Progress 09/15/06 to 09/14/08
Outputs
OUTPUTS: This project evaluated varieties developed by the University of Hawaii under the same conditions of those of the Caribbean Basin in an effort to lessen the negative consequences taro leaf blight represents to Puerto Rican farmers. Selected county agents attended a seminar and field trip activity designed to improve their knowledge on field identification of disease symptoms. Information was given as to the taro origins, crop movement, new uses, and current status of genetic improvement. This audience was capable of identifying the symptoms in the field and gained knowledge regarding the devastating economic consequences of the blight. Resistant varieties offer the best long-term control of taro leaf blight. Ten improved varieties were imported from Hawaii into Puerto Rico and evaluated for horticultural traits and tolerance to the disease. Although classified as blight-tolerant under Hawaiian conditions, nine of the varieties resulted more susceptible to the disease than the local varieties. Incidence of taro leaf blight tends to be less under the upland production system. More than 75 participants, among whom were 50 farmers and 13 county agents, visited our facilities for a field day. We established a two-acre plot under upland conditions with drip irrigation to provide information in regard to the phytosanitary condition of the crop, plant development, yield, corm quality and quality of propagation material. This activity, an integrated effort for research and education, was conducted interactively; thus, farmers examined the crop in the field. The evaluation of the field day showed a high degree of satisfaction for the work done under this project. The significant output of this field day was posted on the Experiment Station Web Site. By also utilizing newspaper coverage this project reached the general public. Two reports were made. The first, in 2007, was published in the newspaper El Oriental. This article, written in Spanish, pointed out the activities that occurred during the field day as well as the research strategies to lessen the effects of the disease. The second article, published in 2008 in the newspaper Primera Hora, further pointed out the combined research efforts of the Universities of Puerto Rico and Hawaii. Both publications reached additional stakeholders and articulated the results in a way understandable to the general public. Taro production in Puerto Rico was concentrated in the municipalities of Yabucoa and San Lorenzo. The Commission of Agriculture of the House of Representatives carried out a legislative study on the socioeconomic consequences of the disease among farmers of these municipalities. We provided the officials of the Puerto Rico Department of Agriculture information regarding activities within this project. Among the findings of the above mentioned study was the fact that introducing and evaluating improved varieties from the Pacific Basin was a reasonable and practical strategy to deal with the situation. As part of the outreach strategies a limited amount of planting material was given to producers interested in establishing observation plots on their farms. PARTICIPANTS: Carlos E. Ortiz, Professor of Plant Breeding, University of Puerto Rico. Evaluated varieties from Hawaii for horticultural traits and for tolerance to the leaf blight. John J. Cho, Professor of Plant Pathology, University of Hawaii. Bred taro varieties imported into Puerto Rico. Evaluated varieties for tolerance to the blight. Evelyn Rosa Marquez, Associate professor of Plant Pathology, University of Puerto Rico. Evaluated varieties for tolerance to the blight under field conditions. Luis E. Rivera, Researcher of Agronomy, University of Puerto Rico. Selected adequate irrigation strategies for taro under upland conditions. Edwin Abreu: Professor of Entomology, University of Puerto Rico. Confirmed aphids as a nuisance for taro production under upland conditions in Puerto Rico. Gregorio Rivera. Deputy Director for the Land Authority of Puerto Rico; a division of the State Department of Agriculture. Coordinated activities between the project and the Land Authority for the establishment a pilot project for upland taro production in the Coloso Valley in Western Puerto Rico. Manuel Diaz Rivera: Extension Starchy Crop Specialist and Professor of Horticulture, University of Puerto Rico. Coordinated project activities with county agents and organized the field day conducted under this project. TARGET AUDIENCES: Farmers: A major need for this audience was blight-tolerant varieties of taro adaptable to the Puerto Rican system of field management and market, as well as the need for information to make management decisions for production under upland systems. County Extension Agents: Over 15 extension agents participated in the project activities improving their knowledge regarding field identification of the disease symptoms and regarding production loss as a consequence of this disease. Government professional (State Department of Agriculture): High prices for taro corms increased their interest in promoting the production of taro under upland conditions. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
This research documents that the traditional varieties of taro used in Puerto Rico; Lila and Blanca, highly regarded for their table quality, were very susceptible to the taro leaf blight; thus, alternative varieties should be found if production of this specialty is to be maintained. This research further documents that taro varieties from Hawaii can be grown successfully under Caribbean Basin conditions. Access to such varieties is important because they have genes of tolerance to the blight. However, eating qualities or the latter varieties might be different from those accepted in the Caribbean. The relatively low production of taro within the Caribbean Basin as a consequence of the leaf blight has increased the price for taro corms. High prices have promoted interest in taro farming under upland conditions as well as interest in the new blight-tolerant varieties from Hawaii. Incidence of leaf blight tends to be lower under the upland production system. This situation led farmers to participate in a field demonstration conducted under this project. More than 75 participants, among them 50 farmers, and 13 county agents, visited our research facilities for a field day, thus increasing their knowledge in regard to the phytosanitary condition of the crop under upland conditions, plant development, yield, corm quality and quality of propagation material. The evaluation for the field day showed a high degree of satisfaction for the work done. This research documented the minimum amount of irrigation needed to produce taro. Under upland conditions and under the presence of the blight, water to be applied by irrigation should replace at least that lost through evapotranspiration. Corms obtained when grown under the above system had similar eating attributes- -taste, texture and acridity- - as those corms grown under wetland conditions. Stakeholders pointed out that the lack of planting material is an important factor that limited the upland production. More than 3,000 setts were sold to farmers who visited the station. Those numbers do not include setts given to farmers to establish observation plots. These observation plots also served for planting material increase. The Puerto Rico Department of Agriculture showed interest in promoting the production of taro under upland conditions in the Coloso Valley. This land was in sugarcane and now is in transition to root, tuber and vegetable production. Practical information was given as to growth, yield, corm quality and the minimum irrigation requirement for upland taro production. This project provided the initial 2,000 setts for seed increase in the Coloso Valley. Research results further document that under upland conditions the fungus Cladosporium tenuissimum caused reddish-brown leaf spots affecting the effective leaf area. Cucumber mosaic virus and Dasheen mosaic virus were found affecting some varieties under evaluation. Aphis gossipy appears as the possible vector for such viruses.
Publications
- Ortiz C.E., J.J. Cho, E. Rosa-Marquez and L.E. Rivera, 2007. El tizon foliar de Colocasia esculenta en Puerto Rico. Proceedings of the Caribbean Food Crop Society 43:134-138.
- Rivera, L.E., C.E. Ortiz, and J.J. Cho, 2008. Response of Taro var. Lila or Bun Long to Levels of Supplemental Irrigation. Proceedings of the Caribbean Food Crop Society 44: In Press.
- Rosa-Marquez, E. and C.E. Ortiz, 2008. First Report of Cladosporium tenuissimum Cooke on taro in Puerto Rico. Proceedings of the Caribbean Food Crop Society 44: In Press
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