Efficacy of Metamifop for the Control of Common Bermudagrass

Abstract

<jats:p>Metamifop is a postemergence aryloxyphenoxypropionic acid herbicide used for the control of annual and perennial grass weeds in cereal crops and rice (<jats:italic>Oryza sativa</jats:italic> L.). Previous research observed creeping bentgrass (<jats:italic>Agrostis stolonifera</jats:italic> L.) tolerance to applications of metamifop, suggesting utilization for the removal of encroaching bermudagrass (<jats:italic>Cynodon</jats:italic> Rich.) from creeping bentgrass putting greens with little to no phytotoxicity. Therefore, the objective of our research was to evaluate the efficacy of metamifop for common bermudagrass [<jats:italic>Cynodon dactylon</jats:italic> (L.) Pers.] control in a greenhouse environment. Experiments were conducted at the Plant and Soil Science greenhouse facility at Texas Tech University in Lubbock in 2011 and 2012. ‘Riviera’ and ‘Savannah’ common bermudagrass were seeded at 218 lb/acre into 4-inch square pots containing a soilless potting media on 26 Aug. 2011 and 14 Nov. 2011. Pots were allowed to mature in the greenhouse over a 3-month period where they were maintained at a height of 0.25 inches. Herbicide treatments were applied on 1 Dec. 2011 and 8 Feb. 2012 and consisted of metamifop at 0.18, 0.27, 0.36, or 0.45 lb/acre. A sequential application of each treatment was made on 22 Dec. 2011 and 29 Feb. 2012. A nontreated control was included for comparison. Clipping ceased after initial herbicide treatment and pots produced biomass for 3 weeks. Biomass above 0.25 inch was removed from each pot, dried, and weighed. This procedure was conducted again 3 weeks after sequential treatments. The rate of metamifop required to reduce bermudagrass growth 50% (GR<jats:sub>50</jats:sub>) was calculated 3 and 6 weeks after initial treatment (WAIT). Visual ratings of percent bermudagrass control were recorded weekly on a scale of 0% (no control) to 100% (completely dead bermudagrass). As metamifop rate increased, bermudagrass biomass decreased. The calculated GR<jats:sub>50</jats:sub> at 3 WAIT for ‘Savannah’ and ‘Riviera’ was 0.19 and 0.14 lb/acre, respectively. Nontreated control pots exhibited 0% control and produced 0.59 to 0.83 g of biomass at 3 WAIT, regardless of cultivar. Metamifop at 0.27 to 0.45 lb/acre exhibited 96% to 100% bermudagrass control at 3 WAIT, regardless of cultivar. Bermudagrass subjected to those same treatments only produced 0.01 to 0.03 g of biomass at 3 WAIT, regardless of cultivar. The 0.18-lb/acre rate of metamifop exhibited only 9% control of ‘Savannah’ bermudagrass with 0.72 g of biomass collected, while ‘Riviera’ was controlled 41% with 0.38 g of biomass collected. The calculated GR<jats:sub>50</jats:sub> at 6 WAIT for ‘Savannah’ and ‘Riviera’ was 0.13 and 0.14 lb/acre, respectively. Sequential applications of metamifop at 0.27 to 0.45 lb/acre completely controlled bermudagrass (100%) at 6 WAIT, while a sequential application at 0.18 lb/acre only controlled bermudagrass 8% to 19% at 6 WAIT, regardless of cultivar. Bermudagrass subjected to 0.18 lb/acre exhibited 0.48 to 0.56 g of biomass at 6 WAIT, regardless of cultivar. Metamifop shows potential as an alternative control option for common bermudagrass present within cool-season turfgrass species.</jats:p>

Tolerance of Bentgrass (Agrostis spp.) to Postemergence Applications of Metamifop

“…Metamifop may be an alternative option for the control of bermudagrass in bentgrass turf (Cox and Askew, 2011; Doroh et al, 2011; Cooper et al, 2016; McCullough et al, 2016). However, bentgrass safety may be cultivar dependent.…”

“…This procedure was conducted again 3 wk after sequential treatments. Previous research evaluated 3‐wk clipping production to describe turfgrass response to herbicides (Henry and Hart, 2004; Cooper et al, 2016). This methodology was chosen to accumulate more clipping biomass for ease of determining cultivar response differences to metamifop rate.…”

“…McCullough et al (2016) reported an herbicide dose causing 50% response (GR 50 ) for bermudagrass treated with metamifop of 60 g a.i. ha −1 , whereas Cooper et al (2016) reported GR 50 values for ‘Savannah’ and ‘Riviera’ common bermudagrass [ Cynodon dactylon (L.) Pers.] of 147 and 158 g a.i.…”

Common carpetgrass (Axonopus fissifolius) control with POST herbicides

“…Less control (60% to 87%) was observed in the field 4 WAT in response to those same applications. Sequential applications of metamifop (0.3 to 0.5 kg ai ha −1 ) applied in the greenhouse completely controlled bermudagrass (100%) 6 WAIT (Cooper et al 2016), whereas sequential applications of metamifop (0.4 kg ai ha −1 ) in the field only controlled bermudagrass 36% 9 WAIT (Doroh et al 2011).…”

Metamifop as an estrogen-like chemical affects the pituitary-hypothalamic-gonadal (HPG) axis of female rice field eels (Monopterus albus)

“…Metamifop (MET) ((R)-2-[4-(6-chloro-1,3-benzoxazol-2-yloxy) phenoxy]-2′-fluoro-N-methyl propionanilide), an AOPP herbicide developed by Dongbu Hannong Chemical Co., Ltd (South Korea), can effectively control annual weeds by inhibiting the activity of acetyl-CoA carboxylase (ACCase), thereby interfering with lipid synthesis ( Xia et al, 2016 ). Due to its high safety to cereal crops, MET has been widely used around the world, including China, Korea, Japan, Philippines ( Parker et al, 2015 ; Cooper et al, 2016 ). The half-life of MET varies in different environments, for example, 15.83–17.5 days in laboratory water (pH = 7.0) ( Saha et al, 2018 ), 21.5–40.80 days in paddy fields ( Wang et al, 2012 ), and about 70 days in soil ( Janaki and Chinnusamy, 2012 ).…”