“My motivation to seek an M.Sc. study program came from my hope to grow professionally and work academically in developing countries – especially Ecuador- , where I can help people to improve their livelihood”, explains Israel Navarrete, who obtained the grant. Navarrete, who works at CIP as a research assistant on a project focused on potato seed degeneration, completed his first bachelor’s degree in Agronomy thanks to the support of the McKnight Foundation, which funded his thesis, entitled “Determination of potato losses in yield caused by tuber-borne diseases”.
Degeneration of seed (more appropriately called planting material) is a major constraint in crops that are vegetatively propagated, such as potato. In simple terms, degeneration is the accumulation of pathogens on tubers producing yield reduction across time. Among all the pathogens that affect the potato crop, viruses are considered the most important cause of seed degeneration. However, in the Andes, soil-borne pathogens seem to be just as important as viruses.
The current paradigm proposes to control seed degeneration by buying seed from formal seed systems, but this has proved to be impractical in most developing countries: certified seed can be expensive and is not always accessible at the time and in the amount needed. Farmers typically prefer to use their own seed.
The new paradigm that CIP and partners are proposing is to manage seed degeneration by breeding and disseminating cultivars resistant to the pathogens that cause degeneration, and improving the capacities of farmers to manage their own seed. Resistance seems to be the most sustainable way for managing seed degeneration, but it takes time. On the other hand, improving the capacities of farmers to manage their own seed can be readily applied with simple techniques, such as positive selection, negative selection (roguing), integrated pest management and improved seed storage. In the new paradigm, it is assumed that farmers may also purchase seed periodically for a number of reasons, for example, to acquire a new variety.
Navarrete’s thesis will contribute to quantifying and understanding potato seed degeneration under Ecuadorian highland conditions; and add data to develop quantitative models and decision-support systems to improve on-farm seed management.