Performance of Diclosulam in Conventional and Strip-Tillage Peanut; Physiological Behavior of Flumioxazin in Cotton, Peanut, and Selected Weeds; Peformance of Flumioxazin in Cotton; and Morningglory Reponse to Neighboring Plants and Structure.

Abstract

Research evaluated new herbicides to improve weed management in conventional and minimum-tillage production in cotton and peanut, herbicide physiology in cotton, peanut, and selected weeds, and morningglory response to neighboring plants and objects. Diclosulam preemergence plus metolachlor PRE in conventional and strip-tillage peanut production usually controlled common lambsquarters, common ragweed, eclipta, prickly sida, and entireleaf morningglory. Flumioxazin applied preplant at 71 or 105 g ai/ha tank mixed with the isopropylamine salt of glyphosate at 1.12 kg ai/ha, paraquat at 1.05 kg ai/ha, or with the trimethylsulfonium salt of glyphosate at 1.12 kg ai/ha controlled common chickweed, common lambsquarters, common ragweed, Palmer amaranth, and smooth pigweed ≥ 96% at 29 to 43 days after treatment. Differential absorption, translocation, and metabolism at various growth stages, as well as the development of a bark layer, are the bases for differential tolerances of cotton at different growth stages to flumioxazin applied as a postemergence-directed spray. Morningglories initial planting distance from structures as well as the structures spectral reflectance influenced the percentage of ivyleaf morningglory that exhibited climbing growth as well as their final weight. Flumioxazin treatments at 1.4 mmol/L did not influence germination compared to non-treated peanut across all temperature regimes. Peanut treated with flumioxazin PRE and receiving irrigation at emergence and at 2 and 4 d after emergence were injured between 40 and 60%, while peanut treated at 8 and 12 d after emergence were injured between 25 and 15%, respectively. Total 14C absorbed by ivyleaf mornigglory was 57% of applied while sicklepod absorbed 46%, at 72 hours after treatment (HAT). Peanut absorbed > 74% of applied 14C 72 HAT. Ivyleaf morningglory contained 41% of the parent herbicide 72 HAT while sicklepod and peanut contained only 24 and 11% parent compound, respectively. Regression slopes indicated slower metabolism by ivyleaf morningglory compared to sicklepod and peanut.