Psidium guajava

Overview

Widely cultivated in tropical and subtropical regions around the world, guava fruits can range in size from as small as an apricot to as large as a grapefruit. Various cultivars have white, pink, or red flesh, and a few also feature red (instead of green or yellow) skin.

When cultivated from seed, guavas are notable for an extremely slow growth rate for several months, before a very rapid acceleration in growth rate takes over. From seed, common guavas may bloom and set fruit in as few as two years or as many as eight. Cuttings and grafting are more commonly used as a propagation method in commercial groves. Highly adaptable, guavas can be easily grown as container plants in temperate regions, though their ability to bloom and set fruit is somewhat less predictable. In some tropical locations, guavas can become invasive. It has become a major problem in the Galápagos Islands.

The plant is used in many different shampoo products for its scent. It is also becoming a popular bonsai species and is currently quite popular in India and Eastern Asia.

Climate and soil

Owing to its hardy nature, guava is grown successfully in tropical and subtropical regions up to 1,500 m (4,900 ft) above mean sea-level. Best quality guavas are obtained where low night temperatures, 10 °C (50 °F), prevail during winter. It tolerates high temperatures and drought conditions in North India during summers but it is susceptible to severe frost as it can kill the young plants. An annual rainfall of about 100 cm (39 in) is sufficient during the rainy season (July–September). The rains during harvesting period, however, deteriorate the quality of fruits.

Guava is cultivated on varied types of soils- heavy clay to very light sandy soils. Nevertheless, very good quality guavas are produced in river-basins. It tolerates a soil pH of 4.5-8.2. Maximum concentration of its feeding roots is available up to 25 cm (9.8 in) soil depth. Thus the top soil should be quite rich to provide enough nutrients for accelerating new growth which bears fruits.

Varieties

The varietals characteristics in guava are not as distinct as found in most other fruits. Its propagation through seeds reduces the distinctive characteristics of a variety in commercial cultivation. Important guava varieties are:

Also known as Sardar, its fruits are large, roundish ovate in shape, skin primrose yellow and pulp white, very sweet and tasty. The total soluble solids (TSS) and vitamin C contents are high. The trees are vigorous.

The most famous variety of Allahabad, it has acquired large variations due to seed propagation. The fruits are large in size, round in shape, skin smooth and yellowish white. The flesh is white, firm, soft having pleasant flavour, high TSS and vitamin C content. The seeds are numerous, bold and hard. The trees are tall with profuse branching and broad crown. It can withstand drought conditions.

The variety is very popular in western Uttar Pradesh. The fruits are characterized by numerous red dots on the skin, high sweetness, and small and soft seeds. It is otherwise similar to Allahabad safeda fruits in size, shape and pulp. It has higher TSS content than Allahabad Safeda and Lucknow 49 but lower vitamin C content. The tree characters resemble to those of Allahabad Safeda.

Harijha is more popular in Bihar because of profuse bearing. The trees are of medium vigor due to sparse branching. The fruit is round in shape, medium large in size and greenish yellow in color. Flavor is sweet with good keeping quality.

It is a tasty, red- fleshed guava. It is mainly grown in Bihar. The fruit is moderately large and spherical in shape, with thin skin. Trees are of medium vigor but productive.

Its fruits are medium-sized and pink colored. They are sweet in taste with good keeping quality. They require low temperature for the development of good pink color. The trees are of medium vigor but their leaves are greener than others. However, it is a moderate yielder.

(looking like apple) variety low temperature for the development of good pink color. The trees are of medium vigour but their leaves are greener than others. However, it is a moderate yielder.

All the seedless varieties viz. Saharanpur Seedless, Nagpur seedless and others, are the same. Two types of fruits, completely seedless and partly seeded, are borne on a plant of seedless variety. The completely seedless fruits develop on the shoots rising from the stem and these are bigger in size and irregular in shape. The partly seeded fruits are born on normal shoots at the periphery and are small in size and round in shape. Seedless variety is unfit for commercial cultivation because it gives very low yield. The plants are very vigorous.

This is a seedling selection of variety Allahabad Safeda. Its medium-sized fruits are of excellent quality with high TSS. The white pulp has only few soft seeds. The plants are of medium vigor but high yielding.

This is an outstanding variety of large, uniform pink fruits with deep pink flesh. The plants produce up to 120 kg (260 lb) fruits in its sixth year of fruiting. The fruit is sweet, strongly flavored with few seeds and is slightly depressed at both ends. The plants are vigorous, dome shaped and compact.

Chemistry

The leaves of P. guajava contains the flavonol morin, morin-3-O-lyxoside, morin-3-O-arabinoside, quercetin and quercetin-3-O-arabinoside.

Wood

Guava wood from Hawaii is commonly used for the smoking of meat. The wood is resistant to insect and fungal attack. The density of oven-dry wood is about 670 kg/m³ (1,130 lb/cu yd) and has been found suitable for roof trusses in Nigeria.

Traditional medicine

Psidium guajava has been used in traditional medicine in many cultures throughout Central America, the Caribbean, Africa, and Asia. It is used for inflammation, diabetes, hypertension, caries, wounds, pain relief, fever, diarrhea, rheumatism, lung diseases, and ulcers.