Effect of Plant Density on Morphologic Characteristics Related to Lodging and Yield Components in Different Rice Varieties (Oriza Sativa L.)

In order to study the effects of plant density on agronomical and morphologic characteristics which are related to the lodging in rice varieties, an experiment was carried out in 2008 in split plot in randomized complete block design based on 4 replications in Iran. In this experiment, five rice varieties of Tarom (Local, Hashemi, Dilamani, Langhrodi and Sangh) were chosen as main factors and three plant density levels (40, 80, and 120 bushes per m²) as sub-factors. The results showed that Langhrodi Tarom had minimum total number of spikelets and number of hollow spikelets per panicle and minimum tiller per bush and number of panicles per m² had seen sequentially in Local Tarom and Sangh Tarom. The shortest length of first, second, and third inter-nodes, longest diagonal of the third inter-node and minimum plant height obtained for Langhrodi Tarom. Number of node and length of first, second and third inter-node and diagonal of the forth inter-node and Stem tension to lodging in third and forth inter-node decreased as plant density increased. Minimum lodging index of the third and forth inter-node came out at 80 bushes per m². Interaction effects in plant density had significant effects on all parameters except panicle number per m².