Browsing by Author "Aung, Louis Htin"
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- Developmental changes in nitrogen and protein of tall and dwarf tomato seedlings Lycopersicon esculentum MillBrumback, T. B. (Virginia Tech, 1976-03-18)Tris-soluble protein and total nitrogen of tall and dwarf tomato (Lycopersicon esculentum Mill.) seedlings were determined by the method of Lowry et al. and a modified micro-Kjeldahl direct Nesslerization technique. The tall tomato 'Fireball' differs from the dwarf 'Md. 412-4' in several ways: (1) the tall has more total nitrogen and protein; (2) it exhibits a significant increase in protein during the initial 48-hours of seeds imbibition; (3) it has a higher amount of protein in the roots; (4) the rate of decline of total nitrogen is faster than the dwarf, and (5) the tall tomato is more efficient in the utilization of plant nitrogen and protein. The greater growth of the tall resulted in a more rapid decline in nitrogen. However, in 10-18 day-old seedlings, growth was still rapid while nitrogen and protein did not change appreciably. The tall was more efficient and utilized a lesser amount of nitrogen and protein in the production of a comparable amount of fresh weight. It is suggested that the roots have considerable influence(s) on the growth of the shoot and that the decline in nitrogen and protein is a resultant of growth. It is indicated that the differences in growth may be more dependent on the manner in which nitrogen and protein are utilized rather than their absolute content.
- Growth hormones and their relationship to seed dormancy in QuercusDury, Carl George (Virginia Tech, 1977-11-05)Northern red oak (Q. rubra L.) seeds were dormant and required 10 weeks of moist, cold stratification before a large percentage of the seeds would germinate. White oak (Q. alba L.) seeds were not dormant and germinated immediately upon falling from the mother tree. A transfer of mass from the cotyledons to the embryos occurred during germination of red and white oak seeds. No detectable transfer of mass occurred during stratification of the red oak seeds. The longer the red oak seeds were kept under stratification conditions, the shorter the period of time required for seeds at 26°C to begin germination. A significant decrease in GA-like activity occurred during the first 5 weeks of stratification of red oak seeds. No transfer of activity from one pH-dependent ethyl acetate-soluble fraction to another occurred. A slight increase in GA-like activity occurred between 5 'and 7-1/2 weeks of stratification. Red oak seeds stratified for 18 weeks contained significantly more GA-like activity than those receiving lesser periods of stratification. When l8-week stratified red oak seeds were warmed to 26°C, germination commenced within 2 days and the levels of GA-like activity decreased. White oak seeds contained substantially less GA-like activity than red oak seeds and amounts of activity in white oak seeds changed little during cold storage of the seeds. Radicle extension growth of white oak seeds began even at 5°C and complete seed germination began within 2 days of warming to 26°C, independent of the time in cold storage. Cytokinin activity was measured in the ethyl acetate and n-butanol fractions of red oak seeds. Concentrations did not change between 0 and 5 weeks of stratification.
- Growth responses of crop plants to fish soluble nutrients fertilizationAung, Louis Htin; Flick, George J. Jr.; Buss, Glenn R.; Aycock, H. S.; Keefer, Robert F.; Singh, R.; Brandon, D. M.; Griffin, J. L.; Hovermale, Carl H., 1944-; Stutte, Charles A. (Virginia Agricultural Experiment Station, 1984)The utilization of fish wastes in the form of fish soluble nutrients (FSN) for agricultural crop plants fertilization was investigated over the past 7 years as an aid to the Virginia seafood industry threatened by the waste disposal problem. Controlled greenhouse and field experiments involving a broad selection of both food and nonfood crops have substantiated the ancient belief that fish and its byproducts have beneficial effects on plant growth. The investigations showed that FSN contains all the inorganic and organic substances needed for plant growth but does not provide a balanced source of nutrients for all crop species. By a proper selection of crop plant and fertilization with moderately dilute (4.0 to 16.0 ml FSN concentrate 1- 1 water) solutions, FSN have proven to be of benefit for the growing of several plants. Indoor crops grown in pots benefited more from FSN fertilization than did field-grown crops. FSN were found to retard reproductive development of plants and to delay plant aging. How F$N cause these growth processes is unknown and merit additional study.
- Tobit analysis of factors affecting vegetable expenditure patterns in U.S. householdsAung, Louis Htin (Virginia Agricultural Experiment Station, 1984-07)Household expenditure patterns were examined for vegetables in canned, fresh, and frozen forms and in five major subgroups. The source of data was the 1972-1974 U.S. Bureau of Labor Statistics Consumer Expenditure Diary Survey. Tobit analysis was employed to determine changes in the probability of vegetable purchases and changes in the magnitude of vegetable purchases as affected by household socioeconomic characteristics. The empirical analyses were based on information from 10,145 households. The list of characteristics hypothesized to affect vegetable expenditures included: (1) household income, (2) age-sex composition of the household, (3) region, (4) population density, (5) earner composition of the household, (6) education of the household manager, (7) race of the household head, and (8) food stamp participation. Household income, age-sex composition, population density, and region were the most important factors influencing expenditure patterns for vegetables. The remaining variates were statistically significant factors for only some vegetable subgroups and processed forms. Most important, except for total vegetables (the aggregate of all vegetable subgroups or processed forms), a change in any given socioeconomic characteristic was more likely to affect the number of households purchasing vegetables rather than the magnitudes of the purchases. Using this study, large numbers of socioeconomic profiles are constructed to examine household expenditure behavior and vegetables. Food marketers and industry analysts can use this information in planning location and format changes in food distribution outlets.