Persistent Link:
http://hdl.handle.net/10150/198136
Title:
Round Ready Flex Cotton: Glyphosate Tolerance and Weed Management 2002-2003
Author:
McCloskey, William B.; Adu-Tutu, Kwame O.; Hicks, T. Vint
Affiliation:
Department of Plant Sciences, University of Arizona, Tucson, AZ; Monsanto Company, Fountain Hills, AZ
Issue Date:
May-2004
Publisher:
College of Agriculture, University of Arizona (Tucson, AZ)
Journal:
Cotton: A College of Agriculture and Life Sciences Report
Abstract:
The tolerance of Roundup Ready (RR) Flex cotton to topical Roundup Weathermax (glyphosate) applications and weed management programs in RR Flex cotton were studied in 2002 and 2003 at the University of Arizona Maricopa Agricultural Center. RR Flex cotton demonstrated excellent tolerance to glyphosate as measured by flower pollen shed and lint yield when sprayed topically with glyphosate at 2.25 lb ae/A four times (at the 3 leaf, 6 node, 10 node and 14 node growth stages). Line 1445 containing the current commercial RR genetic construct had a flower sterility/pollen shed rating of 4.6 (1 equals full pollen shed and 5 equals no pollen shed) on 28 June 2003 compared to ratings of 1.1 to 1.9 in lines containing the RR Flex genetic construct. Cotton yields followed a similar pattern with 1145 yielding 386 lb seed cotton/A compared to 1477 to 1894 lb seed cotton/A for the best lines containing the RR Flex genetic construct (yields were generally low because all lines had a Cocker genetic background that is not adapted to hot desert production conditions.) The presence of the RR gene did not affect the yield of genotype pairs that were identical except for the presence or absence of the RR Flex genetic construct. In the weed management study, delaying the first topical glyphosate application resulted in larger, more difficult to control weeds and reduced cotton yield by allowing greater early season competition between weeds and cotton. The best weed control programs included early (1 to 2 leaf growth stage) topical applications at rates greater than 0.75 lb ae/A and a second Roundup application after the first post-planting irrigation (10 node growth stage). The data also suggested that there may be significant value in making a layby, directed-broadcast application that includes a residual herbicide such as prometryn at layby.
Keywords:
Agriculture -- Arizona; Cotton -- Arizona; Weed control
Series/Report no.:
AZ1335; Series P-138

Full metadata record

DC FieldValue Language
dc.titleRound Ready Flex Cotton: Glyphosate Tolerance and Weed Management 2002-2003en_US
dc.contributor.authorMcCloskey, William B.en_US
dc.contributor.authorAdu-Tutu, Kwame O.en_US
dc.contributor.authorHicks, T. Vinten_US
dc.contributor.departmentDepartment of Plant Sciences, University of Arizona, Tucson, AZen_US
dc.contributor.departmentMonsanto Company, Fountain Hills, AZen_US
dc.date.issued2004-05-
dc.publisherCollege of Agriculture, University of Arizona (Tucson, AZ)en_US
dc.identifier.journalCotton: A College of Agriculture and Life Sciences Reporten_US
dc.description.abstractThe tolerance of Roundup Ready (RR) Flex cotton to topical Roundup Weathermax (glyphosate) applications and weed management programs in RR Flex cotton were studied in 2002 and 2003 at the University of Arizona Maricopa Agricultural Center. RR Flex cotton demonstrated excellent tolerance to glyphosate as measured by flower pollen shed and lint yield when sprayed topically with glyphosate at 2.25 lb ae/A four times (at the 3 leaf, 6 node, 10 node and 14 node growth stages). Line 1445 containing the current commercial RR genetic construct had a flower sterility/pollen shed rating of 4.6 (1 equals full pollen shed and 5 equals no pollen shed) on 28 June 2003 compared to ratings of 1.1 to 1.9 in lines containing the RR Flex genetic construct. Cotton yields followed a similar pattern with 1145 yielding 386 lb seed cotton/A compared to 1477 to 1894 lb seed cotton/A for the best lines containing the RR Flex genetic construct (yields were generally low because all lines had a Cocker genetic background that is not adapted to hot desert production conditions.) The presence of the RR gene did not affect the yield of genotype pairs that were identical except for the presence or absence of the RR Flex genetic construct. In the weed management study, delaying the first topical glyphosate application resulted in larger, more difficult to control weeds and reduced cotton yield by allowing greater early season competition between weeds and cotton. The best weed control programs included early (1 to 2 leaf growth stage) topical applications at rates greater than 0.75 lb ae/A and a second Roundup application after the first post-planting irrigation (10 node growth stage). The data also suggested that there may be significant value in making a layby, directed-broadcast application that includes a residual herbicide such as prometryn at layby.en_US
dc.subjectAgriculture -- Arizonaen_US
dc.subjectCotton -- Arizonaen_US
dc.subjectWeed controlen_US
dc.identifier.urihttp://hdl.handle.net/10150/198136-
dc.relation.ispartofseriesAZ1335en_US
dc.relation.ispartofseriesSeries P-138en_US
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