A survey questionnaire was sent to cotton consultants of Arkansas and Mississippi through direct mail and Louisiana and Tennessee consultants through on-farm visits in fall of 2011. The survey was returned by a total of 22 Arkansas, 17 Louisiana, 10 Mississippi, and 11 Tennessee cotton consultants, representing 26, 53, 13, and 38% of total cotton planted in these states in 2011, respectively. Collectively, the area planted to glyphosate-resistant (Roundup Ready®, RR) cotton was 97%, glyphosate plus glufosinate-resistant (Widestrike® Flex, WRF) cotton was 30%, and glufosinate-resistant (Liberty Link, LL) cotton was 2.6% of the total cotton surveyed in 2011. Seventy percent of area in all states is still under continuous RR/WRF cotton. Average cost of herbicides in RR systems was $114 ha−1 and in LL systems was $137 ha−1. Across the states, cotton planted under no-tillage, conservation tillage, and conventional tillage was 31, 36, and 33%, respectively, of total scouted cotton. Area under conventional tillage increased and conservation tillage decreased in Arkansas compared with a previous survey conducted in 2006. Palmer amaranth, morningglories, and horseweed in the order of listing were the most problematic weeds of cotton across Arkansas, Mississippi, and Tennessee. In Louisiana, however, morningglories were the most problematic weed followed by Palmer amaranth and common waterhemp. Glyphosate-resistant (GR) Palmer amaranth infested only 13% of scouted cotton area in Louisiana compared with 75% in the remaining three states, and consequently, hand-weeding to control GR Palmer amaranth is practiced on only 2.5% of total scouted area of Louisiana and 49% of the scouted area of the remaining three states. Hand-weeding added an additional $12 to 371 ha−1 to weed-management costs. One-half (50%) of the cotton consultants emphasized the need for more research on residual herbicides that can control GR Palmer amaranth effectively.
Nomenclature: Glufosinate; glyphosate; common waterhemp; Amaranthus rudis Sauer; horseweed; Conyza canadensis L. Cronq.; morningglories; Ipomoea spp.; Palmer amaranth; Amaranthus palmeri (S.) Wats.; cotton; Gossypium hirsutum L.
Se envió una encuesta a consultores en producción de algodón de Arkansas y Mississippi mediante correo directo y de Louisiana y Tennessee mediante visitas en finca en el otoño 2011. La encuesta fue completada y devuelta por 22 consultores de Arkansas, 17 de Louisiana, 10 de Mississippi, y 11 de Tennessee, lo que representó 26, 56, 13, y 38% del total del área sembrada con algodón en estos estados en 2011, respectivamente. Colectivamente, el área sembrada con algodón resistente a glyphosate (Roundup Ready®, RR) fue 97%, resistente a glyphosate más glufosinate (Widestrike® Flex, WRF) fue 30%, y resistente a glufosinate (Liberty Link, LL) fue 2.6% del total de la muestra en 2011. El 70% del área en todos los estados está todavía bajo algodón RR/WRF continuo. El costo promedio de los herbicidas en sistemas RR fue $114 ha−1 y en sistemas LL fue $137 ha−1. Entre todos los estados, el algodón sembrado bajo labranza cero, labranza de conservación, y labranza convencional fue 31, 36, y 33%, respectivamente, del total del algodón muestreado. El área con labranza convencional incrementó y con labranza de conservación disminuyó en Arkansas al compararse con la encuesta anterior realizada en 2006. Las malezas Amaranthus palmeri, Ipomoea spp., y Conyza canadensis fueron las más problemáticas en or
