Abstract

                                A field experiment was conducted in dry seeded bunded rice for two seasons ot Tamil Nadu Agricultural University. Coimbatore. The intensity of annual grass Echinochloa colonum during the first and second monsoon was 52 and 165/sq.m under moderately clay soil with 1.3 per cent organic matter. Either individual appli- cation of herbicides viz. butachlor 1.0 kg ai/ha, thiobencarb 1.0 kg ai/ha and pendimethalin 0.75 kg ai/ha at 8 d.a.s or as mixture with propanil 2.00 kg ai/ha at 16 d.a s was effective in controlling the above grass weed and recorded low weed dry matter production. Eighth day application of pendimethalin gave higher mean grain yield of 4012 kg/ha. It was on par with butachior, thiobencarb applied on eigth day and herbicides mixtures at 16 das and superior to twelfth day appli- cation of herbicides.

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