Ecotypic Variation in Echinochloa colona - II. Intraspecific Variations in Sensitivity to Herbicides

Echinochloa colona의 생태형(生態型) 변이(變異) - II. 제초제(除草劑)에 대한 종내(種內) 반응성(反應性) 변이(變異)

  • Chun, J.C. (Department of Agricultural Chemistry, Jeonbug National University) ;
  • Moody, K. (Department of Agronomy, International Rice Research Institute)
  • Published : 1990.12.30


The intraspecific susceptibility of twelve Echinochloa colona(L.) Link ecotypes to herbicides was studied at three different stages of growth. At germination and post-germination stage, the Batangas ecotype was most susceptible to both butachlor (N-butoxymethyl-2-chloro-2', 6'-diethylacetanilide) and thiobencarb (S-4-dichlorobenzyldiethylthiocarbamate), whereas the Bukidnon ecotype was the most tolerant. The susceptibility of the ecotypes used was not associated with the seed weight and maturity. When the preemergence herbicides were applied at the 2-leaf stage of the ecotypes, the Nueva Ecija ecotype was least susceptible to butachlor at 1 ppm, but it was most susceptible to thiobencarb. The reverse was exhibited by the Cagayan ecotype. Differential susceptibility of the ecotypes to propanil (3', 4'-dichloropropionanilide) as determined by the necrotic length of the third leaf of 20-day-old seedlings was pronounced in the Camarines Sur, Iloilo, and IRRI (red) ecotypes. However, no necrotic tip appeared in the Cagayan and Batangas ecotypes. The differential responses varied with the type and the concentration of the herbicide studied and the growth stage of the ecotypes.