Weed and Peanut (Arachis Hypogaea) Response to Diclosulam Applied Post

Abstract

Diclosulam is generally applied either PPI or PRE to peanut to control certain broadleaf weeds and suppress sedges. Research was conducted to determine efficacy and peanut response to POST applications of diclosulam at 9, 13, 18, and 27 g ai/ha. Efficacy of diclosulam was affected by application rate and environment. Common ragweed control ranged from 60 to 100%, entireleaf morningglory control from 56 to 100%, marestail control from 78 to 85%, and nodding spurge from 50 to 97%. Smooth pigweed and common lambsquarters were both controlled less than 35%. Diclosulam controlled yellow nutsedge and eclipta less than 70 and 80%, respectively. In separate experiments, diclosulam and imazapic controlled dogfennel more effectively than acifluorfen, bentazon, imazethapyr, lactofen, paraquat, or 2,4-DB. Visual estimates of peanut injury were 15% or less for all rates during both years. Peanut yield ranged from 3,340 to 3,730 kg/ha in 2002 and 5,230 to 5,820 kg/ha in 2003. Foliar injury and peanut pod yield were influenced by diclosulam rate, although no clear relation was evident. Cultivar and diclosulam rate did not interact with respect to visual injury or pod yield.

Peanut (Arachis hypogaea L.) Response to Carfentrazone-ethyl and Pyraflufen-ethyl Applied Close to Harvest

“…Diclosulam, lactofen, and 2,4-DB did not negatively affect pod yield when compared with non-treated peanut. Other research (Lancaster et al, 2007) demonstrated no detrimental effect of diclosulam applied POST to peanut 7 to 35 d after planting prior to the R1 stage of growth (Boote, 1982). Diclosulam can be applied up to 30 d after planting with minimal concern for negative impact on peanut (Anonymous, 2004;Prostko, 2004).…”

“…Imazapic, lactofen, and 2,4-DB can be applied no closer to harvest than 90, 45, and 45 d, respectively (Anonymous, 2015;Anonymous, 2016;Anonymous, 2014a). Imazapic and lactofen are marginally effective on Palmer amaranth and morningglory that are large (Chahal et al, 2011;Lancaster et al, 2005Lancaster et al, 2007 or express resistance to ALS-inhibiting herbicides which is widespread in North Carolina (Poirier et al, 2014).…”

“…Diclosulam suppresses several broadleaf weeds including annual morningglory, common ragweed, and Benghal dayflower when applied POST (Prostko, 2004;Lancaster et al, 2007). Of these herbicides 2,4-DB is applied late in the season more often to suppress Palmer amaranth and morningglory, although 2,4-DB is ineffective in controlling pitted morningglory (Ipomoea lacunosa L.) (Jordan, 2016).…”

Confirmation and Management of Common Ragweed (Ambrosia artemisiifolia) Resistant to Diclosulam

“…Although common ragweed was present across the entire field, the population density varied, and it is suspected that selection pressure for ALS-resistant biotypes most likely varied across the field based on previous cropping systems or herbicide program. Previous research (Everman et al 2006;Lancaster et al 2007) reported that diclosulam applied POST at the manufacturer's suggested use rate of 26 g ha 21 controlled ALS-susceptible common ragweed completely.…”

“…ragweed, the rate required to avoid significant peanut injury is considered low for many weed species (Anonymous 2010b). Additionally, common ragweed that is not resistant to ALS-inhibiting herbicides is considered very susceptible to diclosulam (Bailey et al 1999;Lancaster et al 2007). In experiments evaluating reduced herbicide programs in peanut with rates at or below the manufacturer's suggested use rate, diclosulam, either PRE or POST, consistently controlled common ragweed when applied at rates lower than 26 g ha 21 (Grey et al 2001;Lancaster et al 2007).…”