嘧草硫醚对棉花的安全性及除草生物活性测定

Activity and Safety of Pyrithiobac-sodium to Cotton in Greenhouse

采用温室盆栽生物测定法,对比测定了10%嘧草硫醚水剂和50%乙草胺乳油、25%氟磺胺草醚乳油对棉花的安全性及除草活性差异。试验结果表明10%嘧草硫醚水剂土壤处理对棉花安全,茎叶处理高浓度对棉花有轻微药害,ED10值为322.69ga.i./hm2。10%嘧草硫醚水剂土壤处理对单、双子叶杂草均有较好的防效,对反枝苋、马唐、稗草、苘麻的ED90值分别为39.85、272.05、309.87、459.01ga.i./hm2;与乙草胺相比,嘧草硫醚的活性略高于乙草胺,尤其对苘麻的防效明显高于乙草胺。10%嘧草硫醚水剂茎叶处理对反枝苋防效最好,ED90值小于15ga.i./hm2;其次为稗草、苘麻,ED90值分别为125.27、486.10ga.i./hm2;该药对马唐仅有抑制作用,防除作用较差,ED90值为2771.57ga.i./hm2。与25%氟磺胺草醚乳油相比,二者杀草谱相近,嘧草硫醚作用速度较慢,氟磺胺草醚作用速度较快,但氟磺胺草醚不可用于棉田。

The activity of pyrithiobac-sodium to weeds in pot was tested with precise sprayer in greenhouse. The results show that pyrithiobac-sodium is safe to cotton sprayed pre-emergence, but toxic to cotton sprayed post- emergence in high concentration. The ED10 of pyrithiobac-sodium to cotton is 322.69 g a.i./ha. Pyrithiobac- sodium has higher pre-emergence efficacy to weeds than acetochlor, and the pre-emergence ED90 to pigweed（Amaranthus retrotlexus L.）, crahgrass（Digitaria sanguinalis （L.） Scop.）, barnyardgrass（Echinochloa crusgalli （L.） Beauv.） and velvetleaf（Abutilon theophrasti Medic.） are 39.85, 272.05, 309.87 and 459.01 g a.i./ha, respectively. Pyrithiobac-sodium has highest post-emergence efficacy to pigweed, the post-emergence ED90 to pigweed is less than 15 g a.i./ha, followed by harnyardgrass and velvetleaf, as 125.27 and 486.10 g a.i./ha. Pyrithiohac-sodium has lowest activities to crabgrass, the ED90 is 2771.57 g a.i./ha. Pyrithiobac-sodium act more slowly than fomesafen, but fomesafen can not be used in cotton.