effect of salicylic acid priming on yield and yield components of cowpea (vigna unguiculata l.) under water deficit at reproductive stage

effects of seed priming by salicylic acid on yield and yield components of cowpea (vigna unguiculata) cultivar “parastou” were investigated under water deficit conditions. experiment was carried out as a split block design with three replications in 2008-2009 at research station of zanjan university. factors included drought stress as main factor with three levels (normal irrigation, application of water deficit at flowering and podding stages) and priming with salicylic acid as a sub factor with five levels (0, 900, 1800, 2700, 3600 µm). irrigation and salicylic acid had significant effects on yield and yield components. interaction between irrigation and salicylic acid was significant only for number of pods in stem, number of pods in branches, 100 seed weight, biomass and yield. mean comparison showed that yield and yield components decreased in water deficit compared to irrigated treatment. seed priming with salicylic acid increased pods length, number of pods, number of seeds, 100 seed weight, biomass, yield and harvest index in both irrigated and water deficit conditions. seed priming with 2700 µm salicylic acid increased yield and yield components compared to other treatments in irrigated and water deficit conditions where 4424, 3437 and 2475 kg.ha-1 yield achieved in regular irrigation, water stress at flowering stage and at podding stage, respectively.