Effect of zinc foliar application on auxin and gibberellin hormones and catalase and superoxide dismutase enzyme activity of corn (Zea mays L) under water stress

To study the effects of zinc foliar application and water stress on quantitative and qualitative characteristics of corn, an experiment was conducted in Varamin, Iran during the growing season of 2011. The experimental design was randomized complete blocks in factorial arrangement with four replications. Factors included water stress (complete irrigation, irrigation after 90 mm of water evaporation and irrigation after 130 mm of water evaporation from class A pan) and the zinc foliar applications were as follows: 0, zinc sulfate and zinc chelate. Result showed that severe water stress decreased seed yield, oil percentage, chlorophyll content, relative water content, zinc grain content, auxin and gibberellin, and it caused an increase in antioxidant enzyme activity. Zinc foliar application increased all tested attributes under severe water stress. The results of these tests showed that zinc foliar application was effective against the detrimental effects of water stress

The effects of foliar application of ascorbic acid (vitamin C) on physiological and biochemical changes of corn (Zea mays L) under irrigation withholding in different growth stages

To study the effects of ascorbic acid foliar application and limited irrigation in different growth stages on physiological and biochemical changes of corn, an experiment was conducted in Varamin, Iran during the growing season of 2012. The experimental design was randomized complete blocks in split plots arrangement with three replications. Main plots included four different levels of irrigation (complete irrigation, irrigation withholding at 8-leaf stage, irrigation withholding at silks appearance stage and irrigation withholding at both 8-leaf stage and silks appearance stages) and different concentration of foliar application of ascorbic acid (vitamin C) (0, 75, and 150 ppm) were allocated to subplots. The results showed that irrigation withholding conditions in different growth stages significantly decreased seed yield, RWC and total chlorophyll but by contrast increased proline content, antioxidant enzymes activity. Ascorbic acid foliar application in irrigation with holding in different growth stages had positive effect on all attributes in this experiment. In general, the results of the present study indicate that usage of AsA reduces the harmful effects of water deficit stress and increases resistance to drought stress in corn plant

Effect of humic acid foliar application on growth and quantity of corn in irrigation withholding at different growth stages

In order to study effect of humic acid foliar application and limited irrigation on growth and quantitative character¬istics of corn an experiment was conducted in research field of Varamin in Iran during 2012 growing season. The experimental design was laid out in a randomized complete block with a split plots arrangement of treatments in three replications. Main plots included three different levels of irrigation (complete irrigation, irrigation withhold¬ing at 8-leaf stage and irrigation withholding at staminate inflorescence) and four different concentration of humic acid foliar application (0, 150,300 and 450 ppm) was allocated to subplots were. The results showed that irrigation withholding conditions in different growth stages significantly decreased plant height, yield components, seed yield, biological yield and harvest index. Humic acid foliar application in irrigation with holding in different growth stages had positive effect on all attributes in this experiment. In general, the results of the present study indicate that usage of humic acid reduces the harmful effects of water deficit stress and increases resistance to drought stress in corn plant