This study was carried out to determine the optimum seeding date for the rice(Oryza sativa L.) cultivation of the puddled-soil drill seeding, which is one of the efficient labor saving cultural methods, at the central part of Korea. Namweonbyeo, Anjun...
This study was carried out to determine the optimum seeding date for the rice(Oryza sativa L.) cultivation of the puddled-soil drill seeding, which is one of the efficient labor saving cultural methods, at the central part of Korea. Namweonbyeo, Anjungbyeo and Ilpumbyeo were seeded on four dates from April 10 to May 25, 1994 with the 15 day interval in the paddy field. In order to examine the adequate seeding date, the growth characters, yield components and yields were investigated. The coleoptile emerged 1 or 2 days earlier in Namweonbyeo than in Anjungbyeo and Ilpumbyeo, and later seeding resulted earlier coleoptile emergence. The number of seedling stands were higher in the order of Namweonbyeo, Anjungbyeo and Ilpumbyeo, was increased at the later seeding and was 81 to 88 seedlings on April 10 seeding. The plant height, number of leaves, number of tillers and dry weight at 50 days after seeding of all three cultivars were higher at later seeding. Leaf area index(LAI) were higher in the order of Ilpumbyeo, Anjungbyeo and Namweonbyeo. LAIs at the heading stage, at 30 days after heading and at 30 days before heading were higher in that order. The dry matter weight at the 30 days before heading was higher in sheath and stem than that in leaf blade, while, at heading stage, it was higher in the order of sheath and stem, leaf blade and panicle. On the other hand, at 30 days after heading, it was higher in the order of panicle, sheath and stem and leaf blade. The number of panicles per m2 was greater in the order of Ilpumbyeo, Anjungbyeo and Namweonbyeo. The ratio of ripened grain was reduced as the later seeding date. Its ratio was higher in Namweonbyeo than in Anjungbyeo and Ilpumbyeo. Yield of Namweonbyeo was lower than those of Anjungbyeo and Ilpumbyeo. Yield was decreased as the seeding date was delayed. Namweonbyeo showed the highest yield at seeding on May 10, while Anjungbyeo and Ilpumbyeo showed at seeding on April 25. The seeding date was negatively correlated with the ratio of ripened grain. while the number of seedling stands was positively correlated with the number of panicle per m2.