Analysis of cotton photosynthate partitioning in diverse cotton genotypes, paraquat uptake by cotton, and supercritical fluid extraction method development /
(Gossypium hirsutum L.). A two-year field study compared the cultivars Tamcot CAMD-E (short-season) and Stoneville 213 (long-season). Partitioning of recent 14C-photosynthate from the uppermost, fully-expanded leaf on the main stem shifted from the main stem with its vegetative branches at the onse...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=737704461&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | (Gossypium hirsutum L.). A two-year field study compared the cultivars Tamcot CAMD-E (short-season) and Stoneville 213 (long-season). Partitioning of recent 14C-photosynthate from the uppermost, fully-expanded leaf on the main stem shifted from the main stem with its vegetative branches at the onset of reproductive growth to reproductive structures, especially the boll wall, during early reproductive growth. Nonstructural carbohydrates were preferentially partitioned to vegetative growth late in the season. Another two-year field study at three locations examined the effect of terpenoid aldehyde (TA) production on photosynthate partitioning. Eleven lines with high TA profiles and 3 cultivars that produced normal levels of TA were compared. The differences in biomass, dry matter partitioning, and yield between the high TA lines and the check cultivars were modest. These results indicate that crosses involving high TA lines and currently used cultivars should not reduce yield potential or change the pattern of dry matter partitioning in cotton. A third study examined the effect of drought on early season growth in long- and short-season cotton cultivars in a growth room. The long- and short-season cultivars responded similarly to drought. Shoot growth of these two cotton cultivars was more affected by drought than was root growth. Most importantly, tap root length was greater in the drought plants than in the control plants following drought and recovery periods. Two studies concerned agrochemicals. Cotton growers, using paraquat as a desiccant, noticed that dessication was influenced by the time of application during the day. Uptake of paraquat was examined in day and night applications. More paraquat was rinsed from the leaf of application in day treatments than in night treatments. Day-applied paraquat caused necrosis by 4 h; night-applied paraquat caused no symptoms. Thus, more paraquat entered the plant in the night than in the day. Another study compared supercritical fluid extraction (SFE) and solidphase extraction (SPE) to determine their effectiveness for the extraction of imidazolinone herbicides from soil. Three Texas soils were fortified with imazameth and imazethapyr. SFE recovery averaged 73.5% and was not consistent across soils. SPE recovery averaged 77.7% and was consistent. |
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| Item Description: | Vita. "Major Subject: Agronomy". |
| Physical Description: | xii, 83 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 75-82. |