Cotton (Gossypium hirsutum L.) is a perennial plant managed as an annual crop to optimize yield and fiber quality while managing inputs to maximize profit. Transgenic improvements have simplified cotton production. Resistance to the non-selective herbicide glyphosate and in-plant production of Bacillus thuringiensis (Bt) endotoxin are two such advances. Cultural practices including use of mepiquat chloride (MC), and optimizing planting date contribute to crop uniformity and decrease risk involved with environmental stresses. Comparisons between conventional and transgenic weed and insect management systems, optimal and late planting dates, overhead sprinkle irrigation and drip irrigation, and use of MC were evaluated. Optimal-planted cotton had better yield than cotton planted late. Mepiquat chloride did not always provide an advantage, however never caused an undesirable response. At times, cotton plants treated with MC showed improved micronaire, compensation for boll loss, and earlier maturity. Broadcast glyphosate at the eight-leaf stage reduced yield of optimal-planted cotton in 1 of 3 years and 2 of 3 years in late-planted cotton. Glyphosate contact after the four-leaf stage in 2 of 3 years shifted the majority of bolls above node 10. Lint yield results were variable between overhead sprinkle and drip irrigation systems. Mepiquat chloride did not affect yield in irrigated cotton, however did control plant height, and improve fruit retention and cotton maturity. Non-labeled glyphosate applications reduced maturity in each irrigation system in 1 of 3 years. Cotton injury caused by conventional herbicides resulted in yield loss and poor returns compared to glyphosate systems. Early-season weed competition from low input herbicide programs caused cotton biomass reduction. High costs of conventional herbicide programs offset the available profit margin compared to glyphosate systems when yields were similar. Glyphosate systems provided excellent control of all weed species, while conventional herbicides gave acceptable control in most cases. Glyphosate resistant cotton cultivars with had better yield and returned more profit than the same cultivars treated with conventional herbicides.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-09092004-101557 |
| Date | 09 September 2004 |
| Creators | Nuti, Russell C |
| Contributors | Randy Wells, David Jordan, Alan York, Art Wollum, Keith Edmisten |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-09092004-101557/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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