Effect of different irrigation regimes, plastic mulch and anti-transpiration materials on some physiological attributes and grain yield of rainbow corn

In order to evaluate the effects of plastic mulch, kaolin and atrazine as anti-transpiration materials on some physiological attributes and grain yield of rainbow corn grown under different irrigation regimes, a two-year field experiment was carried out in Borazjan, Bushehr Province in 2016 and 2017 growing seasons. A randomized complete block design arranged in a split-split plot with three replications was employed to investigate the following experimental factors; irrigation regimes at three levels, (irrigation after 25 (no water deficit stress), 40 (mild water deficit stress) and 60% (severe water deficit stress) of field capacity (FC) water depletion), plastic mulch at two levels (with and without mulch) and anti-transpiration materials at three levels (kaolin, atrazine and no material). The results demonstrated that interaction between irrigation regimes and anti-transpiration materials was statistically significant on Fv/Fm ratio, and interaction between plastic mulch and anti-transpiration materials was significant on leaf soluble sugar content. At irrigation regime of 60% of FC water depletion, the highest Fv/Fm (0.578) was found when atrazine was applied, whereas the lowest value (0.468) was related to kaolin application. The obtained results suggest that in regions where water is a limiting factor, application of plastic mulch and atrazine wold improve crops quantitative and qualitative yield.