High-yielding rice cultivars in U.S.
1989
Bollich, C.N. | Rutger, J.N. | Brandon, D.M. (USA. Department of Agriculture. Agricultural Research Service)
Rice production in the U.S. is highly mechanized; all rice is direct-seeded and irrigated. Yields on a total of 1 million ha average about 6t/ha. Characteristics that contribute to high yields include lodging resistance, early maturing and disease resistance. Lodging resistance and associated N-responsiveness of new cultivars have had the largest effect on yield. Lodging resistance has been achieved by breeding for short stature, through quantitative gene action and through the major semidwarfing gene sd 1. The semidwarfs (which have been studied most) produce 15-25% higher yields due to a combination of improved lodging resistance and production of more panicles/unit area. Additional physiological characteristics that can raise yield levels further have not yet been defined adequately for rice breeders to put them to work in breeding new cultivars.
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