Effect of plant densities on morphological characteristics and seed yield of soybean genotypes in Markazi province

In order to study the effect of plant densities on morphological characteristics and seed yield of soybean cultivars in Markazi province an experiment was conducted in agricultural researches center of Arak in 2007. The experimental design was split plot arrangement in a randomized complete blocks design with three replications. The treatments included two factors, plant densities in four levels (16, 22, 28 and 34 plant/m2) as main plots and two soybean cultivars and line (Williams and L17) in subplots. Results showed that the effect of plant density on number of lateral stems, pods per plant and 1000 cernel weight was significant at 1% level. The effect of density on yield was significant at 5% level. Interaction of density cultivars was negligible on all studied traits except 1000 seed weight (at 1%) and grain yield (at 5%). Result also showed that the highest and lowest yield were obtained at D4 (34 plant/m2) and D1 (16 plant/m2) with 3880 and 3350 kg/ha respectively. The yield of L17 was 3980 kg/ha that higher than Williams with 3390 kg/ha grain yield. The highest yield was obtained with L17 at D4 density (4490 kg/ha) and the lowest yield was recorded with Williams cul in D1 density by 3010 kg/ ha. The D1 and D4 produced the highest (8) and lowest (3.3) lateral branches per plant respectively. The maximum number of pods per lateral branches was recorded at D1 and the minimum at D4, by 6.51 and 4.33 respectively. The highest (42.5) and the lowest (21.41) pods per plant was produced by D1 and D4 respectively. The average 1000 cernel weight at L17 was 152.42 gr. which higher than Williams with 147.42 gr. Maximum 1000 cernel weight was recorded in L17 at D1 density (160 gr) and the minimum 1000 cernel weight obtained with Williams cul. At D4 (136.3 gr) There were positive and significant correlation between grain yield and harvest index at 1% level and the number of pods per plant at 5% level.