Current Status of Phalaris minor Resistance against Isoproturon and Alternate Herbicides in the Rice-wheat Cropping Systems in Punjab
Abstract
Survey regaring bioefficacy of herbicides used by the Punjab farmers for the control of Phalaris minor in wheat was done during the crop season of 2005–06. On the basis of the survey report from 286 farmers belonging to different districts of Punjab it may be concluded that 38.5% used sulfosulfuron and 36.0% used clodinafop. Isoproturon is still being used by 8.7% farmers which is higher than fenoxaprop-P-ethyl (3.2%). Unrecommended herbicides were used by 13.6% farmers. More than 27% farmers used unrecommended herbicides or unapproved brands of recommended herbicides, whereas >19% of the farmers used under or over doses of herbicide. The efficacy of these herbicides; was found to be below satisfactory level by > 30% of the farmers. The poor efficacy of herbicides for the control of P. minor in wheat may be due to the use of unrecommended herbicides, under-dose, unapproved brands of the recommended herbicides, faulty application technology being adopted by the farmers. Apart from these, the possibility of development of multiple resistances by P. minor to clodinafop and sulfosulfuron cannot be ignored.
