The Guava (Psidium guajava L., Myrtaceae), is one of 150 species of Psidium most of which are fruit bearing trees native to tropical and subtropical America. The guava plant grows symmetrically dome-shaped with broad, spreading, low-branching canopy and a shallow-rooted small tree of 3 to 10 m in height, branching close to the ground and often heavily suckering from the base of the trunk. The green to reddish-brown and smooth bark on older branches and trunk peels off in thin flakes. The four-angled young twigs of guava are easily distinguished. The simple leaves of guava are opposite, 10 to 15 cm long, oval to oblong-elliptic, smooth, and light green in color.
The fruit, exuding a strong, sweet, musky odor when ripe, may be round, ovoid, or pear-shaped, 2 to 4 in (5-10 cm) long, with 4 or 5 protruding floral remnants (sepals) at the apex; and thin, light-yellow skin, frequently blushed with pink. Next to the skin is a layer of somewhat granular flesh, 1/8 to 1/2 in (3-12.5 mm) thick, white, yellowish, light- or dark-pink, or near-red, juicy, acid, subacid, or sweet and flavorful. The central pulp, concolorous or slightly darker in tone, is juicy and normally filled with very hard, yellowish seeds, 1/8 in (3 min) long, though some rare types have soft, chewable seeds.
Guava trees are seriously damaged by the citrus flat mite, Brevipa1pus californicus. The guava tree is attacked by 80 insect species, including 3 bark-eating caterpillars (Indarbella spp.) and the guava scale in India, but this and other scale insects are generally kept under control by their natural enemies. The green shield scale, Pulvinaria psidii, requires chemical measures in Florida, as does the guava white fly, Trialeurodes floridensis, and a weevil, Anthonomus irroratus, which bores holes in the newly forming fruits. See more Pests and Diseases of Guava.
PropagationThe chief pollinator of guavas is the honeybee (Apis mellifera). The amount of cross-pollination ranges from 25.7 to 41.3%. Seed propagation is not practised because of high degree of variation among the progenies. Air layering is widely adopted for propagation of selected varieties. Layers strike roots within 3-5 weeks. When the roots grow through the ball of moss, the stem may be severed below the girdled area in stages. The polythene film is removed from the finally severed rooted stem, which is then potted and kept in the shade until new leaves appear. When the new flushes are produced, the plant can be hardened in full sunlight preparatory to transplanting in the field.
Culture - Land Preparation
- Soil: The guava prefer full sun. They will tolerate many soil conditions, but will produce better in rich soils high in organic matter. They also prefer a well-drained soil in the pH range of 5 to 7. The tree will take temporary waterlogging but will not tolerate salty soils.
- Irrigation: Guavas have survived dry summers with no water in California, although they do best with regular deep watering. The ground should be allowed to dry to a depth of several inches before watering again. Lack of moisture will delay bloom and cause the fruit to drop.
- Pruning: Shaping the tree and removing water shoots and suckers are usually all that is necessary. Guavas can take heavy pruning, however, and can be used as informal hedges or screens. Since the fruit is borne on new growth, pruning does not interfere with next years crop.
- Fertilization: Guavas are fast growers and heavy feeders, and benefit from regular applications of fertilizer. Mature trees may require as much as 1/2 pound actual nitrogen per year. Apply fertilizer monthly, just prior to heavy pruning.
Guava is hardy, aggressive, and a perennial that has only recently become a cultivated crop. It is capable of growing and fruiting under severe competition from other plants. Consequently, weed control efforts in a guava orchard may be only minimal to begin with since control expenditure can become too high. There are several ways weeds can be controlled, however.
- Minimal Control: Eliminate only tall weeds by hand that grow into the crown of the tree or in the space between trees. Eventually, however, such minimal management will result in an unproductive orchard unless further efforts in weed control is expended as cash flow develops.
- Surface Mulching: Mulching at the base of trees can be done very inexpensively using black polyethylene sheets, cinder materials, or organic materials such as wood shavings. The latter two materials should be applied thick enough to prevent weed growth yet permit rainwater penetration to the root area. Black polyethylene sheets prevent soils surface evaporation and tend to produce water under the sheets through condensation, supporting tree growth besides affording weed control.
- Mowing: Mowing throughout the orchard with an off-set tow mower is a good method to eliminate tall, woody plants or grasses. However, this method can become expensive since the weeds at the base of the trees will consumer a large portion of the applied fertilizer, depending on the application technique and available water. In such situations, the total amount of applied fertilizer needs to be increased.
- Herbicide and Mowing: Herbicide around the base of trees with only occasional mowing in the areas between trees is a good method. The herbicide area can be gradually expanded into the mowing area as the trees become larger and older. This method is probably the most economical to use.
- Complete Weed Control with Herbicides: The use of chemical weed control may initially appear expensive, but when properly applied, it can become a good economical method to achieve the gradual elimination of weed seeds and vegetative propagules.
- Raw guavas are eaten out-of-hand, but are preferred seeded and served sliced as dessert or in salads.
- The canned product is widely sold and the shells can also be quick-frozen. They are often served with cream cheese. Sometimes guavas are canned whole or cut in half without seed removal.
- Bars of thick, rich guava paste and guava cheese are staple sweets, and guava jelly is almost universally marketed.
- Guava juice, made by boiling sliced, unseeded guavas and straining, is made into sirup for use on waffles, ice cream, puddings and in milkshakes.
- There are innumerable recipes for utilizing guavas in pies, cakes, puddings, sauce, ice cream, jam, butter, marmalade, chutney, relish, catsup, and other products.
- For pink sherbet, French researchers recommend 2 parts of the cultivar 'Acid Speer' and 6 parts 'Stone'. For white or pale-yellow sherbet, 2 parts 'Supreme' and 4 parts 'Large White'.
- In South Africa, a baby-food manufacturer markets a guava-tapioca product, and a guava extract prepared from small and overripe fruits is used as an ascorbic-acid enrichment for soft drinks and various foods.
- Guavas are mixed with cornmeal and other ingredients to make breakfast-food flakes.
- Green mature guavas can be utilized as a source of pectin, yielding somewhat more and higher quality pectin than ripe fruits.