Corn Tolerance as Affected by the Timing of Foramsulfuron Applications

Abstract

Two corn hybrids were evaluated to determine tolerance to foramsulfuron applications with and without the safener, isoxadifen-ethyl at five application timings. The corn hybrid N58D1 was more sensitive to foramsulfuron applications than N59Q9. Averaged across all application timings, the addition of isoxadifen-ethyl decreased corn injury of the more sensitive corn hybrid, N58D1. Foramsulfuron application timing had a significant effect on corn tolerance. The greatest corn injury generally occurred from foramsulfuron applications to V6 and V8 corn (visible collars). Foramsulfuron injury ranged between 9 and 37% from these two application timings, 7 d after treatment (DAT). By 21 DAT, corn generally recovered from foramsulfuron injury, and there were a few cases of reduced corn yield at the end of the season. Yield reductions and ear malformations were greatest at the Urbana location with both hybrids when foramsulfuron was applied to V12 corn. The addition of isoxadifen-ethyl alleviated ear malformations and increased corn yield from this application timing. Applications of foramsulfuron before V6 corn also were important in reducing corn injury and protecting yield. Therefore, when growers are using foramsulfuron for weed control, it will be important to select proper hybrids that are more tolerant as well as making applications before V6 corn.

Tolerance of Maize (<i>Zea mays</i> L.) and Soybean [<i>Glycine max</i> (L.) Merr.] to Late Applications of Postemergence Herbicides

“…Conversely, up to 16% injury 3 DAT has been found in maize treated with twice the labeled dose of foramsulfuron and 23% injury 7 DAT for maize treated with twice the dose of dicamba/diflufenzopyr [10]. Maize tolerance to foramsulfuron can vary considerably by application timing and maize hybrid [20] [21]. In the current study, the visible injury was transient with reduced injury observed at 21, 28, and 56 DAT.…”

Evaluating Postemergence Herbicides for Relative Corn Safety

“…Growers are concerned about the impact of herbicide injury on corn and often inquire about relative crop safety. However, most trials examining crop safety usually include only one active ingredient or a limited range of herbicides (1,2,4). There is a lack of trials examining multiple herbicide modes of action for crop safety and the impact on yield to make comparisons among various active ingredients.…”

Genetic Factors Influencing Adverse Effects of Mesotrione and Nicosulfuron on Sweet Corn Yield

“…In fi eld corn, postemergence applications of foramsulfuron resulted in yield losses of 6 and 15% in two trials (Bunting et al, 2004). Applications made at later growth stages (i.e., V8-V12) resulted in greater levels of injury and yield reduction than those made at earlier growth stages (i.e., V2-V6) (Bunting et al, 2004).…”