging traits. Therefore, there were significant differences between different rice cultivars in different planting arrangement.