Effect of plant density and chlormequat chloride (CCC) on morphological characteristics and grain yield of winter rape seed cv. Talayeh

Increasing plant density is often associated with lodging, hence decreasing photosynthesis efficiency and grain yield. A field experiment was conducted to evaluate the effect of three plant densities 30, 50 and 70 p/m2 and three different chlormequat chloride concentrations: 0, 1.4 and 2.8 l/ha on some morphological characteristics and grain yield of winter rape seed (cv.Talayeh). The study was conducted under Bajgah agroclimatic conditions in a silty clay loam soil, Shiraz, Iran. The experimental design was a randomized complete block with four replications. The results indicated that, increasing plant density from 30 to 70 p/m2 caused a significant increase in plant height (p <5%). When chlormequat chloride was applied at the rate of 1.4 l/ha at plant density of 70 p/m2 plant height was significantly decreased. Meanwhile the stem diameter and grain yield of plants treated with 2.8 l/ha chlormequat chloride at plant density of 70 p/m2 increased significantly. Although, the inter-nodes length and plant dry weight of the chlormequat -treated plants were smaller than control, their differences were not significant. It was conducted that under similar conditions to the present study, cv. Talayeh with plant density of 70 p/m2, and foliar application of chlormequat chloride at the rate of 2.8 l/ha can be used to achieve the highest grain yield.