Department of Agriculture
Master of Science
Field experiments were established in 2000 and 2001 at the Agricultural Research and Education Complex in Bowling Green, Kentucky to evaluate herbicide efficacy on annual morningglory (Ipomoea spp.) species and other weeds. A randomized complete block design was utilized in each study with each treatment being replicated three times. Plots consisted of four 76 cm rows, 9.1 m in length. The two center rows of each plot were treated, with the outside rows of each plot serving as a weedy check. Crop response, weed control, and grain yield data were collected. Four different experiments were conducted. Two experiments utilized treatments of glyphosate and sulfosate alone and with tankmixes on glyphosate-tolerant soybeans. Two experiments examined various herbicide tankmixes applied to non-glyphosatetolerant soybeans. Soybean injury influenced by postemergence treatments of glyphosate and sulfosate alone and with chlorimuron-ethyl ranged from 0 to 5% four days after treatment (DAT) with the addition of chlorimuron-ethyl resulting in greater injury. Morningglory control 14 DAT ranged from 48 to 63% with sulfosate at 700 g ai/ha providing less control than glyphosate at 1120 g ai/ha. No treatment differences occurred 29 and 42 DAT. No statistical differences among treatments occurred among other weed species evaluated. Soybean injury influenced by postemergence treatments of glyphosate and sulfosate alone and with fomesafen and chloransulam-methyl 4 DAT ranged from 0 to 17% with the addition of fomesafen resulting in greater injury than the addition of chloransulam-methyl. Momingglory control 14 DAT ranged from 60 to 88% with glyphosate + imazethapyr at 840 + 71 g ai/ha providing the least control and sulfosate + fomesafen at 700 + 201 g ai/ha providing greater control. Soybean injury influenced by pre and postemergence treatments 7 DAT ranged from 0 to 30% in conventional soybeans. Applications of carfentrazone resulted in the greatest injury. Momingglory control 20 days after planting (DAP) ranged from 0 to 99% with chloransulam + sulfentrazone providing the highest control. Momingglory control 28 DAT ranged from 30 to 99% with s-metolachlor + metribuzin + acifluorfen + fenoxaprop-ethyl + fluazifop-P providing the least control. Common cocklebur control ranged from 13% to 97% 20 DAP with pendimethalin + imazethapyr providing the least control. Treatments containing aciflourfen + bentazon controlled common cocklebur > 80% 28 DAT. Soybean injury influenced by preemergence and postemergence treatments 7 DAT in conventional soybeans ranged from 0 to 33% with sulfentrazone + clomazone + chlorimuron-ethyl + carfentrazone resulting in the greatest injury. Momingglory control 7 DAT ranged from 0 to 99% with sulfentrazone + clomazone plus chlorimuron-ethyl + carfentrazone having the greatest control. Momingglory control 28 DAT ranged from 82 to 94% with no differences among treatment.
Agriculture | Agronomy and Crop Sciences
Oveson, Dawn, "Efficacy of Soybean Herbicides on Annual Morninglory" (2001). Masters Theses & Specialist Projects. Paper 691.