Effect of time of application of butachlor and oxyfluorfen on direct-sown rice on puddled soils

摘要

A field experiment was conducted during the wet seasons-of 1993 and 1994 to find out a suitable herbicide and its time of application for effective weed control in direct-sown rice on puddled soil, Highest grain yield of 5.941 ha~(-1) was recorded with butachlor at 1.5 kg ha~(-1) applied one day before sowing which was comparable with its spray on the day of sowing and one day after sowing. The lowest grain yield (1.04 t ha~(-1) ) was obtained in the weedy check. The herbicide oxyfluorfen at 0.15 kgha~(-1) applied 7 days after sowing increased the grain yield to an extent of 31 and 63% over that applied one day before sowing and weedy check, respectively, Weed control efficiency for both oxyfluorfen and butachlor applied one day before sowing was almost the same. However, grain yield was substantially reduced when oxyfluorfen was applied one day before sowing due to its phytotoxic effects on germinating rice seedlings.