Napier grass is the main fodder for the smallholder dairy industry in eastern Africa, and is also being used by more than 30,000 farmers in the region as a trap plant in the push–pull technology for management of cereal stemborers. Recently, a new stunting disease of Napier grass has emerged in the region, decreasing Napier grass yield by 70%, and causing significant decline in milk output. There is also a potential risk that the disease might spread to food crops, e.g. sugarcane, rice, millet, sorghum etc., causing a serious threat to food security in the region. The disease, caused by a 16Sr XI phytoplasma strain, is spreading fast in the region, with potential to escalate to other areas in sub-Saharan Africa with similar agroecologies. icipe scientists have recently identified the leafhopper Maiestas (Recilia) banda Kramer as the vector transmitting the disease in western Kenya and have optimised phytoplasma diagnostic procedures such as polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP).

This project seeks to identify Napier grass varieties resistant to the phytoplasma and elucidate both the mechanism and durability of the resistance; expand the fodder resource base by identifying alternative fodder grasses; identify and develop management approaches for the alternative hosts of phytoplasma and vector; identify, train and engage farmers in community-based planting material production and distribution in the target areas; integrate with field hygiene and implement in the target areas; evaluate the potential risk of the disease spreading to cultivated grasses, and develop early warning signs; and form strategic alliances for wider dissemination of the approach and allow cross-learning. Deployment of the approaches will address the production losses resulting from effects of the Napier stunt disease, and improve dairy and cereal productivity in the region.

Objectives:

1. To screen and identify Napier grass varieties resistant to the Napier stunt phytoplasma and to elucidate mechanisms and durability of the resistance;
2. To participatorily identify alternative fodder grasses that are resistant to Napier stunt phytoplasma in the target areas;
3. To establish efficient community based multiplication and distribution systems for resistant Napier grass planting materials to improve farmers’ access to them while serving as a source of income to the communities;
4. To identify alternative hosts for both vector and Napier stunt phytoplasma and develop management approaches for them to curb spread of the disease;
5. To assess threats of the stunt disease to food crops and develop early warning signs and response systems;
6. To develop and implement an integrated management approach for the Napier stunt disease in East Africa and build capacity of stakeholders in the dairy value chain in the target areas on disease diagnosis, management and animal husbandry.