Evaluation of Quizalofop-Resistant Rice for Arkansas Rice Production Systems

Abstract

Due to the ongoing evolution of herbicide-resistant weeds, new technologies are needed to maintain effective levels of control. A new rice variety that will be resistant to quizalofop, an acetyl coenzyme A carboxylase-(ACCase-) inhibiting herbicide, is currently under development. With the anticipated launch of this technology in 2018, multiple experiments were conducted to determine effectiveness of the quizalofop-resistant rice system for common grass weed species found in Arkansas rice production. One hundred and twenty-six barnyardgrass populations were collected across Arkansas and treated with quizalofop at 80 g ai hato determine a baseline of response. All populations evaluated were effectively controlled (≥92%) by quizalofop, with only 13 populations resulting in lower than 98% control. A greenhouse and field trial were conducted to compare efficacy of quizalofop to currently labeled rice graminicides for control of common rice grass weeds. Results from the greenhouse experiment showed that quizalofop treatments resulted in greater efficacy of common grass weeds compared to cyhalofop or fenoxaprop. This was especially apparent at the larger grass growth stages. A field experiment conducted compared season-long weed control programs of quizalofop to fenoxaprop and cyhalofop. The quizalofop-containing treatments were no better than fenoxaprop and cyhalofop for barnyardgrass and broadleaf signalgrass control. Barnyardgrass and broadleaf signalgrass control were greater than 96% for all herbicide treatments. An additional field experiment was conducted to determine the best rate structure for sequential applications of quizalofop in rice. Sequential applications of quizalofop at 120 g ha −1 followed by 120 g ha −1 two weeks later resulted in the highest barnyardgrass and broadleaf signalgrass control. Likewise, applying the full seasonal use rate of 240 g ha −1 of quizalofop resulted in greater control compared to 200 and 160 g ha −1 . Results from this research indicate a strong benefit from quizalofop use in rice.

Aryloxyphenoxypropionate in association with others herbicides in controlling weedy rice and barnyardgrass

“…As for the bentazon, the opposite effect of increasing the dose was verified, resulting in a higher dry weight compared to the 37.5 g ha -1 dose (Table 4). The high efficiency of the quizalofop-p-ethyl (80 g ha -1 ) on the barnyardgrass was validated by Lancaster et al (2018), where excellent controlling levels (> 92%) were observed for the 126 evaluated biotypes.…”

“…Amid the main infesting-weed species of the irrigated rice are the weedy rice (Oryza sativa) and the barnyardgrass (Echinochloa spp.) (Lancaster et al, 2018).…”

Evaluation of weed control in acetyl coA carboxylase-resistant rice with mixtures of quizalofop and auxinic herbicides

“…Acetyl CoA carboxylase-resistant rice allows POST applications of quizalofop to control troublesome grass weed species in rice (Epp et al 2016;Rustom et al 2018). Lancaster et al (2018) reported that quizalofop controlled barnyardgrass >96% at the two-to three-leaf growth stage and >90% at the five-to six-leaf growth stage in ACCase-resistant rice. Webster et al (2019) reported that quinclorac and triclopyr antagonized barnyardgrass control 28 d after application when mixed with quizalofop at 120 g ha −1 .…”

Toxic Mechanisms of Aryloxyphenoxypropionates in Target and Non-target Organisms

“…ArOPPs are relatively new class of selective herbicides prepared from heterocyclic oxyphenoxy propionic acid derivatives for the control of graminaceous weeds in broad-leaved crops and tolerant cereal crops [4]. They are applied mainly on cotton, soybeans and sugar beet as well as in the wheat, corn, barley, rye, legumes, sunflowers, sesame, alfalfa, peanuts, lettuce, spinach, potatoes, cucumber, peas, tomatoes, fennel, and strawberries [5][6][7][8]. ArOPPs are post-emergence (PoEm) herbicides composed of about fifteen members.…”