Abstract
Eight experiments on direct wet-seeding using drum seeder and transplanting were carried out at the Bangladesh Rice Research Institute experimental farm and the Laboratory, Gazipur during June 2004 to December 2005 to find out the effect of different management practices viz. rice variety, seed soaking and incubation period, direct wet seeded (DWSR) by drum. seeder, transplanting (TPR), date of seeding, herbicide (Ronstar) application on the growth and yield of Aman, Boro and Aus rice. Results showed that the longest radicle and plumule were produced at 12 and 24 hours soaked with 96 hours incubation, respectively in Aman season, while 24 and 36 hours soaked with 96 hours incubation, respectively in Boro season. Seed rate was reduced when sown by drum seeder with the increase of seed incubation period. The highest and the lowest grain yield were found at 72 and 96 hours of seed incubation, respectively in Boro season while at 96 and 72 hours in Aman season. Direct wet- seeded rice by drum seeder reduced 8-12 days growth duration than transplanted rice. DWSR gave 88% higher number of panicles m2, 16% less grains panicle and 10% higher grain yield than TPR. The highest grain yield was found when the crop was planted on 31 December. The lowest number of seedlings was emerged when herbicide was applied at 3 days after seeding (DAS) @ 2.0 1 ha' in Boro season and 3 DAS @ 1.5 I ha in Aus season. The lowest and the highest grain yield were recorded when herbicide was applied at 3 DAS @ 1.5 I ha and 6 DAS @ 1.5 I ha', respectively in Boro season while in unweeded and weed free plots, respectively in Aus season. Higher weed biomass was found in unweeded plots and no weed was produced in herbicide treated plots at 20 DAS in Boro season while unweeded and weed free plots in Aus season. BRRI dhan27 produced higher culm strength than BR26 at 80 and 100 DAS. TPR gave higher culm strength than DWSR at 80 and 100 DAS. DWSR gave lower culm strength, longer root than TPR. Direct wet-seeded method produced higher plant height than transplanted method in Aus season.