Mahabub HOSSAIN
Social Sciences Division, International Rice Research Institute, Metro Manila, Philippines
Manik L. BOSE
Social Sciences Division, International Rice Research Institute, Metro Manila, Philippines
Bazlul A. A. MUSTAFI
Agricultural Economics Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh
Variety replacement; Technological progress; Productive efficiency; Unitcosts; Bangladesh
Socio-economic and Policy
Adoption of technology
In Bangladesh, rice is grown in three overlapping seasons. The monsoon rice, “aman,”harvested in November–December is the main rice crop. It occupied 5.7 million hectares in 2002/03, approximately 53%of the total rice area. On land with shallow flooding depth aman is transplanted with shorter duration varieties, but on deep-flooded land aman is directly seeded as an upland crop from March to May. Then the plant grows with floodwater from June to September, and is harvested in November after the floodwater recedes. Bangladesh receives about 400 millimeters of rain during the pre-monsoon months of March to May, which farmers use to grow a short-duration drought-resistant crop known as “aus,”which gives an yield of about 1.8 t/ha. The crop is mostly directly seeded during March–April and harvested in July–August. In 1969/70 the crop occupied 3.4 million hectares, but the area has declined to 1.2 million hectares by 2002/03, as farmers shifted the land to vegetables or dry season irrigated rice called“boro”. Boro was used to be grown in very lowing land (not suitable for growing any crop during the monsoon season), transplanted in November after the recession of the flood and harvested in April–May. However, with the spread of the ground water irrigation, the area has expanded to all land types, and is now mostly transplanted in January–February and harvested in May–June. The area has expanded from 0.5million hectares in 1969/70 to 3.8 million hectares in 2002/3, which is 35% of the total rice area. Since aus and boro are overlapping crops, for the purpose of the current paper we have classified the seasons into two: wet (aman) and dry (boro and aus). Bangladesh Rice Research Institute (BRRI) is the main organization responsible for rice research. The Bangladesh Institute of Nuclear Agriculture (BINA), the Bangladesh Agricultural University (BAU), Mymensingh, and the botany and biochemistry departments of various universities do basic and strategic research, but their contribution to developing improved varieties has remained marginal. A. Production of Varieties The major achievement of the rice research system in Bangladesh, as in other Asian countries, has been the development of improved varieties. By 2001, BRRI had released40 rice varieties for different agroecological conditions, whereas BINA and BAU had released six (Miah 1989; Islam and Rabbi 2002; BRRI 2003). Table 1 reports the characteristics of the rice varieties produced by BRRI. The production of improved varieties has been continuing. The number of varieties released in the 1990s was16, compared with 13 in the 1980s, and nine in the 1970s. The following major points about the production of MV in Bangladesh can be noted from the table. Almost half of the varieties released by BRRI for the dry season are advanced lines developed at IRRI or other national agricultural research systems and found suitable for Bangladesh when tested under the International Network for Genetic Evaluation of Rice (INGER). However, the crosses for most of the varieties for the wet season were made by BRRI. It shows that for the irrigated ecosystem, the countries can depend on an international spillover of technologies (Evenson and Gollin 1997) as good water control makes them widely adaptable. However, for the less favorable rainfed ecosystem, breeding needs to be done locally to take care of the location-specific agroecological and climatic conditions.Breeders looked for traits other than yield, such as resistance to insects and diseases,grain quality, plant height, and growth duration when deciding to release a new variety(Miah 1989). Varieties released in the 1970s had medium resistance to the tungro virus, but were susceptible to most other diseases and insects. The varieties released in the 1980s had better resistance to yellow stem borer, leaf blight, and blast, along with a mild resistance to brown plant hopper and sheath blight (Miah 1989; Shahjahan1993; BRRI 2003). In the 1990s, the traits of variable growth duration and plant height were given higher priority in the variety release decisions in order to suit parcels of land located in different elevations (which determine duration of moisture availability and flooding depth). Many varieties released in the 1990s have shorter plant height, better grain quality, and a shorter maturity period than the varieties released in the 1970s. The shorter maturity varieties helped farmers to fit non-rice crops in the rice-based farming systems, enabling farmers to both improve cropping intensity and increase yield in subsequent non-rice crops, such as wheat.
The Developing Economies, XLIV-2 (June 2006): 149 – 66
Journal