Journal of Plant Process and Function

In order to study the effects of bio fertilizers and zinc application on yield, variations of quantum yield, stomatal conductance and some physiological traits of triticale under water withholding conditions, a factorial experiment was conducted based on randomized complete block design with three replications. Experimental factors were included water withholding in three levels (normal irrigation as control, irrigation withholding at 50% of heading stage, irrigation withholding at 50% of booting stage), four bio fertilizers levels (no bio fertilizer, application of mycorrhiza, Azotobacter chrocoocoum strain 5 + Psedomunas putida strain 186, application of PGPR and mycorrhiza together) and four nano zinc oxide levels (without nano zinc oxide as control, application of 0.3, 0.6 and 0.9 g L^-1). Results showed that under water withholding condition, photochemical efficiency of photosystem II, chlorophyll index, stomatal conductance, relative water content and grain yield decreased. Whereas, electrical conductivity and grain protein were increased. Means comparison showed that the highest of grain yield, photochemical efficiency of photosystem II, stomatal conductance, relative water content and chlorophyll index were obtained at application of PGPR+mycorrhiza, foliar application of 0.9 g L^-1 nano zinc oxide and full irrigation. The highest of grain protein was belonged at application of PGPR+mycorrhiza, foliar application of 0.9 g L^-1 nano zinc oxide and irrigation to 50% of booting stage. The highest of grain yield (663.26 g m^-2) was obtained at application of PGPR+mycorrhiza, foliar application of 0.9 g L^-1 nano zinc oxide and full irrigation and the lowest of it (198.46 g m^-2) was belonged at irrigation to 50% of booting stage, no biofertilizers and without nano zinc oxide. Irrigation withholding in heading and booting stages reduced 22% and 42% respectively from grain yield and using of biofertilizers and nano zinc oxide compensated 52% and 53% respectively from yield reduction. It seems that application of biofertilizers and nano zinc oxide due to the improvement of some physiological traits such as photochemical efficiency of photosystem II, chlorophyll content, stomatal conductance and relative water content can be recommended for profitable triticale production under water withholding condition.