Absorption and activity of foramsulfuron in giant foxtail (Setaria faberi) and woolly cupgrass (Eriochloa villosa) with various adjuvants

Abstract

Greenhouse and laboratory studies were conducted to examine the activity and foliar absorption of foramsulfuron in giant foxtail and woolly cupgrass with various adjuvants. Adjuvant selection was important for giant foxtail control. Foramsulfuron provided 90% or greater giant foxtail control with the addition of methylated seed oil (MSO) or MSO plus 28% urea ammonium nitrate (UAN). When a crop oil concentrate (COC) or a nonionic surfactant (NIS) was added to foramsulfuron, giant foxtail control was only 20%. However, when 28% UAN was added to COC or NIS, control was increased to 90 and 85%, respectively. Foramsulfuron absorption and control were closely related in giant foxtail. Foliar absorption of14C-foramsulfuron in giant foxtail ranged between 35 and 90% 24 h after treatment (HAT) depending on adjuvant selection. The rate of absorption was greatest when MSO plus 28% UAN was added to foramsulfuron and absorption was maximized 4 HAT. Foramsulfuron absorption in woolly cupgrass reached its maximum levels 2 HAT with all adjuvant combinations. Although the rate of foramsulfuron absorption was quicker in woolly cupgrass, absorption trends by adjuvants were similar to those in giant foxtail. Maximum absorption of14C-foramsulfuron in woolly cupgrass was 84% with the addition of MSO plus 28% UAN. However, even with high levels of absorption, woolly cupgrass control with foramsulfuron was poor and may be related to rapid metabolism to nonphytotoxic compounds.

Increased Foliar Activity of Isoproturon+Tribenuron and Pyroxsulam Against Little Seed Canary Grass and Field Bindweed by Proper Adjuvant Selection in Wheat

“…This could be attributed to a susceptibility to the herbicidal activity in the inhibition of the acetolactatesynthase (ALS) enzyme activity (which is necessary for branched-chain amino acids) and damage in PSII due to disrusption of electron transport chain between PSII and PSI (Dayan and Watson, 2011). Moreover, the addition of adjuvants to herbicides decreased the surface tension of the herbicide solution producing smaller droplets with a low level of energy, increased the activity by enhancing spreading, wetting, absorption, retention and penetration of herbicides through plant cuticles and ultimately increased weed mortality and reduced weed density (Bunting et al, 2004;Kaczmarek et al, 2009;Mohassel et al, 2010). The same conclusion was mentioned by Baghestani et al (2008).…”

The Biology of Canadian Weeds. 141. Setaria faberi Herrm.

“…ha (1 ), or foramsulfuron (37 g a.i. ha (1 )'a methylated seed oil (MSO) provided higher control of S. faberi in comparison with when a crop oil concentrate (COC) was added instead of the MSO (Bunting et al 2004a(Bunting et al , b, 2005. When glufosinate (291 and 409 g a.i.…”

Integrated Role of Row Spacing and Adjuvant to Reduce Herbicide Dose in Maize Under Semi-Arid Conditions

“…Javaid et al (2012) reported that alkyl ether sulphate increased the efficacy of post-emergence herbicides and reduced herbicide rates without compensating weed control. However, effective weed control at reduced herbicide rates depends upon the type of herbicides being applied, type of adjuvant and characteristic of target weed species (Bunting et al, 2004). Narrow row spacing of maize negatively influenced weed growth and weed-crop competition by changing the critical period of weed interference with maize, reduced weed growth and more weed-crop competition enhanced the herbicide efficacy (Padilha et al, 2016;Khan et al, 2016).…”