Lawrence L. Falconer

Differences in Glyphosate-Resistant Weed Management Practices over Time and Regions

The objective of this research was to describe proportional differences across time and region in management practices among southern cotton farmers who experienced glyphosate-resistant (GR) weeds on their farms earlier than those who experienced them later and among farmers who were closest to one of four historical outbreak epicenters: Lauderdale County, TN; Macon County, GA; Edgecombe County, NC; and Terry County, TX. A mail survey was conducted with cotton farmers in 2012 from 13 southern, cotton-producing states. Survey responses on practices used by farmers were classified into three broad categories of labor, mechanical/tillage/chemical (MTC), and cultural. Proportions of respondents using practices from each category were identified by time and region; across which, proportional-difference tests were conducted. Results indicated respondents encountering GR weeds earlier were more likely than farmers who experienced them later to use the three broad-category practices (labor, 98 vs. 92%; MTC, 95 vs. 89%; and cultural, 86 vs. 76%) and specific practices, including hooded sprayers (76 vs. 58%), in-season herbicide change (83 vs. 60%), and field-border management (60 vs. 35%). Also, respondents closest to Lauderdale County were more likely than farmers closest to Edgecombe County to use broad-labor practices (99 vs. 91%) and specific practices, including hand hoeing (96 vs. 84%), hand spraying (49 vs. 31%), spot spraying (76 vs. 59%), wick applicator (13 vs. 11%), and field-border management (58 vs. 39%). Education programs on weed management can be developed and tailored according to the time and regional differences to provide effective information and communication channels to farmers. Nomenclature: Cotton, Gossypium hirsutum L El objetivo de esta investigación fue describir las diferencias proporcionales entre productores sureños de algodón en el uso de prácticas culturales, considerando el momento y la región, para productores que han tenido malezas resistentes a glyphosate (GR) en sus fincas primero y productores que las han tenido después, y entre productores que estuvieron cerca de uno de cuatro epicentros históricos de aparición de resistencia: condado Lauderdale, Tennessee; condado Macon, Georgia; condado Edgecombe, North Carolina; y condado Terry, Texas. Se realizó una encuesta por correo con productores de algodón en 2012 en 13 estados sureños productores de algodón. Las respuestas de la encuesta sobre las prácticas usadas por los productores fueron clasificadas en tres amplias categorías: mano de obra, mecánicas/labranza/químicas (MTC), y culturales. Las proporciones de los que respondieron que usaron prácticas de cada categoría fueron identificadas por momento y región; entre las cuales se realizaron pruebas de diferencias entre proporciones. Los resultados indicaron que quienes respondieron y encontraron malezas GR temprano, tuvieron más probabilidad de usar las tres categorías de prácticas que aquellos que encontraron malezas GR después (labranza, 98 vs. 92%, MTC, 95 vs. 89%, y cultural, 86 vs. 76%) y prácticas específicas que incluyeron aspersores con coberturas de campana (76 s. 58%), cambio de herbicidas durante la temporada de producción (83 vs. 60%), y el manejo de malezas en los bordes de los campos (60 vs. 35%). Además, los encuestados más cercanos al condado Lauderdale fueron los que tuvieron una mayor probabilidad de usar prácticas con mano de obra (99 vs. 91%) que los productores cercanos al condado Edgecombe, y prácticas que incluyeron labranza manual con azadón (96 vs. 84%), aplicación de herbicidas manual (49 vs. 31%), aplicaciones dirigidas (76 vs. 59%), aplicador con azadón químico (13 vs. 11%), y manejo de malezas en los bordes del terreno (58 vs. 39%). Los programas de educación en el manejo de malezas pueden ser desarrollados y dirigidos dependiendo de las diferencias en los momentos y las regiones en que se detecta la resistencia para brindar información y canales de comunicación efectivos para los productores.

Feedstock Crop Production Costs and Biofuel Feedstock Input Costs Associated with the Production of Energy Cane and Sweet Sorghum in the Southeastern USA

Concentration of biofuel feedstock crop production in specific regions of the USA is dependent on the relative comparative advantage of production in a specific region based on several agronomic and economic factors. For the southeastern region of the USA, energy cane and sweet sorghum have been identified as two feedstock crops with the greatest potential for further development of production. This study utilized field trial data from yield studies in Louisiana to develop estimates of feedstock crop production costs and biofuel feedstock input costs for these two crops. Results indicated that feedstock production costs on a harvest yield basis, as well as the related dry matter basis, were heavily dependent on yield level. Economic research from this study indicated that energy cane had a slight cost advantage compared with sweet sorghum, although production of sorghum in certain periods during the growing season was very cost competitive with energy cane.