%0 Journal Article %T Peanut Cultivar Response to Flumioxazin Applied Preemergence and Imazapic Applied Postemergence %A W. J. Grichar %A P. A. Dotray %A M. R. Baring %J International Journal of Agronomy %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/371847 %X Field studies were conducted during 2009 and 2010 in Texas at Yoakum and Lamesa to determine peanut cultivar response to flumioxazin applied preemergence (0.053, 0.107, and 0.214£¿kg£¿ai£¿ha£¿1) and imazapic applied postemergence (0.035, 0.071, and 0.141£¿kg£¿ai£¿ha£¿1). At Yoakum, two cultivars (Tamrun OL01, Tamrun OL07) were evaluated while at Lamesa, four cultivars (FlavorRunner 458, Tamrun OL01, Tamrun OL02, and Tamrun OL07) were evaluated. In 2009, no stunting was noted at Yoakum with any herbicide regardless of cultivar. At Lamesa, FlavorRunner 458 and Tamrun OL01 were stunted at least 6% with the 0.21£¿kg£¿ha£¿1 rate of flumioxazin and 6 to 17% with the 0.07 and 0.14£¿kg£¿ha£¿1 rate of imazapic. Tamrun OL02 was stunted by all rates of flumioxazin (5%) and imazapic (5 to 18%) while Tamrun OL07 was stunted by all rates of flumioxazin (6 to 12%) and imazapic (7 to 15%) with the exception of flumioxazin at 0.05£¿kg£¿ha£¿1. Flumioxazin did not have an effect on yield while all imazapic rates reduced yields when compared with the non-treated control. In 2010 at Yoakum, little (<2%) or no herbicide stunting was noted on any cultivar and only imazapic at 0.14£¿kg£¿ha£¿1 caused significant stunting (7%). No yield differences were noted between herbicides regardless of cultivar. At Lamesa, all cultivars were affected (6 to 9% stunting) by herbicide treatments. No peanut stunting was noted with flumioxazin at 0.05£¿kg£¿ha£¿1 while imazapic at 0.04£¿kg£¿ha£¿1 and flumioxazin at 0.11£¿kg£¿ha£¿1 resulted in 4 and 6% stunting, respectively. Flumioxazin at 0.21£¿kg£¿ha£¿1 and imazapic at 0.07£¿kg£¿ha£¿1 resulted in 12% stunting and imazapic at 0.14£¿kg£¿ha£¿1 stunted peanut 19%. Both Tamrun OL01 and Tamrun OL07 produced lower yields (¡Ü6369£¿kg£¿ha£¿1) than FlavorRunner 458 (7252£¿kg£¿ha£¿1). Tamrun OL02 yields were intermediate (6889£¿kg£¿ha£¿1). Peanut yields from herbicide treatments were not different from the non-treated control. 1. Introduction Flumioxazin is an N-phenyl phthalamide soil-applied herbicide that received a federal label in the US for use in peanut in 2001 [1]. Flumioxazin inhibits the enzyme protoporphyrinogen oxidase [2¨C4]. In Georgia, flumioxazin applied preemergence (PRE) was shown to control morningglory species (Ipomoea spp.), prickly sida (Sida spinosa L.), and Florida beggarweed (Desmodium tortuosum (Sw.) DC) [5] while in Texas, pitted morningglory (Ipomoea lacunose L.) was controlled greater than 75% [6]. Also, flumioxazin is used in the Virginia-Carolina area for early-season suppression of Palmer amaranth (Amaranthus palmeri S. Wats.) and other broadleaf weeds (D. Jordan, %U http://www.hindawi.com/journals/ija/2013/371847/