Morpho-Physiological Responses of Maize to Drought Stress at Different Growth Stages in Northern Semi-Arid Region of Fars

In order to evaluate morpho-physiological responses of hybrid corn KSC750 to water stress at various stages of growth, a field experiment was conducted at the Pasargad region (northwest Fars) in 2010. The experiment carried out as a randomized complete block design, with 3 replications. In this study, corn growth period was divided into three phases: the establishment of plant to tasseling (phase I), tasseling to dough development (phase II) and dough development to ripening (phase III). Treatments were consisted of control, irrigation cut off after dough development, water stress of 75 percent of FC during vegetative phase and after dough development, water stress of 75 percent of FC during whole growth phase, water stress of 50 percent of FC during vegetative stage and after dough development and water stress of 50 percent of FC during whole growth phase. Results showed that mild drought stress (75% FC) at vegetative phase was not significantly effected growth and yield of corn. However, application of drought stress during the whole growth period significantly reduced morphological parameters as well as yield and yield components. Based on these results, flowering and grain filling stages were identified as more sensitive stages to drought stress in corn. Moreover, irrigation cut off after dough development terminated to a satisfactory yield. The results indicated that, overall, under Pasargad region and similar agro climatic conditions, it would be possible to save water to 75 percentage of corn water requirement through application of deficit irrigation after dough development stage.