Soursop (Annona muricata) i.e. laxmanphal is related to sweetsop or sugar-apple(Annona squamosa) i.e. seethaphal.
Soursop is also known as graviola,guanabana and Brazilian pawpaw.Its flavor has been described as a combination of strawberry and pineapple with sour citrus flavor notes contrasting with an underlying creamy flavor reminiscent of coconut or banana.
The flesh of the fruit consists of an edible, white pulp, some fiber, and a core of indigestible, black seeds. This species is the only member of its genus that is suitable for processing and preservation.
Nutritionally, the fruit is high in carbohydrates, particularly fructose. The fruit also contains significant amounts of vitamin C, vitamin B1, and vitamin B2.
The soursop tree is low-branching and bushy but slender because of its upturned limbs, and reaches a height of 25 or 30 ft. The malodorous leaves, normally evergreen, are alternate, smooth, glossy, dark green on the upper surface, lighter beneath; oblong, elliptic or narrow obovate, pointed at both ends, 2 1/2 to 8 in long and 1 to 2 1/2 in wide. The flowers, which are borne singly, may emerge anywhere on the trunk, branches or twigs. They are short stalked, 1 1/2 to 2 in long, plump, and triangular-conical, the 3 fleshy, slightly spreading, outer petals yellow-green, the 3 close-set inner petals pale-yellow.
The fruit is more or less oval or heart-shaped, some times irregular, lopsided or curved, due to improper carper development or insect injury. The size ranges from 4 to 12 in long and up to 6 in in width, and the weight may be up to 4.5-6.8 kg. The fruit is compound and covered with a reticulated, leathery-appearing but tender, inedible, bitter skin from which protrude few or many stubby, or more elongated and curved, soft, pliable "spines". The tips break off easily when the fruit is fully ripe. The skin is dark-green in the immature fruit, becoming slightly yellowish-green before the mature fruit is soft to the touch. In each fertile segment there is a single oval, smooth, hard, black seed, l/2 to 3/4 in long; and a large fruit may contain from a few dozen to 200 or more seeds.
The soursop is truly tropical. Where the tropical jackfruit thrives, the soursop is perfectly at home. The tree is said to prefer an altitude between 800 and 1,000 ft , with moderate humidity, plenty of sun and shelter from strong winds.
Best growth is achieved in deep, rich, well-drained, semi-drysoil, but the soursop tree can be and is commonly grown in acid and sandy soil, and in the porous, oolitic limestone.
The soursop is usually grown from seeds. They should be sown in flats or containers and kept moist and shaded. Germination takes from 15 to 30 days. Selected types can be reproduced by cuttings or by shield-budding.
In ordinary practice, seedlings, when 1 ft or more in height are set out in the field at the beginning of the rainy season and spaced 12 to 15 ft apart, though 25 ft each way has been suggested. A spacing of 20 x 25 ft (6x7.5 m) allows 87 trees per acre The tree grows rapidly and begins to bear in 3 to 5 years. Mulching is recommended to avoid dehydration of the shallow, fibrous root system during dry, hot weather.
In southern India, it extends from June to September.
The fruit is picked when full grown and still firm but slightly yellow-green. If allowed to soften on the tree, it will fall and crush. It is easily bruised and punctured and must be handled with care. Firm fruits are held a few days at room temperature. When eating ripe, they are soft enough to yield to the slight pressure of one's thumb. Having reached this stage, the fruit can be held 2 or 3 days longer in a refrigerator.
Pests & Diseases
The fruit is subject to attack by fruit flies—Anastrepha suspensa, A. striata and Ceratitis capitata. Red spiders are a problem in dry climates.