Rice

Abstract

As one of the world's most important food crops, rice (Oryza sativa L.) is produced in a mechanized direct-seeded production system in the United States, in contrast to a transplanted production system in Asia, where most of the world's rice is grown and consumed. The United States is a major rice exporting country but accounts for less than 1% of the world's production. From 1981 to 2011, U.S. rice yields increased 86 kg ha-1 yr-1 to a 3-yr national average of 7.8 t ha-1. U.S. rice is produced in a southern region including Arkansas, Louisiana, Mississippi, Texas, and Missouri and in a second region in the central valley of California. Yield levels, and the rate and time period of yield increases, have varied among the U.S. rice-growing regions. To ascertain the genetic yield gain and realized maximum yields, regional data from rice breeding programs in Louisiana, Arkansas, and California were analyzed and values were estimated. Results confirmed the difference in the genetic yield gain, with Louisiana achieving 87 kg ha-1 yr-1 and reaching 7.1 t ha-1 and California achieving 25 kg ha-1 yr-1 and reaching 9.3 t ha-1. Future prospects for U.S. rice yield enhancement, including the role that hybrid or transgenic rice might play, and obstacles to continued progress like grain quality and environmental and regulatory issues are discussed.