General information

Napier grass smut and stunt resistance project

Napier grass was named after colonel Napier of Bulawayo in Zimbabwe who early in the last century urged Rhodesia’s (now Zimbabwe) Department of Agriculture to explore the possibility of using it for commercial livestock production.

Napier grass is a major livestock feed. Fresh grass contain 77.8g water, 1.0g  protein, 0.5g fat, 17.6g total carbohydrate, 3.1g ash, 0.12% calcium and 0.07% phosphorus (Duke, 1983). It can yield 50-100 tonnes green matter per hectare if recommended agronomic practices are implemented. Other uses of Napier grass include management of stem bores as a trap crop (Push-Pull strategy), conservation of natural enemies of other potential crop pests and prevention of soil erosion. Napier grass and milk can be sold as a source of income. 

Two major diseases; Napier stunt, caused by tiny bacteria (phytoplasma), and smut, caused by fungi, can cause serious reduction in yields if not managed. Most varieties are susceptible to stunt and smut. Decline in biomass due to either smut, stunt or both will lead to loss of farmers' income from the sale of milk because shortage of livestock feeds due to disease and, high costs of managing the disease will double prices of Napier. Farmers will be forced to sell their dairy cows or graze them on sparse communal pastures along the road side, thus exposing them to the risk of contracting East Coast fever which in turn increase the costs if livestock production because farmers will have to treat their livestock. 

Importance of smallholder dairying in Kenya

  • Kenya has the largest dairy sub-sector in eastern Africa making available annually an estimated 85-90 litres of liquid milk equivalent per capita based primarily upon well-established market-oriented smallholder dairy systems.
  • Many smallholder farmers in East Africa depend on dairying for their livelihoods, both cattle keepers and feed growers. In a survey in Central Kenya, it was found that 73% of agricultural households have dairy cattle (Staal et al., 2001) and in most districts, these households ranked dairy as the most important source of income (75% in Nairobi district). In Kenya, resource poor smallholder dairy farmers produce more than 80% of the marketed milk (Peeler and Omore, 1997).
  • Napier grass (Pennisetum purpureum) is the most important forage crop in cut-and-carry zero grazing systems in the Central Kenya Highlands (Staal et al., 1997) and has been shown to constitute between 40 to 80% of the forage for the smallholder dairy farms. In Kenya alone, about half a million smallholder dairy producers rely on Napier grass as a major source of feed
Napier in Tanzania

The majority of farmers in rural areas practice crop/livestock farming. Livestock production is constrained by land shortage, droughts, and pests and diseases. Farmers experience shortage of fodder during dry seasons and they get fodder from the established plots near homesteads. Few buy from pasture farms while others travel long distances to collect forage grass. Common fodder grasses include Napier, Guatemala, Setaria and leguminous trees such as Leucaenae. Napier is the most common fodder grass in the Northern, Lake and Eastern zones.

Land degradation is a major environment concern to sustainable agriculture production. Contour bands are promoted to reduce run-off and conserve moisture. Napier, Guatemala or leguminous trees are planted to stabilise the bands. The fodder is used as livestock feed. These is practised along the mountain sloped e.g. Pare, Usambara and Mufindi.

Importance of smallholder dairy farming in Uganda
Dairy production is a source of milk and income in Uganda. Napier grass (Pennisetum purpureum) constitute 40 to 80% of the forages for the smallholder dairy farms. Napier head smut, a fungal disease caused by Ustilago kamerunesis, and Napier stunt disese (NSD) caused by phytoplasma are reducing Napier yield in East Africa.

Reducing the disease impact
  • Planting material: The main source of infection of both diseases is believed to be through distribution of infected planting material. Ensuring that only clean material is distributed will help prevent the spread of the disease. This can only be done by testing the planting material for infection before bulking. 
  • Management strategies: Managing Napier plots to maintain strong healthy plants and to eliminate the infection pool will mitigate the effects of the diseases. Farmers need to:
-Inspect crop regularly and remove diseased plant
      -Keep Napier healthy by weeding and manuring plots
  • Disease resistance: A longer term control strategy is to identify Napier grass clones that are resistant to the diseases, such as the ones for smut: Kakemega I and II. However, while these are smut resistant they are not as productive as the best local varieties. So high yielding resistant clones are crucial to meet farmers’ needs.
Generating and sharing knowledge: The key to the project is generating and sharing knowledge to ensure that farmers know about the disease, share how best to manage it, know about disease resistant clones when they have been identified and how to get them.
In this way the project will help farmers avoid the worst effects of Napier grass smut and stunt, diseases that are posing a real threat to the livelihoods of smallholder farmers in the region.

Further reading
  • Kenya Agricultural Research Institute, KARI, 2008. Research and Management of Napier Stunting and Smut disease Project Kenya. Kakamega, Kenya: KARI.
  • Napier Stunt and Smut Diseases in Uganda. (413KB pdf)
  • Pallangyo, B., 2005. Diseases of Napier, Pennisetum purpureum (Shumach) Poaceae in Tanzania. Tanzania: National Biological Control Programme.
Jean Hanson,
16 Jul 2010, 07:26