Investigation of Occurrence and Hazards of Main Weeds in Autumn in Jintan Tea Garden in Jiangsu Province

A survey of main weed species in autumn was conducted using an M-Pattern with 9 sampling points in Jintan tea garden. The results showed that there were 83 weed species. Among them,gramineae weed 10 species,occupied 12. 05 %; Broadleaf weed 67species,occupied 80. 72 %; Cyperaceae weed 3 species,other weed 3 species,each occupied 3. 61 %. 10 types of vines weed were found,which accounted for 14. 93 % of Broadleaf weed. Through data analysis,we found that the dominant weeds in autumn were Digitaria sanguinalis,Echinochloa var. his-pidula,Eleusine indica,Erigeron annuus,Acalypha australis,Oxalis corniculata,Cyperus iria,Rostellularia procumbens,Cocculus orbiculatus,Euphorbia hirta,Paederia scandens var. tomentosa,Conyza canadensis,Portulaca oleracea,which relative abundance were greater than 5 %. In this paper,we analyzed and compared the type and quantity of weed populations of dominant weeds in autumn between newly planted tea field and old tea garden,and we also elaborated the community composition and the changes in the type and quantity of weed populations of dominant weeds in autumn in Jintan tea garden since the 1950s.