Contents & Foreword, Characterizing And ... - IRRI books

Insects and diseasesInsects and diseases reduce rice yield. Intensification in rice production has changedthe types and pressures of many insects and diseases. Although insects and diseasescan be controlled with appropriate management techniques, their pressures need to becharacterized and classified, at least for varietal improvement activities. The use ofresistant varieties is still the cheapest and most effective measure for controlling insectsand diseases in rice.Socioeconomic issuesAlthough an area may be suitable for rice production based on ecological environments,rice production may not necessarily be the best suited based on socioeconomics.Many areas suitable to rice production in southern Brazil, Argentina, and Venezuelaare either planted to other crops or under fallow due to the high costs of rice productionand irrigation infrastructure. With the globalization of the world economy, riceproduction needs to be evaluated for its competitiveness not only with rice productionin other areas but also with the production of other crops in the same area.The costs of providing favorable conditions for rice production such as irrigationinfrastructure, an adequate supply of inputs and credit, and better marketing ofrice need to be included in characterization. It is well known that improved rice technologies,such as high-yielding varieties, could not make a significant contributionwithout the adequate availability of production inputs. The yield of IR8 does notdiffer significantly from that of its parent, Peta, unless fertilizers are applied.The labor force for rice production in many countries has been shrinking rapidlydue to a combination of population control, improvement in income, and employmentopportunities created to improve national economies. Also, in many countries,the population of rice farmers has become older and older because of the migrationof young people to urban centers and job preferences. The scarcity of labor andhigh rural wages have led to a shift in the application of rice technologies in thesecountries. Land preparation, harvesting, and threshing operations have become moreand more mechanized, direct seeding has increasingly replaced transplanting as themain crop establishment method, and chemical weeding has become more popularthan hand weeding. In countries such as India, the Philippines, and Thailand, womenhave been participating more and more actively in rice production operations.Socioeconomic factors vary with changes in the national economy. Understandingsocioeconomic factors could have an important bearing on activities aimed atdeveloping new rice land and at creating the appropriate conditions for adopting improvedtechnologies. Socioeconomic factors were considered as major constraints tothe agricultural development of inland valleys in West Africa (Table 6).Global climate changeGlobal climate change has been increasingly observed. The global climate has warmedbecause of the emission of CO 2 and other gases such as methane and nitrite oxide andtheir accumulation in the atmosphere. Temperature and CO 2 concentration are importantparameters of the photosynthetic pathway, whereas temperature influences respi-46 Van Nguu Nguyen