Integrated weed management in garlic (Allium sativum).
Field studies were carried out during 1993-95 in a sandy-loam soil at Kanpur, Uttar Pradesh, India, to compare the efficacy of pendimethalin (0.75 kg/ha), isoproturon (0.50 kg/ha), metolachlor (1.25 kg/ha) and oxyfluorfen (0.07 kg/ha) combined with or without manual weed control, to unweeded and hand-weeded plots (after 20 days, after 20 and 40 days, and after 20, 40 and 60 days) in a local cultivar of garlic. Data were recorded on weed populations, weed biomass and clove yields. The most important weeds during 1993-95 were Phalaris minor, Chenopodium album and Anagallis arvensis, while Cyperus rotundus and Melilotus indica were important in 1993-94, and Chenopodium murale and Coronopus didymus in 1994-95. Pendimethalin and isoproturon controlled P. minor, while pendimethalin, isoproturon and oxyfluorfen controlled Chenopodium album, and pendimethalin controlled Chenopodium murale and M. indica. Herbicides + hand weeding controlled Coronopus didymus. Pendimethalin, isoproturon and oxyfluorfen + hand weeding resulted in 76-86% weed control. Manual hand weeding twice resulted in similar clove yields as herbicide applications. Herbicides + hand weeding increased clove yields significantly compared to herbicide application only. Clove yields were similar with hand weeding (3 times), and pendimethalin or oxyfluorfen + hand weeding. The greatest net monetary returns were with hand weeding 3 times (36 250 Rs/ha), followed by pendimethanil + hand weeding (29 450 Rs/ha), and oxyfluorfen + hand weeding (26 694 Rs/ha).