Bangladesh, a country with heavy population pressure on its limited land resources, has made notable progress in achieving food security by cultivating modern varieties (MVs) of rice notwithstanding the continuous depletion of arable land. The achievement must have surprised the critiques of the green revolution. The early green revolution advocates argued that only the large and more commercialised farms having access to information and formal credit market or enough savings from farm operations would be able to adopt high-yielding varieties.
In Bangladesh 60 per cent are tenants who get land mostly under the share cropping arrangement. In view of the slow technological progress in 1970s several influential rural studies argued that the agrarian structure would constrain the development of productive forces in Bangladesh's agriculture. But the MVs now are cultivated on about 65 per cent of the rice farming areas, with the support like irrigation through shallow tube-wells and power pumps. An analysis of the factors contributing to the diffusion of modern varieties in Bangladesh may help answer the question whether it is the agrarian structure or appropriate policy that impedes green revolution.
The rice researchers in Bangladesh are coming up with new generation varieties of the crop. To what extent the farmers are switching over from the "old" improved varieties to the "new" ones and what has been the impact of the new generation varieties are issues not yet studied rigorously. Addressing these issues is important for assessing the capacity of the researchers to sustain the food security for the growing population, as the adoption of modern varieties is reaching the plateau, particularly because of the favourable rice growing environment. The major achievement of the rice research system in Bangladesh, as in other Asian countries, has been the development of improved varieties. By 2001 the Bangladesh Rice Research Institute (BRRI) released 40 rice varieties for different agro-ecological conditions. The number of varieties released in the 1990s was 16 compared with 13 in the 1980s and nine in the 1970s.
Almost half the varieties released by the BRRI for the dry season are of the advanced lines developed at the International Rice Research Institute (IRRI) or other national agricultural research facilities. They were tested under the International Network for Genetic Evaluation of Rice (INGER) programme and found suitable for Bangladesh. But for the wet season the crosses for most of the varieties were developed by the BRRI. The experience indicates that for the irrigated ecosystem countries can depend on international spillover of technologies as good water control makes them widely adaptable. However, for the less favourable rain-fed ecosystem, breeding needs to be done locally to take care of the location-specific, agro-ecological and climatic conditions.
The new-generation varieties did not in general have higher yield potential like the traditional ones. For the dry season the yield of BR3 released in 1973 was surpassed only by BRRI Dhan 28 and 29, both of them were released in 1994. For the wet season the potential yield of BR11 released in 1981 has not yet been surpassed by any new variety, although 11 varieties have been released since then.
Rice breeders looked for other traits than yield, such as resistance to insects and diseases, grain quality, plant height and growth duration in deciding on release of a new variety. The varieties released in 1970s had medium resistance to the tungro virus but were susceptible to most other diseases and insects. The varieties released in 1980s have better resistance to yellow stemborer, leaf blight and blast and mild resistance to brown plant hopper and sheath blight. In the 1990s the traits of variable growth duration and plant height were given higher priority in the decision on releasing a variety. Many varieties released in 1990s have shorter plant height, better grain quality and shorter maturity period than the varieties released in the 1970s. The shorter maturity varieties helped farmers fit non-rice crops in the rice-based farming systems to improve cropping intensity and increase the yield of the subsequent non-rice crops.
The writer is Professor of Economics at Jahangirnagar University.
 abdulbayes@yahoo.com
Of rice varieties
Abdul Bayes | Published: March 21, 2015 00:00:00 | Updated: November 30, 2024 06:01:00
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