Promoting appropriate rice technology
Wednesday, 11 January 2012
Abdul Bayes
It is now a widely accepted view that there is no substitute of the spread of modern technology in paddy cultivation for sustainable food security in Bangladesh. About 150 million people live in this country -- 920 persons per km2 -- and per capita land base is pitifully low at only 0.061 ha. The good news is that population growth has declined from 3.0 to 1.5 per cent per year over the last three decades.
But while celebrating this success, we should be a little bit cautious about the complacency since the nation's population continues to grow by two million every year to join the already existing 'human sea'. Besides, the per capita income is extremely low (US$ 600 in 2008) and as economic theory postulates, nearly 60 per cent of the earned income is spent on food (rice alone claims 30 per cent.). At present, paddy accounts for three-fourths of the total cultivated area.
Quite obviously, it is very urgent to get more paddy out of the given amount of land as; otherwise, there will be shortage of land for producing income-elastic commodities -- the demand for which rises in tandem with income. And we know it well that, since the 1980s, rapid urbanisation and a satisfactory growth in per capita income has fueled the demand for non-paddy crops.
Indeed, Bangladesh has made remarkable progress in sustaining a respectable growth of paddy production over the last three decades. It has come through the adoption of modern varieties (MVs). But it must also be remembered that this spectacular success came on the heels of falling cultivable land and pervasive presence of agricultural labour. Several influential rural studies in the 1970s had opined that the main hurdle on the way of the emergence of development forces in Bangladesh's agriculture is the existing agrarian.
But unhesitatingly it can be argued now that the apprehension has been proved wrong on account of the praiseworthy progress during the past days. With the help of mechanised irrigation, MVs are now spread over two-thirds of the cultivated land. More importantly, the glaring success in paddy production sprang from the adoption of high yielding varities (HYVs) at the cost of traditional and low-yielding ones (TVs).
Ongoing rice research has been producing new generations of modern varieties. But rigorous research is yet to come up with answers to the questions: to what extent have farmers been changing from the "old" improved varieties to the "new" ones, or, what have been the impacts of the new generations of modern varieties? Addressing such issues is very important for assessing the capacity of the research system to sustain the growth in rice production in the future. It may be noted here that, in favourable paddy-growing environment, the yield levels of modern varieties have already reached the plateau.
In Bangladesh, paddy is grown in three overlapping seasons. The main paddy crop Aman - called wet season crop - is harvested in the months of November-December. This crop used to occupy an area of roughly 6.0 million ha or, 57 per cent of total paddy lands in 2002-03. In lands with shallow depth of flooding, 'Aman' of shorter duration is planted but, in deep-flooded lands, 'Aman' is directly seeded from March to May. Later, the plant grows with floodwater from June to September, and is harvested in November after floodwater recedes. En passant, Bangladesh receives about 400 mm of rain during the pre-monsoon months of March to May and at this time the farmers grow a short-duration and drought-resistant crop known as 'Aus" (henceforth Aus). The yield of Aus is about 1.8 tons/ha. The crop is mostly directly seeded during March-April and harvested in July-August. In 1969/70, the crop occupied 3.4 m ha, but in 2002/03, Aus was grown in 1.2 m ha. This means a decline in Aus area by three times and the farmers began to use the 'lost' land either for growing vegetables or irrigated Boro-paddy.
In our country, once 'Boro' paddy used to be grown in very low land - land not suitable for growing any crop during the monsoon season. The transplantation used to take place in November after the recession of the flood and the crop used to be harvested in April-May. But, with the spread of the ground water irrigation and until today, 'Boro' paddy is being cultivated in all types of lands. This crop is now transplanted mostly in January-February and the crop is harvested in May-June. By 2002/03, 'Boro' paddy occupied 35 per cent of the total paddy area. Since 'Aus' and 'Boro' are overlapping crops, for the purpose of this write-up we have classified the seasons into two broad heads: wet ('Aman') and dry ('Boro' and 'Aus').
The main institutions for rice research in our country are Bangladesh Rice Research Institute (BRRI), the Bangladesh Institute of Nuclear Agriculture (BINA) and, the Bangladesh Agricultural University (BAU), Mymen-singh. Besides, the botany and biochemistry departments of various universities conduct basic and strategic research but their contribution to developing improved varieties has remained marginal.
The major achievement of the rice research in Bangladesh, as in other Asian countries, has been the introduction of improved varieties. By 2001, BRRI had released 40 rice varieties for different agro-ecological conditions while BINA and BAU had released six varieties. The characteristics of the rice varieties produced by BRRI sheds some interesting insights. The production of improved varieties has been continuing and, for example, the number of varieties released in the 1990s was 16, compared to 13 in the 1980s, and nine in the 1970s.
Almost half of the varieties released by BRRI apply for the dry season. These are advanced lines developed at IRRI and other national agricultural research systems, and found suitable for Bangladesh when tested under the International Network for Genetic Evaluation of Rice (INGER). On the other hand, 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 international spill-over effects 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.
Before releasing in the market, breeders have looked not only for yield but also for traits such as resistance to insects and diseases, grain quality, plant height, and growth duration. For e.g. varieties released in the '70s had medium resistance to tungro virus, but had no capacity to resist most other diseases and insects. The varieties released in 1980s had better resistance to yellow stemborer, leaf blight, and blast, along with a 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 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 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 produce non-rice crops in the rice-based farming systems and, thus, enabling them to improve cropping intensity and increase yield in subsequent non-rice crops, such as wheat.
It is often observed that, in the face of insects and diseases, a new variety is released to replace an old variety. But there is no guarantee that the new variety will surely be high yielding variety or its yield level would be higher. The early variety for the dry season that had the highest yield was BR-3 released in 1973. The yield potential of this variety was surpassed only in 1994 with the release of Brridhan29 (BR-29) demonstrating an average yield of 7.5 tons/ha in multi-location trials. On the other hand, the variety that gave the highest yield for the Aman season, BR-11, was released in 1980.
The writer is a Professor of Economics at Jahangirnagar University. He can be reached at e-mail: abdulbayes@yahoo.com
It is now a widely accepted view that there is no substitute of the spread of modern technology in paddy cultivation for sustainable food security in Bangladesh. About 150 million people live in this country -- 920 persons per km2 -- and per capita land base is pitifully low at only 0.061 ha. The good news is that population growth has declined from 3.0 to 1.5 per cent per year over the last three decades.
But while celebrating this success, we should be a little bit cautious about the complacency since the nation's population continues to grow by two million every year to join the already existing 'human sea'. Besides, the per capita income is extremely low (US$ 600 in 2008) and as economic theory postulates, nearly 60 per cent of the earned income is spent on food (rice alone claims 30 per cent.). At present, paddy accounts for three-fourths of the total cultivated area.
Quite obviously, it is very urgent to get more paddy out of the given amount of land as; otherwise, there will be shortage of land for producing income-elastic commodities -- the demand for which rises in tandem with income. And we know it well that, since the 1980s, rapid urbanisation and a satisfactory growth in per capita income has fueled the demand for non-paddy crops.
Indeed, Bangladesh has made remarkable progress in sustaining a respectable growth of paddy production over the last three decades. It has come through the adoption of modern varieties (MVs). But it must also be remembered that this spectacular success came on the heels of falling cultivable land and pervasive presence of agricultural labour. Several influential rural studies in the 1970s had opined that the main hurdle on the way of the emergence of development forces in Bangladesh's agriculture is the existing agrarian.
But unhesitatingly it can be argued now that the apprehension has been proved wrong on account of the praiseworthy progress during the past days. With the help of mechanised irrigation, MVs are now spread over two-thirds of the cultivated land. More importantly, the glaring success in paddy production sprang from the adoption of high yielding varities (HYVs) at the cost of traditional and low-yielding ones (TVs).
Ongoing rice research has been producing new generations of modern varieties. But rigorous research is yet to come up with answers to the questions: to what extent have farmers been changing from the "old" improved varieties to the "new" ones, or, what have been the impacts of the new generations of modern varieties? Addressing such issues is very important for assessing the capacity of the research system to sustain the growth in rice production in the future. It may be noted here that, in favourable paddy-growing environment, the yield levels of modern varieties have already reached the plateau.
In Bangladesh, paddy is grown in three overlapping seasons. The main paddy crop Aman - called wet season crop - is harvested in the months of November-December. This crop used to occupy an area of roughly 6.0 million ha or, 57 per cent of total paddy lands in 2002-03. In lands with shallow depth of flooding, 'Aman' of shorter duration is planted but, in deep-flooded lands, 'Aman' is directly seeded from March to May. Later, the plant grows with floodwater from June to September, and is harvested in November after floodwater recedes. En passant, Bangladesh receives about 400 mm of rain during the pre-monsoon months of March to May and at this time the farmers grow a short-duration and drought-resistant crop known as 'Aus" (henceforth Aus). The yield of Aus is about 1.8 tons/ha. The crop is mostly directly seeded during March-April and harvested in July-August. In 1969/70, the crop occupied 3.4 m ha, but in 2002/03, Aus was grown in 1.2 m ha. This means a decline in Aus area by three times and the farmers began to use the 'lost' land either for growing vegetables or irrigated Boro-paddy.
In our country, once 'Boro' paddy used to be grown in very low land - land not suitable for growing any crop during the monsoon season. The transplantation used to take place in November after the recession of the flood and the crop used to be harvested in April-May. But, with the spread of the ground water irrigation and until today, 'Boro' paddy is being cultivated in all types of lands. This crop is now transplanted mostly in January-February and the crop is harvested in May-June. By 2002/03, 'Boro' paddy occupied 35 per cent of the total paddy area. Since 'Aus' and 'Boro' are overlapping crops, for the purpose of this write-up we have classified the seasons into two broad heads: wet ('Aman') and dry ('Boro' and 'Aus').
The main institutions for rice research in our country are Bangladesh Rice Research Institute (BRRI), the Bangladesh Institute of Nuclear Agriculture (BINA) and, the Bangladesh Agricultural University (BAU), Mymen-singh. Besides, the botany and biochemistry departments of various universities conduct basic and strategic research but their contribution to developing improved varieties has remained marginal.
The major achievement of the rice research in Bangladesh, as in other Asian countries, has been the introduction of improved varieties. By 2001, BRRI had released 40 rice varieties for different agro-ecological conditions while BINA and BAU had released six varieties. The characteristics of the rice varieties produced by BRRI sheds some interesting insights. The production of improved varieties has been continuing and, for example, the number of varieties released in the 1990s was 16, compared to 13 in the 1980s, and nine in the 1970s.
Almost half of the varieties released by BRRI apply for the dry season. These are advanced lines developed at IRRI and other national agricultural research systems, and found suitable for Bangladesh when tested under the International Network for Genetic Evaluation of Rice (INGER). On the other hand, 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 international spill-over effects 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.
Before releasing in the market, breeders have looked not only for yield but also for traits such as resistance to insects and diseases, grain quality, plant height, and growth duration. For e.g. varieties released in the '70s had medium resistance to tungro virus, but had no capacity to resist most other diseases and insects. The varieties released in 1980s had better resistance to yellow stemborer, leaf blight, and blast, along with a 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 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 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 produce non-rice crops in the rice-based farming systems and, thus, enabling them to improve cropping intensity and increase yield in subsequent non-rice crops, such as wheat.
It is often observed that, in the face of insects and diseases, a new variety is released to replace an old variety. But there is no guarantee that the new variety will surely be high yielding variety or its yield level would be higher. The early variety for the dry season that had the highest yield was BR-3 released in 1973. The yield potential of this variety was surpassed only in 1994 with the release of Brridhan29 (BR-29) demonstrating an average yield of 7.5 tons/ha in multi-location trials. On the other hand, the variety that gave the highest yield for the Aman season, BR-11, was released in 1980.
The writer is a Professor of Economics at Jahangirnagar University. He can be reached at e-mail: abdulbayes@yahoo.com