واكنش عملكرد دانه ارقام سويا و اجزاي آن بر تاخير در كاشت

The Response of Grain Yield and its Components in Soybean (Glycine max L.)Cultivars to Delay in Planting

In order to study the response of grain yield and its components in soybean cultivars for delaying planting time in Shirvan region, an experiment was conducted in 2002 at Research Field of the Faculty of Agriculture of Shirvan, Mashhad University. Iran. In this study nine soybean cultivars (habit, Hack, Blackhack. Cencutry, Columbus. Clark, Sahar. Zane and Willams)were planted on three (22 May, 6 June and 22 June) planting dates with factorial arrangement in randomized complete blocks. Nine traits were measured as: plant height, number of nods, number of secondary stems, number of pods per secondary stern, number of pods per plant, number of seeds per pod, number of seeds per plant, 100 seed weight and grain yield. The results indicated that grain yield and its components were significantly reduced by delayed planting. The first planting date (22 May) had the highest grain yield (2343 kg/ha). Reduction in grain yield at the second and third planting dates could be related to reduction in plant height, number of seeds per pod, number of seeds per plant and 100 seed weight .There were significant differences between soybean cultivars in grain yield and its components expect for number of pods per secondary stem, number of seeds j per pod and number of seeds per and plant. Lane cultivar had highest grain yield. Sahar cultivar had the lowest grain yield due to reduced number of seeds per pod and 100 seed weight and increased plant height, number of nods, number of secondary stem, number of pods per secondary stem. number of pods per plant, number of seeds per plant. Results showed that there was a significant positive correlation between Brian yield with number of nods, number of secondary stems, number of pods per plant and number of seeds per plant and I00 seed weight. The results also indicated that delay in planting causes reduction in grain yield. However, Zane, Blackhack, and Hack cultivars showed highest grain yield in all planting dates.