Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 13, 1997
Publication Date: N/A
Interpretive Summary: Rice cultivars differ in their yield ability due to inherent traits as well as their response to external, environmental factors. The Asian cultivar, 'Teqing', is able to produce very high yields through production of additional tillers late into the season. This is in contrast to the U.S. cultivar Gulfmont' which produced fewer tillers but in a shorter period. Analysis of yield components like tillering ability will allow breeders to identify which traits have the greatest impact on total yield and can be manipulated to develop improved cultivars. An understanding of how yield components respond to different edaphic stresses will also allow breeders to develop high yielding cultivars for specific environmental conditions.
Field experiments were conducted to evaluate the effect of cultivar and plant density on the growth and development of rice (Oryza sativa L.),and the contribution of successively produced tillers to grain yield. Both cultivar ( Gulfmont', 'Rosemont'and Teqing') and plant density significantly affected node production rate, tiller height, tillering production, panicle density, number of spikelets per panicle, percentage o filled spikelets, and kernel weight. Grain yield was significantly affected by cultivar, but not by plant density. The higher yield of Teqing appears largely to have resulted from its greater tillering ability, higher spikelet density, and a greater use of season length. Dry matter partitioning among tillers was a function of plant density and each cultivar's tillering ability. Cultivars with a high tillering ability partitioned more mass to subtillers, especially at low plant densities.