Wheat performance as affected by foliar application of molybdenum (Mo) under drought stress condition.

An experiment was conducted in order to evaluate the effects of Mo spraying on quantitative and qualitative characteristics of wheat grain yield under water stress condition, in Varamin agricultural resspikech center in 2011. A split plot layout within randomized complete block design with three replications was used. Main plots were three irrigation treatments (normal irrigation, non-irrigation at start of grain filling stage and non-irrigation at start of flowering stage) and sub plots were Mo spraying with three levels including spraying with pure water, Mo spraying with 0.5% concentration and Mo spraying with 1% concentration. The result showed that, grain yield and many of yield components affected by drought stress, significantly, on reproductive growth stage. Grain yield had significantly decreased by light and severe stress by 14.6% and 26.7% respectively. The most effect of stress at filling stage treatment were on thousand kernel weight leaf area duration and day to maturity, whereas, number grain per spike and number of fertile spike affected with stress at flowering stage treatment. Severe stress treatment had a significant effect on maximum amount of LAI and CGR. Leaf area duration decreased for both two stress treatments and leaf defoliation started so spikelier than normal treatment. Mo spraying has significant effects on grain yield and many yield components and also caused a significant decrease of water stress damages. 1% concentration of Mo spraying caused significant increase in total kernel weight, pedancle length, number of fertile spike and number of kernel per spike by 6.7%, 13.9%, 5.7%, 6.5% and 17.4% respectively. Day to maturity increased for 4 days in this treatment. Mo spraying with 1% concentration increased the grain yield from 5699 kg ha -1 to 6065 kg ha -1 significantly. There was no significant difference between to spraying concentrations (0.5% and 1%) for number of kernel per spike, total kernel weight, peduncle length, grain yield, biological yield, harvest index, protein yield and protein percentage. Also, the effect of Mo spraying was not significant for biological yield and harvest index. The manner of LAI and CGR changes during wheat growth period had significantly affected by Mo spraying. Protein percentage of wheat grain increased in both two irrigation and Mo spraying treatments.