Herbicidal characteristics of a novel protoporphyrinogen oxidase inhibitor-Y11049

In order to investigate the herbicidal characteristics of a novel protoporphyrinogen oxidase (PPO) inhibitor Y11049 (compound name was ethyl 2-((6-fluoro-5-(3-methyl-2,6-dioxo-4-trifluoromethyl-3,6-dihydropyrimidin-1(2H)-yl) benzo d thiazol-2-yl) thio) propanoate), the effects of environmental temperature, light intensity, simulated rainfall and plant growth stage on its activities against sensitive broadleaf weeds were studied by indoor bioassay method, using saflufenacil as active control; meanwhile, the absorption and conductivity of Y11049 in Cucumis sativus L. and Abutilon theophrasti were tested in greenhouse. The results showed that the herbicidal activity of Y11049 against Amaranthus hybridus was positively correlated with environmental temperature ranging from 15 ℃ to 35 ℃ at application dose of 3.75, 7.5, 15 and 30 g a.i./hm². At the application dose of 60 g a.i./hm², the inhibition rate against Pharbitis nil was 95.2% under full light (8427 lx), which was significantly higher than that under medium light (4200 lx) and low light (5 lx), indicating that Y11049 belongs to light-demanding herbicide. The inhibition rate against A. theophrasti under simulated rainfall after 4 h of the spray of Y11049 showed no significance comparing with blank control, which indicated that Y11049 is tolerant to rain-washing. At the application dose of 30 g a.i./hm², the inhibition rate against 2- to 8-leaf A. theophrasti and Amaranthus retroflexus were 86.0%-98.6% and 86.5%-97.9% under foliage treatment, respectively, which showed that Y11049 has a relative long application period. Simutaneously, Y11049 displayed moderate absorption through roots, stems and leaves, but poor conduction. Y11049 should be applied by spraying evenly on weed surface on sunny days due to its contact herbicidal activity, that it exhibited great prospect against broadleaf weeds in non-arable field.