MORPHO-PHISYOLOGICAL STUDY OF MAIZE UNDER NON-IRRIGATED WATER STRESS CONDITION

Abstract

In a laboratory experiment seeds of four maize varieties viz., BARI hybrid maize -5, BARI hybrid maize -2, BARI maize -7 and BARI maize -5 were germinated at 24, 30 and 36°C to study seed metabolic activity and seed reserve translocation. All of the four varieties were tested in the research field under well watered and non-irrigated water stress condition by seeding at 20 November, 2007 to evaluate the morpho-physiological changes in relation to water stress condition. Temperature had significant effect on germination characteristics and seed reserves mobilization. At moderate temperature (30°C) all the varieties showed highest seed metabolic efficiency (SME) than those of at 24 and 36°C temperature and hybrid varieties BARI hybrid maize -2 and BARI hybrid maize -5 attained higher SME than the BARI maize -5 and BARI maize -7. In phenology, the number of days for attaining different growth stages was affected by the interaction of growing conditions and varieties. In the non-irrigated water stress condition for all the varieties the number of days for attaining their seedling emergence, four-leaf stage, eight-leaf stage, twelve-leaf stage, tassel emergence stage, silking stage and maturity stage were higher than the well watered condition. The hybrid varieties required higher number of days for attaining those phenological stages compared to other varieties in both the growing conditions. Under well watered condition, all the varieties showed higher relative leaf water content (RLWC) and moisture retention capacity (MRC) compared to non-irrigated water stress condition. The combine effects of growing conditions (water level) and maize varieties differed significantly the number of green leaf at dry silk stage. length of leaf blade, length of leaf sheath, length of tassel, plant height, number of cob per plant, cob length, cob diameter, number of row per cob, grains per cob, single cob weight, weight of seed per cob, 100 seed weight, and grain yield. From the overall result it was observed that two hybrid varieties (BARI hybrid maize -2 and BARI hybrid maize -5) showed better performance in those physiomorphological traits compared to other varieties (BARI maize -5 and BARI maize -7) in both the growing conditions. Finally, from the drought susceptibility index (S) it might be concluded that BARI hybrid -2 and BARI hybrid maize -5 were comparatively drought tolerant (S<1) than the other varieties (BARI maize -5 and BARI maize -7).