fvsu-003• Guava

Guava is native to the warm regions of the Americas stretching from Mexico to Peru. Although the guava plant was domesticated more than 2,000 years ago, it was not until 1526 when the first commercial cultivation of guava was reported in the Caribbean islands. Later it was spread by explorers into the Philippines and India. From there it quickly spread to most of the tropical and subtropical regions of the world where it has become naturalized to the point that in certain areas it is considered a noxious weed.

Ripe guava fruit is an excellent source of ascorbic acid (vitamin C) and dietary fiber. Guava is also a good source of vitamin A, phosphorus, calcium and iron as well as thiamine and niacin. Reportedly, consumption of guava fruit reduces serum cholesterol levels, triglycerides and hypertension while increasing the level of good cholesterol (high density lipoprotein). Both ripe and green fruits, the root, leaves and bark are used throughout the guava growing region in local medicine for treating gastroenteritis, diarrhea and dysentery.

Guava can be eaten as fresh fruit when ripe, prepared into sauce and chutney, or cooked as a vegetable when green. It can be processed for jam, jelly, nectar and fruit juices as well as flavoring for other foods. There are processing and fresh fruit or dessert varieties of guava with white, salmon red, or pink flesh and light green to yellow skin colors. The average diameter of fruit varies from 4 to 10 cm (1.6 to 4.0 inches) and weight may range from 150 to 400 g (5 to 14 oz).

Production

Guava is a tree fruit that is well adapted to human manipulation and to changes in orchard management systems. It responds well to controls in many stages of growth and development. Guava trees generally grow in a symmetrical dome shape and form shrubs or small trees which attain a height of 3 to 6 m (8 to 20 feet). Guava appears to be a very versatile tree which can adapt itself to many climatic and soil conditions. Apparently, soil type really does not appear to matter much when other growth conditions are not at limiting levels. Although the guava plant is tolerant of poor soil conditions, fruit production is enhanced when it is grown in rich soil with proper care and management. The guava tree is fairly salt and drought tolerant and can produce well in a pH range from 4.5 to 8.2. It thrives from sea level to 3,000 feet above sea level. Guava is generally propagated by seed and is very difficult to root from cuttings. Grafting and budding of desirable guava scion cultivars on superior rootstock, however, may be no more difficult than such fruits as mango and avocado.

Guava is one of those plants that can possibly be made to bear fruit during the first season after budding and planting in the field. Basic research indicates that guava may be manipulated to "fruit on cue" in order to expand fruiting of a field over every month of the year by cycling some trees "in" each month. Consequently, an orchard that is carefully planned and timely pruned would normally provide fruit harvest throughout the year under most favorable conditions.

Depending on climate, cultivar and management practices, it takes approximately 4 to 6 months from flower emergence to fruit ripening on trees. There could be 2 to 3 harvest seasons of tree-ripe fruit in one year when all climatic requirements are met. The best eating quality of fruit generally occurs when it ripens during dry conditions. It has been reported that five-year-old guava trees can produce from 300 to 500 pounds of fruit per tree (12 to 20 tons per acre from 80 to 100 trees). Storage of guava fruit varies from a few days at room temperature to more than 5 weeks at refrigeration below 10° C (50° F) without any significant loss in nutrient content of the fruit.

Current Research

The Fort Valley State University Agricultural Research Station has been engaged in systematic guava research since the late 1980's. Areas studied include growth and development of trees, physiology of cold and frost protection, fruit production feasibility, performance of cultivars, and nutritional quality of tree-ripe fruit produced at the research station.

Innovative methods for growing guava in cooler regions like the Middle Georgia area are presently being examined. Important findings have been disseminated through presentations at professional societies and conferences and in publications in national and international scientific journals.

Future research emphasis will be on biotechnology to develop cold hardy and superior guava lines. This will be accomplished through in vitro studies for guava tissue micro- propagation and genetic transformation to enhance cold hardiness of guava plants, fruit quality characteristics, horticultural values of plants, and their tolerance to biotic and abiotic stresses in the adopted environment.

It appears that the biotechnological research being initiated presently at FVSU will facilitate improvement of guava to enable production of this nutritious exotic fruit in the less frigid temperate climate of Georgia. As the demand for guava increases, its production in Middle Georgia could make a significant contribution in local economies in and around Peach County