All 'white' for Babati pigeonpea
Juma Ishmael stands in the middle of his farm dwarfed by a forest of pigeonpea bushes. His brown cap and shining face are a clear indication of the pride he possesses as he waits to harvest his crop. This year, the rains have been good, and the entire crop has grown to full maturity bringing Ishmael his biggest harvest for many years. And, not only for him, many other pigeonpea farmers in Babati district, Northern Tanzania have also harvested record yields.
Babati, in the Arusha region of Tanzania, is the country's most important pigeonpea area. The farming system is diverse with farmers growing sorghum, pearl millet and maize, along with a variety of legumes (pigeonpea, groundnut, cowpea, beans) and a few cash crops, including sunflower and simsim (sesame). But Ishmael remembers all too well the numerous crop losses he endured since he started growing pigeonpea several decades ago. For every season he planted, a significant proportion of his crop would be lost to fusarium wilt (Fusarium udum).
A fungal plague
Fusarium wilt, a soil-borne fungal pathogen, occurs when fungal infection develops within the water channels in the plant, constricting water uptake causing wilting and drying up of the crop. F. udum is the most serious disease of pigeonpea in Eastern and Southern Africa, causing losses of more than US$ 5 million a year in Kenya, Tanzania and Malawi alone. As the pathogen lives in the soil, it is difficult to control and is also easily spread to new plants through contaminated farm tools, water, wind, and by movement of animals and humans carrying fungal spores. Use of cultivars resistant to the disease is the only effective means of control.
Helplessly disillusioned, many farmers in Babati had abandoned their pigeonpea crops and turned to other alternatives as the disease took its toll. Over the ridge to Karatu area, farmers had to deal with an additional challenge. Not only was the disease affecting their harvest, but the seeds produced were discolored, and only fetching half the price normally expected for pigeonpea in the market.
A conventional but convincing approach
However, through participative research, farmers in these two areas are beginning to reap benefits. When researchers from the Selian Agricultural Research Institute (SARI) realised the problems farmers in Babati and Karatu were facing, they sought collaboration from the International Crops Research Institute for the Semi Arid Tropics (ICRISAT) to tackle the problem. Just a year ago, Ishmael's farm was the subject of admiration by other local farmers. He was among the first farmers to plant new varieties of the pigeonpea developed with resistance to Fusarium wilt.
According to Dr Said Silim, the ICRISAT director for eastern and southern Africa, the solution to the farmer's plight lay in conventional breeding. Field research was carried out in Tanzania and neighbouring Kenya, in areas with similar climatic conditions. It involved infecting the trial land with the fusarium wilt, and then planting several lines of the crop from genebanks in the region as well as from elsewhere.
For nine years, researchers from the two institutions worked on crossing land races and improved varieties to produce several varieties with proved desirable characteristics. After releasing the varieties for testing by farmers in Babati and Karatu, most farmers opted for three lines. The lines 40, 53 and 54 were resistant to the disease, while Line 40 produced no discolouring when planted at Karatu. Dr Silim explained that as Karatu is a high altitude area, most pigeonpea varieties were susceptible to the low temperatures, but line 40 proved tolerant to the climatic conditions.
With the new varieties, the farmers have been able to intercrop maize for household consumption. The varieties have also been returning a good harvest. From his nine acres, Ishmael used to harvest only three 90-kilo sacks, but now his yields have more than doubled. More than 35% of farmers in the Babati region are now growing improved varieties.
However, according to Dr Philemon Mushi, a socio-economist at SARI, despite improved harvests thousands of small-scale farmers (farming an average of 3-4 hectares) still face the problem of exploitative middlemen. "Whereas the international market buys pigeonpea per kilogramme, not so the brokers," he says. "They insist on buying the crop per sack usually at around Tanzania Shillings 30-40,000 (about US$ 35 a sack)."
To empower farmers, SARI researchers are working closely with the Catholic Relief Services to help bring farmers together in cooperatives. Together with another NGO, Technoserve, they have successfully worked with a number of farmers in improving standards to meet European requirements for exports of "Babati White".
Written by: Kimani Chege
Date published: January 2007
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