Field Resistance of Digitaria sanguinalis (L.) Scop. to Haloxyfop-P-Methyl in China’s Cotton Fields

Large crabgrass, Digitaria sanguinalis (L.) Scop., is a devastating weed species in the cotton (Gossypium spp.) fields China. It has developed resistance to haloxyfop-P-methyl, an aryloxyphenoxypropionate herbicide known for its ability inhibit lipid synthesis and induce oxidative stress weeds, due years of continuous intensive use. Here, we present results from nation-wide, long-term monitoring effort. To understand scale level haloxyfop-P-methyl resistance, total 65 D. populations eight production provinces, including Hunan, Jiangxi, Xinjiang, Henan, Hubei, Hebei, Shanxi, Anhui, were collected 2014–2017. Based on dose response observed gradient sensitivity among field populations, ranging sensitive (8), low-level (40; 2 ≤ RI 10) moderate-level (17; 10 < 20). Although no high-level (RI > 20) was found Hunan Hebei exhibited rapid spread field-evolved resistance. After challenged with (48.600 g a.i./ha at 4–5-leaf stage), resistant susceptible responded differently activity array resistance-related enzymes, acetyl-CoA carboxylase (ACCase), glutathione S-transferase (GSTs), nicotinamide-adenine dinucleotide phosphate (NADPH) carboxylesterase (CarE), suggesting potential involvement NADPH, CarE GSTs