Weed Species Distribution and Damage to Tobacco Fields in Seven Areas of Heilongjing Province

To evaluate the damage caused by weeds in tobacco fields in 7 areas in Heilongjiang Province,a survey was conducted by sampling none plots according to aWpattern. The weed flora included 33 species of which 26 were broadleaf weeds,six were grasses and one was a pteridophyte,representing 15 botanical families. Dominant species were similar among the tobacco fields of the seven areas and included Echinochloa crusgalli,Setaria viridis,Digitaria sanguinalis,Chenopodium album,Amaranthus retroflexus,Abutilon theophrasti,and Acalypha australis.