Species and Distribution of Weeds in Tobacco Fields in Xiangyang

In order to clarify the weed species,their distribution and the main noxious species in major tobacco-producing areas in Xiangyang of Hubei province,and to provide technical support for high quality tobacco production,the survey were carried out in 6 towns in Baokang,Nanzhang and Xiangzhou where the tobacco-planting area was large in September,2011.The results showed that there were 50 weed species belonging to 23 families in tobacco fields in Xiangyang.The dominant species were Digitaria sanguinalis,Acalypha australis,Polygonum nepalense,Galinsoga parvifl and Stellaria media.Weeds with high frequency ranked as A.australis,P.nepalense,G.parvifl,D.sanguinalis and S.media.According to weed density and frequency,the most noxious weed species in tobacco fields in Xiangyang ranked as D.sanguinalis,A.australis,P.nepalense,G.parvifl and S.media,which should be focused on in weed control.The altitude had certain influence on weed species and their distribution.There were more weed species at lower altitude.