February 2002

NEWS FROM THE DRY TROPICS:

1. 36 Percent -- and Rising!
2. Of Stalk and Livestock
3. Stalking the Enemy
4. Sorghum Scoop from Mali
5. Highlights of Previous Issues

1. 36 Pecent -- and Rising!

Tanzania produces more sorghum and millet than any other country in southern Africa. Although these ancient crops have been cultivated for millennia, cultivation methods have changed little.

Most farmers still use traditional landraces that give low yields and are often wiped out by drought. They can afford few inputs and rarely bother with new crop management methods. But things are changing, thanks to partnerships brokered by the ICRISAT-led Sorghum and Millet Improvement Program (SMIP). In the early 1990s, improved varieties occupied barely 5% of Tanzania’s sorghum andmillet area. Today that figure has risen to 36% for sorghum and 27% for pearl millet. (Left, evaluating the harvest).

Very rarely do adoption levels rise so much, or so quickly. The magic ingredient: partnerships. Specifically, SMIP efforts helped strengthen Tanzania’s breeding program by

• providing improved germplasm and breeding lines,
• sponsoring training programs for both research and extension staff,
• helping create farmer awareness of new technologies, and
• improving the production and delivery of seed by both the formal seed system and informal community-based initiatives.

Donors – USAID, GTZ and others – kept faith with researchers as they fought to develop technologies suited to a harsh environment with poor soils and unpredictable rainfall. Equally important, the network of partners was expanded to include NGOs and the private sector. These efforts are paying off handsomely.

In the 1980s, few improved varieties had been released in Tanzania. The most recent release was sorghum variety Tegemeo in 1986. Enter SMIP, and a stream of new products started flowing from the mid 1990s – notably sorghum varieties Pato and Macia, and pearl millet varieties Okoa and Shibe.

Despite plenty of anecdotal evidence of rapidly growing adoption, however, little hard data was to be found. A formal survey was therefore conducted to assess adoption levels. It covered the most important districts in the country. The data show that improved varieties currently occupy about 36% of Tanzania’s sorghum area and 27% of pearl millet area.

Higher adoption means higher productivity, higher incomes, and more food on the table for farm families. But many challenges remain. For example, why do adoption levels differ across the country, and what can be done about it? And how can we ensure that new technologies, and the extension staff to promote them, reach farmers in remote areas, where the problems are most severe?

For more information, contact g.heinrich@cgiar.org

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2. Of Stalk and Livestock

In the movie City of Angels, a man proposing to a woman says, “Lets get married – we’re the same species.”

While it is unthinkable that the parties involved in a marriage are not of the same species, there are no such restrictions for collaborations. The International Livestock Research Institute (ILRI) and ICRISAT do not have an obvious field of common interest. But ruminant livestock, which contribute to human welfare by providing food, draft power and manure, consume crop residue as fodder. This is the common ground for collaborative research.

A multidisciplinary research team of scientists funded by the Indian Council of Agricultural Research (ICAR), the UK’s Department for International Development (DFID), the Australian Center for International Agricultural Research (ACIAR) and ILRI, set out to identify genotypes of sorghum and pearl millet that could be used to develop plants with greater biomass and nutritive value without sacrificing grain yield. Though the funding for this project will end in 2002, the task is far from over, and efforts are on to obtain fresh funding from DFID and ACIAR, as well as from BMZ in Germany. A new joint proposal was recently invited by BMZ aimed at enhancing the livelihood of smallholder crop livestock farmers through improved dual purpose food feed crops and better natural resource use in areas of high rural poverty. (Right, farmer feeding the bullock with sorghum stover).

How do the scientists propose to investigate?  Plant Breeders generate thousands of entries every year to identify the best dual-purpose varieties. Animal nutritionists need to predict stover quality from these samples quickly and accurately through appropriate laboratory techniques. However, these techniques need to be validated through animal performance trials. Experiments with sheep devised by an ILRI scientist at ICRISAT-Patancheru meticulously measure all input and output of the animals. The ultimate aim is to identify stover that will promote a high level of animal performance and efficiently convert carbon and nitrogen into useful products such as milk and meat.

For more information contact b.reddy@cgiar.org, or c.t.hash@cgiar.org, or s.pande@cgiar.org, or m.blummel@cgiar.org

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3. Stalking the Enemy

Pursuing an enemy you can see is difficult enough, but when the enemy operates underground, catching hold of him becomes almost hopeless.

Peanut clump virus (PCV) is a nasty adversary of African peanut (groundnut) farmers. Pitting their wits against this wily disease, researchers use cutting-edge tools to track it down and destroy it.

PCV causes losses valued at over $40 million worldwide every year. Adding insult to injury, the disease uses various guises. In Africa it is known simply as PCV, while in Indian subcontinent the scourge is called Indian peanut clump virus (IPCV).

Although it prefers attacking groundnut, PCV infects a whole range of cereals and legumes, including maize, sugarcane, wheat, barley, sorghum, millet and cowpea.

The main symptoms of PCV attack on groundnut are severe stunting of infected plants, chlorotic lesions on younger leaves, and dark green older leaves.

Philippe Delfosse (left, in a groundnut field) is an ICRISAT virologist based in Niger. Delfosse, who has carried the fight to PCV since his days as a PhD scholar, says “PCV is soil-borne and is vectored by the fungus Polymyxa graminis. This parasite survives for many years in the soil in the form of highly resistant resting spores.”

Delfosse is closely involved with a special collaborative project between ICRISAT and the Université Catholique de Louvain in his native Belgium, with support from the Belgian government. The aim of the project is to better understand the complex epidemiology of the peanut clump disease in West Africa and to develop simple cultural practices to control it.

To do this, the project scientists first tried to determine the biodiversity of PCV and Polymyxa isolates using diagnostic tools. They found that in groundnut PCV is transmitted through seeds. “To prevent further spread of PCV in West Africa, extreme caution is essential in selecting the seed,” Dr Delfosse commented.

Because no resistance to PCV has yet been identified in cultivated groundnut, scientists are evaluating wild Arachis species for sources of resistance to the virus. Meanwhile, the most feasible method of managing the disease currently available is through such cultural practices as trap cropping with millet and judicious time of sowing. These methods have significantly reduced clump disease incidence in India.  

Future plans for the project include:

·         Production of diagnostic tools for detecting PCV

·         Development of effective cultural practices

·         Development of a prediction model

·         Training

·         Publication of an information bulletin

For more information contact p.delfosse@cgiar.org