Absorption and Translocation of Glyphosate and Sucrose in Glyphosate-resistant Cotton

Studies were conducted to evaluate absorption and translocation of 14C-glyphosate in glyphosate-resistant (GR) cotton. Both commercial GR cotton events [glyphosate-resistant event 1, marketed as Roundup Ready®, released 1997 (GRE1), and glyphosate-resistant event 2, marketed as Roundup Ready Flex®, released 2006 (GRE2)] were evaluated at the four-leaf and eight-leaf growth stages. Plants were harvested at 1, 3, 5, and 7 d after treatment (DAT). Glyphosate absorption, as a percentage of applied, increased over time with 29 and 36% absorption at 7 DAT in four-leaf GRE1 and GRE2 cotton, respectively. In eight-leaf cotton, glyphosate absorption (33% at 7 DAT) was not different between events. Glyphosate translocation patterns were not different between events or harvest timings and exhibited a source–sink relation. Observed translocation differences between cotton growth stages were probably due to reduced glyphosate export from the treated leaf of eight-leaf cotton. An additional study compared absorption and translocation of 14C-glyphosate and 14C-sucrose in 5- and 10-leaf GRE2 cotton. Averaged over trials, 14C compounds, and growth stages, cotton absorbed 28% of the applied dose at 14 DAT. On the basis of the percentage of 14C exported out of the treated leaf, glyphosate and sucrose translocation patterns were similar, indicating that glyphosate may be used as a photoassimilate model in GRE2 cotton. Nomenclature: Glyphosate; cotton, Gossypium hirsutum L.

[1]  P. Feng,et al.  Distribution of [14C]glyphosate in mature glyphosate-resistant cotton from application to a single leaf or over-the-top spray , 2005 .

[2]  J. Ryerse,et al.  Effect of glyphosate spray droplets on leaf cytology in velvetleaf (Abutilon theophrasti) , 2004 .

[3]  S. Senseman,et al.  Effect of glyphosate application timings and methods on glyphosate-resistant cotton , 2004, Weed Science.

[4]  S. Senseman,et al.  Boll Abscission Responses of Glyphosate-Resistant Cotton (Gossypium hirsutum) to Glyphosate1 , 2003, Weed Technology.

[5]  Judith F. Thomas,et al.  Reproductive abnormalities in glyphosate-resistant cotton caused by lower CP4-EPSPS levels in the male reproductive tissue , 2002, Weed Science.

[6]  S. Askew,et al.  Absorption, translocation, and metabolism of foliar-applied CGA 362622 in cotton, peanut, and selected weeds , 2002, Weed Science.

[7]  S. Duke,et al.  Tolerance and accumulation of shikimic acid in response to glyphosate applications in glyphosate-resistant and nonglyphosate-resistant cotton (Gossypium hirsutum L.). , 2002, Journal of agricultural and food chemistry.

[8]  A. Price,et al.  Absorption and translocation of glyphosate in glyphosate-resistant cotton as influenced by application method and growth stage , 2001, Weed Science.

[9]  K. N. Reddy.  Factors Affecting Toxicity, Absorption, and Translocation of Glyphosate in Redvine (Brunnichia ovata)1 , 2000 .

[10]  Dale L. Shaner,et al.  The impact of glyphosate‐tolerant crops on the use of other herbicides and on resistance management , 2000 .

[11]  Michael A. Jones,et al.  Tolerance of Transgenic Cotton to Topical Applications of Glyphosate , 1999 .

[12]  J. Ryerse,et al.  Correlation of Leaf Damage with Uptake and Translocation of Glyphosate in Velvetleaf (Abutilon theophrasti) , 1998, Weed Technology.

[13]  W. Donald,et al.  Herbicide contamination of groundwater beneath claypan soils in North-Central Missouri , 1997 .

[14]  F. Tardif,et al.  Translocation of Glyphosate, Quizalofop, and Sucrose in Quackgrass (Elytrigia repens) Biotypes , 1993, Weed Science.

[15]  D. Wyse,et al.  Atrazine and alachlor losses from subsurface tile drainage of a clay loam soil , 1993 .

[16]  D. Geiger,et al.  Distribution of Imported Glyphosate in Quackgrass (Elytrigia repens) Rhizomes in Relation to Assimilate Accumulation , 1993, Weed Science.

[17]  R. A. Young,et al.  Water quality impacts associated with pre- and postemergence applications of atrazine in maize , 1992 .

[18]  J. Masiunas,et al.  Glyphosate Activity in Potato (Solanum tuberosum) Under Different Temperature Regimes and Light Levels , 1988, Weed Science.

[19]  L. C. Haderlie,et al.  Translocation of 14C-Glyphosate and 14CO2-Labeled Photoassimilates in Canada Thistle (Cirsium arvense) , 1985, Weed Science.

[20]  A. Appleby,et al.  A Comparison between Glyphosate and Assimilate Translocation Patterns in Tall Morningglory (Ipomoea purpurea) , 1983, Weed Science.

[21]  D. Penner,et al.  Absorption, translocation and metabolism of 14C-glyphosate in several weed species. , 1980 .

[22]  G. D. Wills.  Factors Affecting Toxicity and Translocation of Glyphosate in Cotton (Gossypium hirsutum) , 1978, Weed Science.

[23]  T. Kerby,et al.  CARBON SOURCE FOR DEVELOPING BOLLS IN NORMAL AND SUPEROKRA LEAF COTTON , 1978 .

[24]  G. Webster.  Herbicides: Chemistry, Degradation and Mode of Action. , 1977 .

[25]  D. Penner,et al.  Rapid Inactivation of Glyphosate in the Soil , 1975, Weed Science.

[26]  R. Kohel,et al.  Export of 14C‐Assimilates in Cotton Leaves1 , 1975 .

[27]  D. Penner,et al.  Adsorption, Mobility, and Microbial Degradation of Glyphosate in the Soil , 1975, Weed Science.

[28]  D. Ashley.  C-Labelled Photosynthate Translocation and Utilization in Cotton Plants 1 , 1972 .