The Effect of Different Levels of Pumice Mulch and Deficit Irrigation on the Some Physiological Traits and Seed Yield of Corn (Zea mays L.)

Mineral mulches, such as pumice, increase water retention of soil, reduce evaporation and optimum water consumption. Use of pumice, thus, can be effective in improving the performance and growth of plant under water stress condition. This research was performed in completely randomized block design with three replications, four levels pumice, without its use (as control), and use of 30, 60 and 90 tons of pumice per hectare and three levels of irrigation (at 50% severe stress, at 70% moderate stress and at 100% without stress, evaporation from class A evaporation pan to evaluate the effect of treatment on some physiological traits of corn (modified hybrid of Maxima). Physiological traits of corn, was affected significantly by pumice and irrigation. The highest and lowest chlorophyll index, leaf relative water content, stomatal conductance and dry and fresh weight biomass, were obtained from pumice treatment of 90 tons per hectare and the control. The highest and lowest leaf temperature was also obtained from treatments of control and 90 tons per hectare. Chlorophyll index of 90 tons treatment per hectare in comparison with control and 30 tons per hectare of pumice amounted to 52 and 26% respectively. Stomatal conductance of irrigation at 50% evaporation from evaporation pan in comparison with treatments 70 and 100% decreased by 42 and 23% respectively. Thus it can conducted that the use of the 60 tons per hectare of pumice and irrigation at 70% evaporation from evaporation pan would be effective and will significantly affect plant vegetative characteristics and yield of corn.