Effects of molybdenum (Mo) spraying on morphophysiological characteristics of wheat under drought stress condition

In order to evaluate the effects of Mo spraying on quantitative and qualitative characteristics of wheat grain yield under water stress condition, an experiment was conducted in varamin agricultural research center in 2010 11. The experimental design was split plot in randomized complete block design with three replications. Main plots were three irrigation treatments: normal irrigation (S0), no irrigation at start of grain filling stage (S1) and no irrigation at start of flowering stage (2), and sub plots were Mo spraying with three levels including spraying with pure water (M0), Mo spraying with 0.5% concentration (1) and Mo spraying with 1% concentration (M2). The results showed that, grain yield and many of yield components significantly affected by drought stress, in reproductive growth stage. Grain yield significantly decreased in both S1 and S2 treatments by 14.6% and 26.7% respectively. Protein percentage significantly increased from 10.9% at S0 treatment to 11.8% and 13.4% for S1 and S2 treatments respectively. S2 treatment had a significant effect on maximum amount of LAI and CGR. Leaf defoliation in S2 treatment started so earlier than normal treatment. Mo spraying had significant effect on grain yield and many yield components and also had a significant lowering effect on water stress damages. The grain yield was significantly increased from 5699 to 6065 kg/hac in M2 treatment. There was no significant difference between two spraying concentrations (0.5% and 1%) for number of kernel per spike, number of fertile tiller, TKW, grain yield, biological yield, protein yield and protein percentage. Also, the effect of Mo spraying was not significant for biological yield. Protein percentage significantly increased from 11.4% in M0 treatment to 12.40% and 12.34% in M1 and M2 treatments respectively. The highest protein yield was obtained from S0M1and S0M2 with 735.8 and 724.8 kg/ha respectively. The manner of changes for LAI and CGR during wheat growth period had significantly affected by Mo spraying. The Maximum amount of LAI and CGR recorded in S0M1 treatment.