effect of anti-transpirant and auxin on wheat (triticum aestivum l.) grain yield, yield-related traits, and germination

Objective: the grain yield of wheat is always limited by drought in arid and semiarid areas. field and laboratory experiments were conducted to investigate the effects of anti-transpirants and auxins on grain yield, yield-related traits, and germination of wheat.methods: the field experiment was carried out in the chamchamal plain of kermanshah, iran, using a split-plot design with three replications. concentrations of auxin (0, 50, and 100 ppm) were arranged in main plots, and anti-transpirant (sunflower oil) concentrations (0, 5, and 10%) in subplots. 2,4-d + mcpa (2-methyl-4-chlorophenoxyacetic acid) were used as auxins. at the harvesting time (june 20, 2014), several agronomic characteristics, including grain yield and single-grain weight, were measured. in addition, a laboratory experiment was conducted by choosing random seeds from the mother plants in the field experiment to study the effect of anti-transpirant and auxin on germination characteristics, including germination percentage, caulicle length, and radicle length.results: results showed that auxin application of 100 ppm had the lowest single-grain weight. anti-transpirant and auxin application had no significant effect on grain yield. auxin concentration of 100 ppm with an anti-transpirant application rate of 0%, and an auxin application rate of 100 ppm with an anti-transpirant concentration of 10% resulted in the lowest harvest index.  also, the auxin concentration of 100 ppm with an anti-transpirant application rate of 10% had the lowest seed germination. this is probably because hormonal and oil agents have mediated the increase in wheat seed germination inhibitors.conclusion: using auxin and anti-transpirant in the reproductive stage didn’t have a positive effect on grain yield, yield-related traits, and germination of seeds from mother plants in wheat. also, auxin had a negative effect on the single-grain weight. therefore, the studies about the effect of herbal anti-transpirants and auxin at the vegetative stage of wheat are recommended to gain further insight about the effectiveness of these compounds on agronomic traits in wheat.