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Accueil du site → Doctorat → États-Unis → 1981 → SOIL WATER, PLANT WATER, AND PLANT TEMPERATURE RELATIONS OF PEARL MILLET (PENNISETUM AMERICANUM (L.) LEEKE) GENOTYPES AND THEIR CORRELATIONS WITH CROP YIELDS

Texas A&M University (1981)

SOIL WATER, PLANT WATER, AND PLANT TEMPERATURE RELATIONS OF PEARL MILLET (PENNISETUM AMERICANUM (L.) LEEKE) GENOTYPES AND THEIR CORRELATIONS WITH CROP YIELDS

Singh, Piara

Titre : SOIL WATER, PLANT WATER, AND PLANT TEMPERATURE RELATIONS OF PEARL MILLET (PENNISETUM AMERICANUM (L.) LEEKE) GENOTYPES AND THEIR CORRELATIONS WITH CROP YIELDS

Auteur : Singh, Piara

Université de soutenance : Texas A&M University

Grade : Doctor of Philosophy (PhD) 1981

Résumé
The amount of research done on the response of pearl millet Pennisetum americanum (L.) Leeke to environmental stresses is presently insufficient. In 1979, pearl millet genotypes were grown under nonirrigated conditions. Whereas in 1980, they were grown under both irrigated and nonirrigated conditions. In another experiment in 1980, four pearl millet hybrids were grown under an irrigation gradient applied at all growth stages (IA), at 50% flowering only (IF), and at grain filling only (IG). In these experiments, observations were taken on water use and soil water depletion patterns, plant water status, leaf diffusion resistance, and plant temperature of genotypes. Statistically significant differences among genotypes were observed in various physiological responses, but the differences among genotypes in leaf diffusion resistance, canopy temperature, and canopy minus air temperature were relatively more significant and consistent. In both irrigated and nonirrigated environment, grain yield was negatively and significantly correlated across genotypes with their cumulative canopy temperature (SUMCT),(’ ) cumulative canopy minus air temperature (SUMCT-AT), and(’ ) cumulative leaf diffusion resistance (SUMLDR). Grain yield ratio (nonirrigated grain yield/irrigated grain yield) was negatively and significantly correlated across genotypes with SUMCT,(’ ) SUMCT-AT, and SUMLDR in the nonirrigated treatment. Whereas(’ ) grain yield ratio was positively and significantly correlated with SUMLDR and SUMCT-AT in the irrigated treatment. These results(’ ) indicate that when selecting for high yields and yield stability under well watered conditions, genotypes should have high SUMLDR or SUMCT ; but when the selection is done under a water-stressed(’ ) environment, genotypes should have low SUMLDR or SUMCT or(’ ) SUMCT-AT.(’ ) Majority of genotypes studied did not differ significantly in their total seasonal water use, water depletion from sub-soil, and water use efficiency for total dry matter and grain yield. In the irrigation gradient experiment, genotypic differences in grain yield and harvest index were statistically significant at wet and medium wet levels of irrigation, but they were nonsignificant at dry level of irrigation. Grain yield was significantly correlated across genotypes with their SUMCT in the main treatment IA, while(’ ) they were significantly correlated with SUMCT-AT in the main(’ ) treatments IF and IG.

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