The Effects of Irrigation Regimes on Second Cropping of Three Soybean Genotypes in Moghan Region

To determine the effects of different irrigation regimes on second cropping of three soybean genotypes (Glycine max L.), an on farm split plot experiment based on randomized complete block design with 3 replications was carried out at Moghan Agricultural and Natural Resources Center during summer, 2010. The seeds were planted in a plot with 6 rows 60 cm wide, 250 cm length and plants 3 cm apart on the rows. The main plots comprised 4 irrigation regimes: I1=60 mm, I2=90 mm, I3 =120 mm and I4=150mm evaporation from class A pan) and sub-plots soybean genotypes (Williams, Linford and L17). The traits recorded were plant height, number of nodes, pods and seeds per plant, 1000 seeds weight, seed yield, height of first pod, number of empty pods, leaf number, lateral branches number (productive), pods length, inter-nodes distances, chlorophyll content, stem weight, pods weight, green leaf and roots weights. Analysis of variance of the data showed that there were significant differences among characters (like plant height, node number, pod number, inter node distance, pods weight, chlorophyll context volume and roots weight) and irrigation treatments The I1 treatment had the highest yield and node number, while the I4 treatment resulted in the least plant height and nodes number. Also I2 treatment produced the highest pods number while the treatments I4 resulted in the least pot number. Highest chlorophyll content was obtained under I4 treatment but under I2 treatment it was the least. The highest pod weight was obtained from I3 treatment and it was the least under the I4 treatment. The highest root weight was resulted from using I2 treatment and the lowest from I4. Also, ANOVA showed significant differences for plants height and inter nodes distances among genotypes (p