Influence Different Level of Humic Acid and Irrigation Regime on Seed Yield and Morphological Traits of Corn under Warm and Dry Climate Condition

In order to evaluation effect of different level of humic acid affected drought stress on seed yield, its components and morphological traits of corn a research farm was conducted according split plot experiment based randomized complete blocks design at three replication during 2015 year. Main factor included four irrigation regimes (90mm, 110mm, 130mm and 150mm evaporation from pan class A) and four level of humic acid belonged to subfactor (non-application or control, 20, 30 and 40 L.ha-1). According result of analysis of variance effect of different irrigation regime and humic acid on all measured traits (instead number of row per ear) was significant but interaction effect of treatments was not significant. Mean comparison result indicated 90 mm evaporation treatment had highest amount of plant height (191 cm), leaf area index (4.1), ear diameter (8.1 cm), ear length (21.4 cm), number of row per ear (14), number of seed per row (40), seed weight (338 gr), seed yield (7120 kg.ha-1), biologic yield (1650 kg.ha-1) and harvest index (48.6 %), instead ear length loses. Also among different level of humic acid 40 L.ha-1 had similar trend and was superior in all measured traits. It should be noted that the amount of organic matter in the soil, type and texture of the soil can be effective on grades of stress, and for each climate and region, the level of water stress and the optimum amount of humic acid can be different. Finally according result of this research irrigation at 90 mm evaporation from pan class A led to achieve highest seed yield and with 40 L.ha-1 humic acid treatments can be advised for studied region.