While the principle that light reduces potato sprout growth has been long established in scientific literature, the International Potato Center in Peru (CIP) has adapted the technology for use by potato farmers in developing countries. The results of DLS have had wide reaching effects within developing countries that depend on potatoes as a primary staple crop.
CIP tested demonstration models of DLS structures in the community of Benguet in the Philippines. Since its introduction in 1978, DLS has been rapidly adopted. Through the CIP project in the Benguet Province, demonstration units (for storage of 1-5 tons of seed potatoes) were built with timber or bamboo poles with shelves made of thin bamboo strips. They used local thatch for the roof and a combination of corrugated plastic sheets and fly screen for the walls. Basic criteria for a DLS structure is that it have an insulated roof translucent walls, and adequate ventilation. The adoption of the DLS in some other developing countries including Guatemala and Sri Lanka, is remarkably similar. Farmers tend not to build new stores or copy demonstration stores precisely, but rather to modify existing dwellings to meet their needs and budgets.
The transfer of DLS resolved several of Sri Lanka's problems with potato production. DLS cut storage losses and increased yields, thus reducing the need to import expensive potato seed. Since farmers produced their own potato seed they were not dependent on shipping dates of imported seed, and could plant during optimal conditions. Planting at optimal times resulted in more spaced harvests and provided farmers with extra time to cultivate another crop. As more farmers adopted DLS, Sri Lanka reduced its dependency on foreign seed imports, and brought prestige to their agricultural research and extension programs.
In the Philippines, one case study compared potato seed stored in diffuse light storage to seed stored under traditional methods. Potatoes stored in diffuse light showed a twelve percent increase over the traditionally stored seed.
A survey was conducted in Philippines to determine the amount of adoption of DLS technology. The Philippino farmers stressed the marked differences of the shorter and sturdier sprouts, and the subsequent vigor of plants whose seed had been stored in diffuse light. They noted that short sprouted seed from DLS was easier to handle during transportation and planting. Respondents indicated that the emergence of DLS seeds was faster and more uniform than traditionally stored seeds. Ninety-five percent of farmers interviewed who used DLS found that the plants produced from these stores were of better quality and gave higher yields than those from traditional stores. The other five percent indicated no beneficial yield effects of DLS.
While DLS seems to have been adopted by a large number of farmers, thirty-five percent of the farmers interviewed were still not aware of the technology. These potato growers were from remote areas. DLS may not be an option for farmers who are very isolated or who can not afford to sell their seed or to buy translucent siding. Work needs to be done to address the issue of outreach and resource availability to isolated farmers.
Michael Potts. 1983. Diffuse Light Potato Seed Storage as an Example of Technology Transfer: A Case Study. American Potato Journal 60 217-226.
Richarte F Acasio, Amado de los Santos, and Peter Vander Zaag. 1986. Acceptance of Diffused Light Storage Technology by Potato Farmers in the Benguet and Mountain Provinces of the Philippines. American Potato Journal 63 162-170.