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PHYSIOLOGIC AND AGRONOMIC RESPONSES OF TROPICALLY AND TEMPERATELY ADAPTED GRAIN SORGHUM (SORGHUM BICOLOR (L.) MOENCH) HYBRIDS UNDER IRRIGATION AND NONIRRIGATION
Abstract
Two field experiments and one greenhouse experiment were conducted to compare the yield, yield components, and various morphological and physiological characteristics of tropically and temperately adapted hybrids in a temperate environment with and without irrigation. In the greenhouse experiment the water stress was imposed by withholding the watering at 50% anthesis stage for 9 days. During the 2 years of field experiments the tropically adapted sorghum hybrids were significantly taller than the temperately adapted hybrids. The tropically adapted hybrids showed a clear superiority for higher leaf area over the temperately adapted hybrids. In both years, the tropically adapted hybrids had 6% to 21% higher grain yields than temperately adapted hybrids both with and without irrigation. The seed numbers were the single main factor which contributed to higher grain yields. In the greenhouse experiment no significant differences were observed in leaf photosynthesis after 3 days of water stress. At 9 days after the water stress was imposed, leaf photosynthesis was severely inhibited. The response of the tropically adapted hybrid AT x 623 x 77CS3 was different than other hybrids and was found to be more stable. Severe water stress was very damaging at 50% anthesis. Portions of panicles were damaged from the tip down. However, on rewatering, the plants exerted partial panicles. A very drastic reduction in grain yield (as much as 56%) was observed mainly due to reduced seed numbers per plant. However, the seed weight compensated by a 15-31% increase. The stress at 50% anthesis was very detrimental and possibly interfered with the pollination or seed setting process, thus reducing seeds per panicle and grain yields. Among the hybrids, the tropically adapted hybrids showed consistently better grain yield both under the stress and nonstress conditions than temperately adapted hybrids.
Subject Area
Agronomy
Recommended Citation
SODHI, CHARANJIT SINGH, "PHYSIOLOGIC AND AGRONOMIC RESPONSES OF TROPICALLY AND TEMPERATELY ADAPTED GRAIN SORGHUM (SORGHUM BICOLOR (L.) MOENCH) HYBRIDS UNDER IRRIGATION AND NONIRRIGATION" (1982). ETD collection for University of Nebraska-Lincoln. AAI8227043.
https://digitalcommons.unl.edu/dissertations/AAI8227043