278-4 Yield and Yield Components of Southern Long- and Medium-Grain Rice As Affected By Planting Dates and Seeding Rates.
Poster Number 532
See more from this Division: C01 Crop Breeding & GeneticsSee more from this Session: Crop Breeding and Genetics: IV
Our results indicated that yield reductions of both long- and medium-grain rice after the recommended planting date primarily resulted from a lower number of panicles per unit area, lighter grain weight, and to the less extend, fewer filled grains per panicle. The average number of panicles per square meter was 311, 349, and 356 for the mid-May, mid-March, and late-April planting dates, respectively. The mean grain weight from the mid-May planting was 23.5 mg, while the mid-April and mid-March planting had mean grain weight of 25.0 mg and 25.5 mg, respectively. The highest average number of spikelet per panicle was observed at mid-May planting dates followed by mid-March and mid-April dates; however, grain fertility decreased as planting date was delayed. Average seed set for the mid-March planting dates was the highest at 78.5%, while that for mid-May plantings was only 71.4%. The 1.5X recommended seeding rate failed to produce higher grain yields than the normal seeding rate for the mid-May planting dates. The 50% of additional seed only added 6.8% more panicles (350 m-2 vs 327 m-2).
See more from this Session: Crop Breeding and Genetics: IV