Multiple herbicide resistance in barnyardgrass (Echinochloa crus-galli) in direct-seeded rice in the Philippines

作者：Juliano Leylani M; Casimero Madonna C; Llewellyn Rick^*

来源：International Journal of Pest Management, 2010, 56(4): 299-307.

DOI：10.1080/09670874.2010.495795

• barnyardgrass
• Echinochloa crus-galli (ECHCG)
• multiple resistance
• herbicide screening
• dose-response assays
• LD50 values

Barnyardgrass (Echinochloa crus-galli [L.] Beauv.), a troublesome weed in rice production, has been confirmed for the first time to be resistant to both chloroacetamide (butachlor)- and acetanilide (propanil)-group herbicides commonly used in direct-seeded rice in the Philippines. Resistance screening showed that 17 of 18 sampled populations (94%) were resistant to butachlor+propanil. Dose-response assays using butachlor+propanil on the populations resulted in all but one not being controlled at twice the recommended rate for field application (1.4kg ai or 2l/ha) and seven populations not being controlled by 4l/ha (2.8kg ai). Dose-response assays using butachlor and propanil separately indicated that the latter populations were resistant to both of the herbicides. LD50 values for butachlor+propanil populations ranged from 0.6l/ha (0.42kg ai) to 2.9l/ha (2.03kg ai) indicating 1.9 to 9.1 times less sensitivity than a known susceptible population. Thus, what was perceived by farmers to be reduced herbicide efficacy is actually herbicide resistance. Hence, this new development in major herbicides has become a threat in rice production and will alter weed management in direct-seeded rice. Concerted efforts in raising awareness on herbicide resistance and implementing an effective integrated weed management program are needed.

• 单位
  中国水稻研究所; CSIRO