تاثير رژيم هاي آبياري و تراكم كاشت بر عملكرد، كارايي مصرف آب و كيفيت دانه سه رقم سويا در كشت تابستانه در شرايط آب و هوايي تهران

This study was conducted to evaluate the effects of four levels of irrigation (irrigation of plants after I, = 40, 12 =60, 13 = 80 , and 14 = 100mm of evaporation from class A pan) and four plant densities(D, = 30, D2 = 40, D3 = 50 and D4 = 60 plants/m2) on the seed yield and seed quality in three soybean cultivars(V,=Hobit, V2=Williams and V3=Hill) in a split factorial design, based on the completely randomized blocks, with three replication for two years(2001 and 2002). The Irrigation treatments were assigned to the main plots, and the plant densities and cultivars to the sub plots. Results indicated that soybean seed yield was influenced by the different irrigation and plant density levels in the bath years. Irrigation levels 12 produced the highest and 14 the lowest seed yield. It was also revealed that the plant density D3 produced the highest and D, the lowest seed yields. Among the cultivars under investigation, V2 produced the highest and V3 the lowest seed yield . Seed oil and its protein contents both were affected significantly by the irrigation levels, plant densities and cultivars in both years. The plants receiving I, treatment had the highest and those having 14, the lowest percentages of seed oil. Changes in the plant densities also affected seed oil and protein content. The plant density of D, caused the seeds to have the highest oil and lowest protein percentages. However, D4 decreased oil and increased protein percentages. The highest water use efficiency was obtained from I3 and that of the lowest value from I. The results also indicated that D4 had the highest and D, the lowest water use efficiencies. Therefore, it could be concluded that the water use efficiency can be increased by increasing the plant density per unit area. The highest efficiency for biological and grain yield belonged to V2 and Vi respectively where as the lowest efficiency for those two mentioned characters belonged to V, and V3, respectively. However, the treatment 12 V2D2 is recommended for higer the seed yield production per unit area.