Training of Growers and Extension Agents in the Dominican Republic

The Dominican Republic is situated on the Hispaniola Island in the Caribbean region.  Its climate shows considerable variation over short distances and is the most diverse of the Caribbean. Annual average temperature is 25 °C, ranging from 18 °C (at higher elevations) to 28 °C (at sea level). Average annual rainfall is 1500 mm. Although sugar, coffee, cocoa, and tobacco are the principal cash crops of the country, the Dominican Republic shows an increasing production of citrus and tropical fruit (banana, pineapple, guava, tamarind, passion fruit, soursop, coconut), spices, nuts, and vegetables (tomatoes, carrots, lettuce, cabbage, coriander, scallions, onions, and garlic). Regarding the latter, diverse peppers are also gaining increasing importance on the country’s exportation market. Usually, they are grown in tunnels and greenhouses, where producers are challenged by high temperatures that result in reduced fruit yield and quality. In this presentation, the experience of training pepper growers and their extension personnel in the communities of San José de Ocoa, La Horma del Rifle, Las Auyamas, and Constanza will be shared. The objective was to train them on how to manage heat stress of bell pepper and other vegetable crops grown inside high tunnels and greenhouses. It was observed that bell pepper plants inside high tunnels showed symptoms of heat stress, including reduced plant and fruit size, small fruit number, and a mild leaf chlorosis. Growers were recommended to utilize shading nets (30% to 40% shade) placed on top of the high tunnel or greenhouse to reduce the incidence of solar radiation. Also, under warm conditions, they were advised to use white or silver plastic mulch (rather than black mulch) in order to reduce soil over-heating. To reduce air temperature inside high tunnels and greenhouses through the use of side vents and zenithal openings was suggested as well.