In addition to be used as a trap plant in the Push-Pull technology, Napier grass is the most important fodder crop in smallholder dairy production systems in East Africa, characterized by small zero grazing units. The major threat to adoption and expansion of the push-pull technology, and to the smallholder dairy industry, is the stunt disease of Napier grass . The etiology of the disease is known to be a phytoplasma, 16SrXI strain. Although, the putative insect vector was yet unknown, we have recently identified a leafhopper, Recilia banda Kramer (Hemiptera: Cicadellidae) as the vector of Napier stunt phytoplasma in Kenya,

Climate change is anticipated to have far reaching effects on sustainable development of sub-Saharan Africa (SSA), including the ability to attain the Millennium Development Goals (sdgs). Rainfall is becoming progressively more unpredictable in the region, accompanied by increases in atmospheric temperature. Predictions indicate that these trends will continue, together with increased incidences of floods and drought, expanded host and habitat ranges of pests and weeds (and pressure from these). Moreover, Agriculture is expected to intensify during the next few decades to meet the extra food demand from a growing population. These will result into progressively more serious land degradation, increased incidences of crop failure and general increases in food and nutritional insecurity among resource poor farmers in the region.

The shortage of desmodium seeds is an important limiting factor for much wider dissemination of the 'Push-Pull' technology in sub-Saharan Africa (SSA). Although technology and methods for the production of seeds and development of local markets are now developed in collaboration with farmers, local seed companies and stockists, availability of large quantities of good quality seeds is essential for the planned full scale expansion. Recently an external review of icipe programmes concluded that this problem should be given high priority as it is a major cause of the limited spread of the 'Push-Pull' system. According to the reviewer efforts to select high seed yielding varieties should also be undertaken.

Due to high demand of the 'Push-Pull' technology and unavailability of desmodium seed in market, two informal pathways have emerged during last three years:

1) Vegetative propagation among small holder farmers.

2) Community-based seed production initiatives.

Although, vegetative mechanism could evolve into an important mechanism for local diffusion of the 'Push-Pull' technologies among resource-limited farming communities, large quantities of seed is still required, through both formal and informal systems, for massive expansion of the technology in SSA. We are presently analysing and comparing the relative merits of formal and informal pathways in stimulating autonomous diffusion of the Push-Pull technology.