Tropical and Subtropical Fruits and Vegetables

Tropical and subtropical fruit and starchy root and tuber crops are among the most important components of diets in many parts of the world (Tables 1 and 2). They are also important sources of hard currency income, either from the export of fresh or processed food or from the sale of secondary products. Recent trends in the growth of tropical fruit production suggest that consumers in many temperate countries are discovering tropical fruit (Table 2). There is currently a massive expansion of the tropical fruit industry in Central America, South America and in many Caribbean countries. Most tropical fruit, root and tuber crops have been vegetatively propagated for several hundred, and in some cases, for several thousand years. Clonal propagation methods that have been used have ranged from relatively sophisticated grafting techniques with some fruit cultivars (12) to direct planting of tuber or stem pieces with some of the starchy root and tuber plants. In this way, the unique genetic balance of plant selections has been maintained. With the passage of time, however, many of these clones have become highly vulnerable to increased disease pressure. Classic examples of this phenomenon during the twentieth century have been the devastation of ‘Gros Michel’ banana production in Central America by Panama disease and the more recent epidemic of black Sigatoka disease among cooking bananas (plantains) in the same region. Finally, the spread of acquired systemic viral and bacterial infections has been facilitated by clonal propagation methods. These diseases have become the most important factors that limit production of Citrus, yam, sweet potato, cassava, and various edible aroids.