To foster the adoption of sustainable intensification practices amongst Ghana's farmers, they are widely promoted through training sessions provided by development organizations, companies, and the public extension service. We investigate whether these training sessions are effective and find that they are effective only for the diffusion of organic fertilizers but not for mulching. We suggest that this comes from the complexity of the innovations. Mulching is one of the simplest sustainable intensification technologies. It diffuses easily through peer learning and, after an initial training delivered to a critical mass of farmers, does not require training anymore. The use of organic fertilizers, in contrast, requires more specific knowledge and adaptation, which limits the effectiveness of peer learning and increases the effectiveness of training. This suggests that to achieve a widespread diffusion of sustainable intensification amongst Ghana's farmers, training sessions should focus on those practices that are complex and thus difficult to learn from peers.

Indiana growers who purchase restricted-use pesticides are required to show the agrochemical dealer their private pesticide applicator license before the transaction can be completed. To keep the license current, growers may attend three private applicator recertification meetings or retake the exam every 5 yr. The meetings are county-based and must be a minimum of 2 h in length; they must include a topic mandated by the Office of the State Chemist. During the 2005/2006 private applicator recertification program (PARP) cycle, off-site movement of atrazine into surface water was the regulatory topic presented to 2,887 participants at 69 meetings. A team of individuals from different disciplines prepared educational materials to support the regulatory topic of the year. Surveys to assess grower awareness were conducted at the meetings and 1 yr later to monitor the long-term impact of the educational effort, and to evaluate which tactics were being adopted to reduce off-site movement of atrazine. Growers farming more than 800 ha had a higher degree of concern than small growers regarding the loss of atrazine as a weed management tool. Eighty-nine percent of the growers thought there would be a 314 to 1,255 kg/ha yield loss if atrazine was removed from the marketplace. Eighty-four percent of the growers estimated that weed control costs would increase $15 to $25/ha if no other products were available to replace atrazine. The three most acceptable management strategies to reduce atrazine movement were: more attention to label setback distances, establishment of grass filter strips around surface water, and reducing atrazine rates by tank mixing with other herbicides. The results of this project indicated that statewide programs such as this are effective in increasing awareness of an issue and documenting the impact of extension education programs.

Industrialization is rapidly becoming a topic of great attention. Driven by fundamental economic forces, industrialization seems likely to advance more quickly in the coming decade to more industry segments. By changing the way agriculture does business, industrialization will also bring change to public policy and agricultural institutions. Commodity policy will increasingly be out of step with a product-oriented industry. And as industrialization blurs the lines between producers and processors, land grant universities and the extension service will face challenges assessing who their customers are.

An initial study of the extension service and pest control in Iganga district was made between 14 July and 20 August 1987. This was part of a more extensive on-farm study of pest control problems in the district. This study covered 36 small scale farmers randomly picked from the three agricultural sub-zones in the district.

It was observed that: (i) information on crop protection was scanty, (ii) the majority of the farmers were aware of the presence of pests on their farms, (iii) there is a minimal use of pesticides on small scale farms in the district, (iv) a number of pests occur in varying frequencies on small scale farms in the district and (v) the extension staff are still too few to handle even the general aspects of crop production.

Farmers and the agricultural research and extension community at the land grant universities have experienced an evolving relationship. The current call for reform in publicly sponsored agricultural research and extension is built upon more than a century of dialog. If specialization and discipline-oriented research is to continue, the ecosystem-based knowledge of the farmer will become increasingly valuable. Involving farmers more actively in research and education could be achieved in several ways. Outside the land grant system, nonprofit agricultural research and demonstration organizations are being developed. Within the public system we need a renewed emphasis on extension at the local level and a revitalized applied research effort aimed at solving problems of the agricultural ecosystem rather than single disciplines. A dynamic and resourceful agriculture could result from including the farmer as a full partner in land grant research and education.