Influence of tank mixture of herbicides on weed control in upland cotton (Gossypium hirsutum)

Abstract

A field study was carried out at ,Hisar tion) @ 1.50 kgha significantly reduced the during the rainy season of 1990 and 1991. population and dry weight of total weeds at The soil was low in nitrogen, medium in 60 days after sowing compared with the phosphorus and high in potassium. H 777 weedy check (Table 1). Combination of upland cotton (Gossypium hirsutum L.) was these herbicides in a ratio of 1 : 1 did not sown on 26 May 1990 and 17 May 1991. improve the control of weeds compared All the other cultural practices were fol- with their sole treatments. The dry weight lowed in accordance with the local package of total weeds in plots where fluchloralin of practices. The experiment was laid out in was used alone or as tank mixture with randomized block design with 3 replica- oxadiazon was less than when higher dose tions. The treatments used were: oxadiazon of pendimethalin or oxadizon or their mix- @ 0.75 and 1 .OO kglha, pendimethalin @ ture. The seed-cotton yields under the treat- 1.00 and 1.50 kglha and oxadiazon + ment of pendimethalin or fluchloralin or pendimethalin @ 0.50 + 0.50 kgha and their mixture or oxadiazon @ 1.0 kglha or 0.75 + 0.75 kgha (applied pre-emergence), oxadiazon + fluchloralin @ 0.75 + 0.75 kg1 while fluchloralin @ 1.00 and 1.50 kglha, ha were significantly more than that under fluchloralin + pendimethalin @ 0.50 + 0.50 the weedy check. The maximum seed-cotton kgoa and $75 + 0.75 kglha and oxadiazon yield was registered with weed-free check + fluchloralin @ 0.50 + 0.50 and 0.75 + but remained on a par with pendimethalin 0.75 kgha (applied as pre-plant incorpora- applied. @ 1.50 kglha at pre-emergence tion) with weedy and weed-free checks. All stage (Table 1). Similar results were re- the herbicides were applied by knap-sack ported by Balyan et al. (1983) with sprayer using 650 litres waterha. Weed pendimethalin or fluchloralin and Panwar et counts (No./m2) and dry weight of total al. (1989) with oxadiazon. weeds (g/m2) were recorded at 60 days after REFERENCES sowing by using 0.50 m x 0.50 m quadrat. Balyan, R. S., Bhan, V. M. and Singh, S. P. 1983. The dominant weeds identified were: carpet Chemical and cultural weed control in cotton. weed (Trianthema portulacastrum L.) and Tropical Pest Management 29 : 56-59. nut sedge (Cyprus rotundus L.). - Panwar, R. S., Malik, R. K., Bhan, V. M. and Malik, Pendimethalin (pre-emergence) @ 1.50 R. S. 1989. Evaluation of pre-emergence kglha or oxadiazon pre-emergence @ 1.50 and postemergence herbicides in cotton. Jnurnal ($Research, Haryana Agricultural University. kglha or fluchloralin (pre-plant incorpora- Hisar 19 : 235-239.