A few months ago I "attended" the UN Food and Agriculture Organization's email conference "Learning from the Past: Successes and failures with agricultural biotechnologies in developing countries over the last 20 years." I really enjoyed hearing the opinions of dozens of working scientists and regulators from the developing world (and a few based in the developed world) regarding the best uses of biotechnology in their countries.
They haven't posted their promised summary yet, but I seem to recall three major themes:
1) Many plant pathogens (particularly viruses) are unable to infect plant seeds, allowing plants to produce healthy offspring even when they are sick. Unfortunately, many important tropical crops (e.g. plantain, potato and cassava) can only be reproduced by cuttings (not by seed) - leading to chronic crop infections in many developing countries. A distributed network of small laboratories could play an essential role providing clean, disease-free cuttings at low cost or free to smallholder farmers and could also supply locally-appropriate agronomic advice and a link to national/regional universities and the greater scientific world beyond.
2) Simple, locally-appropriate technologies (such as fermentation of certain crops) can improve the nutritional quality and shelf life of available resources. There are lots of great scientists documenting (and improving) these techniques but implementation has been limited by a lack of extension workers.
3) Genetic engineering holds great promise to add valuable traits to locally-adapted crops (e.g. eggplant) - but has been stymied by very well-funded environmental special interest groups from the United States and Europe. This is all the more ironic/tragic as many of these new crops are being developed by public sector scientists for their smallholder countrymen. No less ironic is the role these "liberal" special interest groups are playing denying self-determination to their former colonies.