Rice breeding in retrospect

Abstract

Crop science harmonizes genetic improvement with crop husbandry. Rice yields in the temperate regions were higher than in the tropics due to this synergism. The turning point for elevation of rice yields in the tropics was the genetic improvement based on plant type. The yield potential of tropical rice was nearly doubled with the development of semi-dwarf cultivars. These cultivars have successfully elevated the plane of crop husbandry, at least as reflected in the rate of fertilizer use. A national grid of genetic improvement was in place by the mid-1960s with the object of incorporating the plant type attributes into the locally grown and consumer-accepted cultivars. The elevation of yield potential, which was convincing from Taichung (Native)-1 to IR 8, and thereon to Jaya, seemed to have been stalled. The change in the plant type of cultivars had its impact on the status and severity of insect or disease pressures on the rice crop. Improved technology may contribute either to efficiency in production or to convenience in farming. The acid test for any technology is the reduction in cost of the produce. Development is compelled to be opportunistic, merely selecting among existing possibilities. Science, in contrast, is expected to be creative and to expand the realm of possibilities. Production breeding aimed at an elevation in yield potential was sidetracked due to competing priorities for consumer-preferred grain quality and for resistance to biotic and abiotic stresses. The national concern regarding rice in the 1950s was the expansion in production. This concern was changed in the 1970s to factor productivity for land, water and time. Contemporary concern is profitability of rice farming. This shift in priority from production to productivity, and then on to profitability is an index of progress with technology. It is also the continuing challenge for the future.