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Krishna Joshi

Krishna Joshi explains how COB has been developed in Nepal, India and Bangladesh
Krishna Joshi explains how COB has been developed in Nepal, India and Bangladesh

Client-oriented breeding (COB): bridging yield gaps and addressing food and income security

Krishna Joshi is Research Co-ordinator for the DFID Plant Sciences Research Programme.

The contributions of plant breeding over the last one hundred years cannot be underestimated, particularly the tremendous impact of the green revolution for many farmers across the Asian continent, who now grow and benefit from high-yielding varieties. However, these varieties have largely contributed to the livelihoods of those farming in high production systems where farmers have access to irrigation, roads and markets, and they can afford to buy good quality seed, chemicals and fertilisers. For poor farmers in low-input rainfed, marginal areas, high yielding varieties produced by conventional breeding are neither appropriate nor adapted to their needs. Consequently, the majority of poor farmers continue to grow old varieties that are often susceptible to pests and diseases.

One means of addressing this problem is to place the seed of novel cultivars directly into the hands of farmers so that they have the opportunity to test new cultivars for themselves under their own field conditions. By promoting partnership between researchers and farmers, the DFID-funded Plant Sciences Research Programme has developed an alternative approach to conventional plant breeding; known as COB or PPB (client-oriented or participatory plant breeding), which targets the breeding programme to meet the specific needs of poor farmers.

In contrast to participatory varietal selection (PVS), which provides farmers with improved varieties that already exist but have not been tested in their own fields, COB creates new variability by allowing farmers to use a few carefully chosen PVS cultivars as the parents of crosses. That means that we go to the farmers to understand their priorities, and their needs in terms of the stresses (soil moisture stress, low and erratic rainfall, poor soil fertility etc) that they face in the marginal environments in which they live. We work with the farmers to identify at least one of the parents which will be used in the crossing: for example, working together with the farmers, they may choose to cross a high-yielding but low-grain-quality variety with a variaty containing superior grain characteristics. Scientists then grow very large populations - perhaps starting with more than 10,000 plants in total - so that subsequently any trait governed by recessive genes will be expressed. It is then easier for farmers to pick out the varieties that they find most useful. For instance, farmers may look for a variety which gives a good return in moderate, even stressful conditions, but which will produce higher yields if they are able to increase crop inputs.

Whilst we have found that PVS may have its limitations, it is useful to use PVS in combination with client-oriented breeding. So we not only use PVS to identify the parents but as soon as there are products from this COB/PPB approach, they are tested in PVS trials. In this way, usually only one or two crosses are produced per year but this approach is more beneficial as it directly meets farmers' needs, is cost-effective, takes less than half the time of conventional breeding and allows these varieties to be directly placed into the hands of farmers, who can benefit most.

In the marginal areas of India, Nepal and Bangladesh there has been less than five per cent adoption of green revolution varieties. In less than ten years, however, with using PVS and COB, hundreds of trials have been conducted on farmers' fields and we have observed over 50 per cent yield gains in India, 20 per cent in Nepal and over 30 per cent in Bangladesh. Each year, the adoption of these farmer-selected varieties has been significant and is continuing to increase. By 2010, we are hoping that if present trends continue almost 30 per cent of shallow-water rainfed rice in Bangladesh will be planted to these varieties. In India, the rate of transfer has been less due to a number of factors, including drought, erratic yields and the small surplus of seed that is available for sowing with farmers after they have met their needs for food and grain sales.

In Bangladesh, particular success has been achieved with a rice variety originally bred in Nepal, known as Judi 852, which matures over three weeks earlier than Swarna, the most popular rice variety grown by farmers in High Barind Tract of Bangladesh. This early-maturing variety not only provides more time in the cropping season for farmers to grow a second crop but they also prefer its improved cooking and eating qualities. And, although Judi 852 was only introduced in the main season, we found that farmers also grew it in the winter (Boro) and spring (Aus) seasons. One farmer was so satisfied with the performance of this variety that he named it "Sundar Dhan", meaning beautiful rice.

Although we have only just commissioned an impact assessment on this variety, our initial findings have been very encouraging. Farmers in some villages have been able to sell surplus grain as well as seed and thereby generate valuable extra income. For instance, we have been given a figure of around £28 pounds per hectare in extra income, just due to the additional grain or seed that farmers could produce in one season. This means that if these varieties are grown over both seasons, and the rate of current spread continues, we are very hopeful that this variety, selected through our client-oriented approach, will bring considerable economic benefit to Bangladesh.

Date published: January 2006

 

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