Response of yield and some physiological traits of rainbow maize to plastic mulch, anti-transpiration materials and irrigation regimes

The effects of plastic mulch, anti-transpiration materials and irrigation regimes were evaluated on ear yield and some physiological traits of rainbow maize. The experiment was carried out in Borazjan located in Bushehr Province, Iran, during 2016 and 2017 growing seasons. The experimental design was split-split plots in randomized complete block design with three replications. The main factor of the experiment was irrigation regimes at three levels including: 1) Irrigation after 25% water depletion of field capacity (no water deficit stress), 2) Irrigation after 40% water depletion of field capacity (mild water deficit stress) and 3) Irrigation after 60% water depletion of field capacity (severe water deficit stress), sub-factor at two levels including plastic mulch and without mulch and sub-sub-factor at three levels including kaolin and atrazine anti-transpiration materials and control treatment (without anti-transpiration materials). The results showed that the interaction of irrigation regimes, plastic mulch and anti-transpiration materials was significant on ear yield. At irrigation regime of 25% water depletion, the highest ear yield (1759.8 g.m-2) was found when soil surface was covered with plastic mulch and plants were sprayed with atrazine. On the other hand, the minimum ear yield (1165.7 g.m-2) was obtained when soil surface uncovered and no anti-transpiration materials were applied. With decreasing soil water, atrazine application increased fresh ear yield more than kaolin. Under severe water deficit stress condition (60% water depletion), chlorophyll and protein contents of leaves decreased. In total, the results of this research showed that application of plastic mulch and atrazine anti-transpiration are recommended to produce the highest quantitative and qualitative yield in rainbow maize in regions where water is the main limiting factor.