Weed chemical control in oilseed rape (Braasiea napus L.)

Several herbicides, applied alone or in sequence, were tested for weed control in oilseed rape in Saïss and Gharb régions. Used as preplanting herbicides, metazachlore (1250 g a.i/ha) and butam (3600 g a.iJha) gave the best control ofweeds. Applied in post-emergence, clopyralid (100 g a.i./ha) alone or mixed with dimefuron (1000 g a.i/ha) showed the best results. Good control ofweeds was also obtained by sequences in which preplanting herbicides were followed either by clopyralid or by (clopyralid + dimefuron). The obtained herbicides efficacies may be classified as good to excellent in Saïss and moderate in Gharb. Tested herbicides improved oilseed rape yields by 45 to 127% comparatively to unweeded plots. However, weeds reduced the yield by 56.2% in weedy plots.

Key words : Oilseed rape - Herbicides - Efficacy - Yield - Gharb - Saïss