Occurrence investigation of weeds and activity evaluation of pre-emergence treatment herbicides on Digitaria sanguinalis in Jianghuai dry direct-seeding rice fields
In order to clarify the occurrence of weeds in dry direct-seeding rice fields in Jianghuai region and the precventive and control technology of Digitaria sanguinalis.From 2023 to 2024,the inverted W nine-point sampling method was used to investigate weeds in 320 fields in 32 townships of 6 cities in Jianghuai region.At the same time,the whole plant bioassay method was used to determine the activity of 8 pre-emergence herbicides against resistant(resistance to metamifop,the same below)and sensitive D.sanguinalis populations.A total of 57 species of weeds were investigated in the dry direct-seeding rice fields in Jianghuai region,belonging to 25 families,of which Gramineae and Asteraceae were the majority,accounting for 15.79％and 12.28％respectively.The weed community in the survey area was mainly composed of D.sanguinalis and Echiniochloa crus-galli.The dominant weeds were D.sanguinalis,E.crus-galli,Eclipta prostrata,and Acalypha australis.The diversity and complexity of weed communities in dry direct-seeding rice fields in Huaian,Chuzhou and Nantong were high.The weed communities in Yangzhou and Taizhou,Yancheng and Chuzhou were similar.Eight kinds of pre-emergence herbicides had good herbicidal activities against resistant and sensitive populations of D.sanguinalis,and the best control effect of butralin and pendimethalin on D.sanguinalis.The GR90 values of resistant and sensitive populations of D.sanguinalis were 200.61,190.35,98.96,91.31 g(a.i.)/hm2 respectively.D.sanguinalis,E.crus-galli,E.prostrata,A.australis were the dominant weeds in Jianghuai dry direct-seeding rice fields.The weed community mainly composed of D.sanguinalis and E.crus-galli in dry direct-seeding rice fields.The weed communities in dry direct-seeding rice fields in Yangzhou and Taizhou,Yancheng and Chuzhou were similar.The eight herbicides had good herbicidal activities against resistant and sensitive populations of D.sanguinalis.
万方数据
维普
