Towards Sustainable Yam Production in Puerto Rico

Yams (Dioscorea spp.) are considered a staple food in tropical and subtropical regions. They provide a rich source of vitamin C, potassium, manganese, and fiber and are low in cholesterol. In Puerto Rico, yam is the most economically important tuber crop, and the most cultivated yams species include Dioscorea alata and Dioscorea rotundata. After Hurricane María, the potential of this crop in Island food security became evident as it was one of the crops that survived this natural disaster by being planted underground. Even though yam's importance to food security is quite evident, constraints in seed supply limit its sustainable production in Puerto Rico. Yams are conventionally propagated by tuber seeds; even though this system is functional, it presents a sort of difficulties such as a build-up of diseases and a source of contamination that often become the opening for spreading pests and diseases. Currently, farmers face difficulty accessing enough disease-free propagation material and keeping high-quality material under storage conditions while dormancy is broken. Internal dry rot, dry rot, and anthracnose are the most limiting diseases to the local yam production in Puerto Rico. Due to these yam production problems, our research focuses on providing disease-free seed of D. rotundata using tissue culture techniques, minisetts propagation techniques, early detection of plant pathogens, and the evaluation of effective management strategies for disease control to improve seed quality. Employing the minisetts technique utilizing pre-sprouted seed of 20, 35, and 50 g at three planting distances (0.05, 0.10, and 0.15 m), we obtained high-quality tubers of 220-260 g. Using the Temporary Immersion Bioreactor system (TIBs), we demonstrated the capacity of these techniques to increase multiplication rates and rapidly propagate disease-free plants. Harvest tubers from this technique increased crop uniformity and reduced losses caused by plant pathogens on exposed cut tissue at planting. Field trials to evaluate potential fungicide to manage anthracnose disease identified a combination of Cyprodinil and Fludioxonil as the most effective ingredients reducing the levels of disease. Also, as part of efforts for the sustainable production of yams on the island, we developed a training program for local farmers to train farmers in disease management practices and disease-free seed production. Our ultimate goal is to achieve food security through increased local production of yam that guarantees sustainable crop yields and affordable food while also increasing sources of income for our local farmers.