COMPARISON OF DIFFERENT WEED MANAGEMENT PRACTICES IN ONION (Allium cepa L.) UNDER AGROCLIMATIC CONDITIONS OF DERA ISMAIL KHAN, PAKISTAN

Field study was conducted at Agricultural Research Institute,Ratta Kulachi, Dera Ismail Khan, Pakistan during 2007 to comparedifferent weed management practices in onion cv. ‘Shah Alam’.Randomized complete block design, having three replications was used.The treatments were; 1) Dual Gold (pre-emergence) @ 2.5 L ha-1, 2)Buctril Super (post-emergence) @ 1.25 L ha-1, 3) Stomp 33% (preemergence)@ 2.5 L ha-1, 4) weeds free (manual weeding throughout theseason), 5) manual weeding (30 and 60 days after transplanting) and 6)control (no weeding). Major weeds infesting the experimental field wereAnagallis arvensis, Convolvulus arvensis, Lathyrus aphaca, Medicagodenticulata, and Melilotus indica. Statistical analysis of the data showedthat various weed control practices had significant effect on weed densityand onion yield. For controlling weeds, Stomp 33% was found to be thebest. Maximum bulb yield of 9.32 t ha-1 was found in weeds free (manualweeding throughout season) and Stomp 33% with bulb yield of 8.89 tha-1, whereas, minimum bulb yield (5.70 t ha-1) was recorded in weedycheck plots. Therefore, hand weeding throughout season or the use ofStomp 33% @ 2.5 L ha-1 are recommended for achieving higher onionyield. However, manual weeding may not be feasible and economical inthe large onion cultivations.