Evaluation of Combination Weedicides in Transplanted Rice

A field experiment was conducted during Rabi 2003–04 and Kharif 2004 with objectives of testing the combination weedicies in different dosages and time of application in transplanted rice for weed control efficiency and their impact on growth and grain yield of rice. The herbicidal treatments comprised triasulfuron alone @ 0.006–0.012 kg a.i/ha and in combination with pretilachlor @ 0.450 and 0.600 kg a.i./ha and, almix+butachlor @ 0.004+0.938 kg a.i/ha along with weed-free check, hand weeding twice and non-weeded control. Pretilachlor @0.600 kg a.i./ha (3–5 DAT) was found effective against grassy weeds. Triasulfuron @ 0.009 kg a.i./ha (12–15 DAT) exhibited significant efficacy against broad leaved weeds (BLW); however under low moisture conditions, the higher dose @ 0.012 kg a.i./ha was found to be toxic to rice crop. Broadspectrum weed control against grassy as well as BLW was observed due to application of combination herbicides triasulfuron+pretilachlor@ 0.009+0.045 kg a.i./h as well as almix+butachlor @ 0.004+0.938 kg a.i./ha (3–5 DAT)and were comparable to two hand weedings or weed- free check treatments.