A Review on Reasons of Increasing Perennial Weeds and Control Technology of Perennial Weeds in Heilongjiang Province

The main reasons that perennial weeds has becoming the dominant weeds in Heilongjiang Province were summarized.The biological mechanism that explained why it was difficult to control perennial weeds was analyzed. During dormancy course,variation regularity of some inner matters in perennial weeds was researched and new tentative for controlling the perennial weeds was pointed out.