ONE OF THE important considerations in the development of any new rice variety is its optimum range of seeding dates. The response to seeding date of present commercial rice varieties in California is well known, hut must be determined for new and introduced varieties. The commercial rice crop in California is sown directly into the water. In the past, however, the rice-breeding nurseries have been drilled rather than water-seeded. Recent studies have demonstrated that rice sown directly into the water produces higher yields than rice that is drilled.

This is a progress report of cooperative investigations of the Crops Research Division, ARS, USDA; Dept. of Agronomy, University of California; and the California Cooperative Ricr Research Foundation.