the effect of silicon application on grain yield of millet and water use efficiency under drought stress

the water deficit is the most important limiting non-biological factor to achieve the potential yield of crops. to evaluate the effect of silicon application on yield of millet under drought stress in field an experimental was carried out. treatments were included three irrigation regimes after 60 (non-stress), 90 (moderate stress) and 120 (severe stress) mm evaporation from evaporation pan, class a and four methods of silicon application including non-spray (control), spray, spray and using with irrigation water and using silicon with irrigation water in 2012 growing season in split plot based on randomized complete block design (rcdb) with three replications in hamedan. the results showed that the effect of drought stress and silicon on all traits, except water use efficiency under drought stress and number of grains per spike after silicon application were significant. the biological yield and grain yield were decreased by 15 and 22 percent in the moderate stress and 33 and 42 percent in the severe stress, respectively. interaction between drought and silicon application on 1000 seed weight, grain yield and water use efficiency were significant. the use of integrated silicon as spray and irrigation water had the highest positive effects on grain weight, water use efficiency, harvest index and benefit-cost ratio. economic analysis of different treatments showed higher benefit-cost ratio of all silicon applications. but maximum benefit-cost ratio was recorded from spray and using irrigation water. therefore, applications of silicon in combination of both methods are recommended.