Study on Different Methods of Weed Management in Onion (Allium cepa L.)

A weed management study on onion (Allium cepa L.) was conducted at Birsa Agricultural University, Jharkhand, India during winter season of 2016-17 and 2017-18 in a randomized block design comprised of nine weed control treatments consisting plastic mulch, available weeds mulch, straw mulch, cover crops (Fenugreek), oxyfluorfen 0.5 kg/ha pre-emergent (PE), pendimethalin 1.0 kg/ha PE, mechanical weeding by Dutch hoe, hand weeding at 20, 40, 60 days after transplanting (DAT) and weedy check. Hand weeding at 20, 40 and 60 DAT was most effective in reducing weed dry matter however it was similar to plastic mulch at all the growth stages of crop during 2016-17, 2017-18 as well as in pooled except at 60 DAT in 2016-17. Hand weeding reduced weed dry matter to the extent of 75.83 and 84.83 percent during 2016-17, 100 and 89.21 percent during 2017-18, 98.64 and 88.62 percent under pooled data at 30 and 60 DAT respectively and the corresponding reduction in weed dry matter due to application of plastic mulch was 70.73 and 40.32 percent during 2016-17, 100 and 93.64 percent during 2017-18, 98.37 and 86.52 percent under pooled data at 30 and 60 DAT respectively, compared to weedy check. Application of plastic mulch recorded 300 and 38 percent higher onion yield during 2016-17, 1959 and 117 percent during 2017-18, 576 and 70 percent higher under pooled data compared to weedy check and hand weeding respectively. Plastic mulch also recorded maximum net return 364136, 380185 and 372160 /ha during 2016-17, 2017-18 and under pooled data similar to net return with application of oxyfluorfen 0.25 kg/ha PE, pendimethalin 1 kg/ha PE and hand weeding during 2016-17 while under pooled data maximum B:C ratio was with plastic mulch and was similar to oxyfluorfen 0.25 kg/ha PE, pendimethalin 1 kg/ha PE and hand weeding.