Masters Theses

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Browsing Masters Theses by Department "Agronomy (Crop Physiology)"

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    The influence of temperature and defoliation on growth and carbohydrates of crownvetch (Coronilla varia L.) and some temperature responses of grass and legume seedlings
    Yadav, Uday Kumar (Virginia Polytechnic Institute, 1967)
    An experiment was conducted on crownvetch (Coronilla varia L.) to study the influence of various defoliations and three night-day temperature regimes (50-60, 70-80, 90-100 F) in controlled environmental chambers. Top and root growth and acid soluble carbohydrates in rhizomes and tops were studied. Night-day temperatures of 70-80 F produced highest dry matter yields which decreased with higher and lower temperatures. Increased temperatures decreased root growth and carbohydrates in rhizomes. Total available carbohydrates in tops were highest at mid and smallest at low and high temperatures. Frequent defoliations did not reduce the dry matter yields. A growth chamber experiment was also conducted to study the influence of three night-day temperature regimes (50-60, 70-80, 90-100 F) on emergence, survival and growth, and carbohydrates in roots and tops of several perennial legumes (alfalfa, red clover. and crownvetch) and grass (orchardgrass, tall fescue. and ryegrass) seedlings. The night-day temperatures of 70-80 F were most favorable for seedling emergence, survival, plant height, root weight, and dry matter production as compared with lower and higher temperatures. Alfalfa and red clover produced the most dry matter; whereas, alfalfa and orchardgrass were best in root growth ae compared with other species. Legumes accumulated more carbohydrates in roots and carbohydrates in tops of grasses were higher than in legumes. Carbohydrates in roots of legumes were similar at mid and high temperatures and lowest at 50-60 F; whereas, carbohydrates in tops of grasses were lowest at the two lower as compared with the highest temperature.