Field Performance of Selected Hybrid Rice at Five Louisiana Locations.

In the southern United States, hybrid rice (Oryza sativa L.) acreage has been rapidly increasing since its first commercialization in 2000 by RiceTec Inc. There is very limited public information on the yield advantage of hybrid rice over inbred cultivars under southern U.S. conditions. Therefore, a field research was conducted at five Louisiana locations during 2006 and 2007 to evaluate the grain yield, milling quality, maturity, plant height, reactions to diseases, and lodging susceptibility of latest hybrids, along with leading commercial inbred rice cultivars. Our results indicated that hybrid rice had a significant grain yield advantage over inbred cultivars. In 2006, the average yield of the four hybrids (CLXL8, XL723, CLXL730, and XP729) was 9.97 Mt ha^-1 compared with the averaged 8.34 Mt ha^-1 for long-grain inbred cultivars. A similar yield advantage was observed in 2007 when the average grain yield of five hybrids (CLXL729, CLXL730, CLXP745, XL723, and XP744) was 9.87 Mt ha^-1 compared with 7.32 Mt ha^-1 for inbred cultivars. The hybrids had a significantly lower whole rice yield than the inbred cultivars, even though the total milled rice yield was similar between the two. The average whole milled rice yields of hybrids were 598 and 580 g kg^-1 compared with 632 and 599 g kg^-1 for inbred cultivars for 2006 and 2007, respectively. Hybrid rice had similar maturity but was significantly taller than inbred cultivars. The average plant heights of hybrids were 110 and 117 cm compared with 93 and 97 cm for inbred long-grain cultivars for 2006 and 2007, respectively. Hybrid rice was susceptible to lodging with an average incidence of 26%. Nevertheless, hybrid rice had better resistance to both sheath blight and bacterial panicle blight.