Abstract:

In order to further understand the herbicide resistance of barnyard grass [Echinochloa crus-galli (L.) P. Beauv.] in Jiangsu rice field, the seeds of barnyard grass populations were collected from rice fields in Jiangsu Province from 2019 to 2022, and the resistance of barnyard grass species to metamifop, cyhalofop-butyl, penoxsulam and quinclorac was determined by stem and leaf spray method. The suspected resistant populations of 100 collected barnyard grass populations were screened by differential dose method, and then the resistance index of these suspected resistant populations to the corresponding herbicides was determined by the series concentration of different herbicides. The results showed that there were 10 populations with low resistance, 8 populations with medium resistance and 1 population with high resistance to metamifop; there were 5 populations with low and medium resistance to cyhalofop-butyl; there were 3, 9 and 1 with low, medium and high resistance to penoxsulam, respectively; there were 1, 7 and 1 with low, medium and high resistance to quinclorac, respectively. The tested barnyard grass populations in 13 prefectural level cities in Jiangsu Province, except Changzhou, all have resistant population distribution, and some populations show multiple resistances.

Key words: Echinochloa crus-galli (L.) P. Beauv., herbicide, drug resistance, metamifop, cyhalofop-butyl, penoxsulam, quinclorac