Effect of transplanting and direct seeding on tillering, crop growth, and yield of lowland rice [Philippines].
1988
Javellana C.B. | Dingkuhn M. | Schnier H.F. | Marqueses E. | Faronilo J. | Wijangco E. | De Datta S.K.
Transplanting and direct seeding effects on tiller production, leaf area index [LAI], crop growth rates, dry matter accumulation, and grain yield were evaluated. Seeding techniques markedly affected growth kinetics. Direct seeding enhanced crop establishment and vegetative growth and reduced crop duration by 2 weeks. High tillering and leaf area formation during vegetative stage increased yield potential but posed nutritional problems: fast initial growth in direct seeded rice led to high N demand and an N dilution effect in the tissues, resulting to substantially lower N concentrations in the shoot before and during PI [panicle initiation]. Maintenance of grain yield potential was strengthened through high N dosage before PI. Maximum canopy photosynthesis was highly correlated with leaf N content at a given LAI. At higher leaf N content (vegetative stage), high LAI favored assimilation, at leaf N below 1% (ripening stage), high LAI reduced assimilation. Prevention of excessive tillering through proper N application timing improved source-sink relationships during ripening stage in direct-seeded rice. Grain yield was generally high. Direct seeded rice produced higher grain yield than transplanted rice. Yield differences among the treatments were significant. Highest grain yield obtained (8.5 t/ha, 8 replications) was a result of low N losses, split N application, and direct seeding technique (hill-wise dibbling).
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