Influence of Water Stress and Plant Density on some Characteristics in corn

Maize (Zea mays L.) production under the semiarid conditions of the Islamic Republic of Iran during the summer requires supplemental irrigation to attain maximum yields. Maize is cultivated in both spring and autumn seasons and it is best suited in existing cropping sche me. However, yield potential of maize is highly prone a biotic stresses. In maize, flowering is the most crucial stage in terms of negative effects of drought on yield. During this stage, one single day of drought can potentially decrease yield up to 8%. Plant populations affect most growth parameters of maize even under optimal growth conditions and therefore it is considered a major factor determining the degree of competition between plants. The field experiment was laid out spit plot design with factori al design with three replications. Treatments included cut irrigation (S1: Cut irrigation in 8 leaf, S2:Cut irrigation in 12 leaf, S3: Male flower appearance, S4: Normal irrigation) and density (6 plant/m 2 , 8 plant/m 2 , 12 plant/m 2 ). Analysis of variance showed that the effect of