Abstract:
【Objective】 To clarify the control effects of five soil treatment herbicides against annual weeds in cotton fields and their safety to cotton.
【Methods】 The field randomized block experiment were adopted. 330 g/L pendimethalin EC, 480 g/L trifluralin EC, 40% prometryn WP, 50% flumioxazin WP and 42% fluridone SC with a total of 10 treatments at different dosages were selected for the field efficacy experiment. The control effects of each treatment against annual broad-leaved weeds such as
Solanum nigrum,
Chenopodium glaucum,
Amaranthus retroflexus,
Portulaca oleracea and
Abutilon theophrasti, as well as annual gramineous weeds such as
Setaria viridis and
Echinochloa crusgalli in cotton fields were studied to evaluate the effects of the tested herbicides on the safety of cotton emergence and yield.
【Results】 The control effects of 330 g/L pendimethalin EC, 480 g/L trifluralin EC, 40% prometryn WP, 50% flumioxazin WP and 42% fluridone SC against annual broad-leaved weeds in cotton fields were 67.91%, 59.47%, 77.20%, 78.46% and 81.13% respectively, and the control effects against annual gramineous weeds in cotton fields were 81.51%, 63.08%, 65.59%, 78.64% and 81.39% respectively. The cotton emergence rates of each treatment were between 83.13% and 88.54%, showing no significant difference from that of the CK, and the cotton yields increased by 7.39% to 26.54% compared with CK. The treatment of 330 g/L pendimethalin EC 990 g a.i./hm
2 had a better control effect on annual gramineous weeds such as
Setaria viridis and
Echinochloa crusgalli than other treatments. The treatments of 50% flumioxazin 60 g a.i./hm
2 and 42% fluridone SC 288 g a.i./hm
2 had better control effects on annual broad-leaved weeds such as
Solanum nigrum,
Chenopodium glaucum,
Amaranthus retroflexus,
Portulaca oleracea and
Abutilon theophrasti in cotton fields.
【Conclusion】 The treatments of 330 g/L pendimethalin EC 990 g a.i./hm
2, 50% flumioxazin WP 60 g a.i./hm
2 and 42% fluridone SC 288 g a.i./hm
2 show preferable control effects on annual weeds in cotton fields, all of which have no negative impact on cotton emergence, and possess high safety.