Herbicide Combinations in Peanut (Arachis hypogaea)

Abstract

When tank mixed with certain boadleaf-selective herbicides, fluazifop {(+)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid}, sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one}, haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid}, and fluazifop-P {(R)-2-[4-[[5-trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} were less effective in controlling two annual grasses, Texas panicum (Panicum texanumBuckl. #3PANTE) and large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA]. These herbicides were applied alone or were combined with the broadleaf-selective herbicides bentazon {3-(1-methylethyl)-(1H)-2,l,3-benzothiadiazin-4(3H)-one-2,2-dioxide} and/or 2,4-DB [4-(2,4-dichlorophenoxy)butanoic acid]. The herbicide combinations controlled smooth pigweed (Amaranthus hybridusL. # AMACH) and yellow nutsedge (Cyperus esculentusL. #CYPES). Increasing the rates of the grass-selective herbicides in the mixture reduced the adverse effects of 2,4-DB or bentazon.

Interaction of 2,4-DB With Postemergence Graminicides

“…Other researchers also have reported inconsistent responses with mixtures of postemergence graminicides and various broadleafherbicides (3,15,19,21). The magnitude of antagonism we observedwhen 2,4-DB was mixed with the graminicides is similar to that observed previously with mixtures of phenoxyalkanoic acid herbicides and postemergence graminicides (5,17,22,23,24) but less than that often observedwhen other types of broadleafherbicides are mixed with the graminicides (3,19,20,22).…”

“…In previous research (17,22,23,24), some of the postemergence graminicides were more susceptible to antagonism by a given broadleaf herbicide than were other graminicides. In our experiment, there was no indication that one graminicide was consistently more susceptible to antagonism by 2,4-DB than were the other graminicides.…”

“…Although we did not investigate the effect of increasing graminicide rates, previous research suggests an increase in the graminicide rate likely would alleviate the antagonism (5,10,17,19,24). The cost of increasing the graminicide rate may be more than offset by the costs associated with a separate application.…”

“…. Antagonism may occur when benzoic acid (1,25), aliphatic acid (5), imidazolinone (21,22), sulfonylurea (22), diphenylether (11,15,22), benzothiadiazole (15,17,20), pyridazine (15), amide (5), phenylcarba~~te (8), p~en ylurea (3), and organic arsenical (3) herbicides are mixed with the postemergence graminicides. Antagonism also may occur when phenoxyalkanoic acid herbicides such as 2,4-D [(2,-4-dichlorophenoxy)acetic acid] and MCPA [(4-chloro-2-methylphenoxy)acetic acid] are mixed with postemergence graminicides (5,7,10,24,25).…”

Defining Interactions of Herbicides with Other Crop Protection Products Applied to Peanut

“…Differential response to clethodim was noted when applied with different formulations of chlorothalonil (Jordan et al, 2003a). Increasing the interval between applications of components of the mixture can overcome negative interactions, especially herbicide-herbicide interactions (Green, 1989;Grichar and Boswell, 1987;Putnam and Ries, 1967). Applying graminicides in higher spray volumes can exacerbate the negative influence of herbicides and fungicides on weed control by graminicides (Buhler and Burnside, 1984;Jordan et al, 2003a;Kells and Wanamarta, 1987).…”