Thefruit is spherical-conical, 5–10 centimetres (2–4 inches) in diameter and 6–10 cm (2+1⁄4–4 in) long, and weighing 100–240 grams (3.5–8.5 ounces), with a thick rind composed of knobby segments. The colour is typically pale green through blue-green, with a deep pink blush in certain varieties, and typically has abloom. It is unique amongAnnona fruits in being segmented; the segments tend to separate when ripe, exposing the innards.
The flesh is fragrant and sweet, creamy white through light yellow, and resembles and tastes likecustard. The seeds are coated with the flesh, It is found adhering to13-to-16-millimetre-long (1⁄2 to5⁄8 in) seeds forming individual segments arranged in a single layer around a conical core. It is soft, slightly grainy, and slippery. The hard, shiny seeds may number 20–40 or more per fruit and have a brown to black coat, although varieties exist that are almost seedless.[12][13] The seeds can be ground for use as aninsecticide, although this has not been approved by theUS EPA or EU authorities.[8]The stems run through the centre of the fruit connecting it to the outside. The skin is shaped like aReuleaux triangle coloured green and rough in texture. Due to the soft flesh and structure of the sugar apple it is very fragile to pressure when ripe.
New varieties are also being developed inTaiwan and Hong Kong. Theatemoya or "pineapple sugar-apple", a hybrid between the sugar-apple and thecherimoya, is popular in Taiwan, although it was first developed in theUnited States in 1908. The fruit is similar in sweetness to the sugar-apple, but has a very different taste. As its name suggests, it tastes like pineapple.
Branches with light brown bark and visible leaf scars; inner bark light yellow and slightly bitter; twigs become brown with light brown dots (lenticels – small, oval, rounded spots upon the stem or branch of a plant, from which the underlying tissues may protrude or roots may issue).[6]
Thin, simple, alternateleaves[11] occur singly,[6]5 to 17 centimetres (2 to6+3⁄4 inches) long and2 to 6 cm (3⁄4 to2+3⁄8 in) wide;[10][6] rounded at the base and pointed at the tip (oblong-lanceolate).[10] They are pale green on both surfaces and mostly hairless[6] with slight hairs on the underside when young.[7] The sides sometimes are slightly unequal and the leaf edges are without teeth, inconspicuously hairy when young.[6][11]
The leaf stalks are0.4 to 2.2 cm (1⁄8 to7⁄8 in) long,[10] green, and sparsely pubescent.[6]
Solitary or in short lateral clusters of 2–4 about 2.5 cm (1 in) long,[10] greenish-yellow flowers on a hairy, slender[6]2 cm (3⁄4 in) long stalk.[10] Three green outer petals, purplish at the base, oblong,1.6 to 2.5 cm (5⁄8 to 1 in) long, and0.6 to 0.75 cm (1⁄4 to5⁄16 in) wide, three inner petals reduced to minute scales or absent.[7][10] Very numerous stamens; crowded, white, less than1.6 cm (5⁄8 in) long; ovary light green. Styles white, crowded on the raised axis. Each pistil forms a separate tubercle (small rounded wartlike protuberance), mostly1.3 to 1.9 cm (1⁄2 to3⁄4 in) long and0.6 to 1.3 cm (1⁄4 to1⁄2 in) wide which matures into the aggregate fruit.[6]
Flowering occurs in spring-early summer[10] and flowers are pollinated bynitidulid beetles.[14] Its pollen is shed as permanent tetrads.[15]
Aggregate and soft fruits form from the numerous and loosely united pistils of a flower[6] which become enlarged[10] and mature into fruits which are distinct from fruits of other species ofgenus[6] (and more like a giantraspberry instead).
The round or heart-shaped[6] greenish yellow, ripened aggregate fruit is pendulous[10] on a thickened stalk;5 to 10 cm (2 to3+7⁄8 in)[6][7] in diameter[10][11] with many round protuberances[6] and covered with a powdery bloom. Fruits are formed of loosely cohering or almost free carpels (the ripened pistels).[7]
The pulp is white tinged yellow,[7] edible and sweetly aromatic. Each carpel containing an oblong, shiny and smooth,[6] dark brown[7] to black,1.3 to 1.6 cm (1⁄2 to5⁄8 in) long seed.[6]
Sugar-apple is high inenergy, an excellent source ofvitamin C and manganese, a good source of thiamine and vitamin B6, and provides vitamin B2, B3 B5, B9, iron, magnesium, phosphorus and potassium in fair quantities.[19]
Bayer AG has patented the extraction process and molecular identity of the annonaceousacetogeninannonin, as well as its use as abiopesticide, although this use has not been approved byUS or EU authorities.[23] Other acetogenins have been isolated from the seeds,[24] bark,[25] and leaves.[citation needed]
Annona squamosa is native to the tropical Americas and West Indies, but the exact origin is unknown. It is now the most widely cultivated of all the species ofAnnona, being grown for its fruit throughout the tropics and warmer subtropics, such asIndia,Indonesia,Thailand,Taiwan, andChina as far north asSuzhou;[26] it was introduced to southernAsia before 1590. It isnaturalized as far north as southernFlorida in theUnited States and as far south asBahia inBrazil, and is aninvasive species in some areas.[6][9][11]
Like most species ofAnnona, it requires a tropical or subtropical climate with summer temperatures from 25 °C (77 °F) to 41 °C (106 °F), and mean winter temperatures above 15 °C (59 °F). It is sensitive to cold and frost, being defoliated below 10 °C (50 °F) and killed by temperatures of a couple of degrees below freezing. It is only moderatelydrought-tolerant, requiring at least 700 millimetres (28 in) of annual rainfall, and does not produce fruit well during droughts.
It will grow from sea level to an altitude of 2,000 metres (6,600 feet) and thrives in hot dry climates, differing in its tolerance of lowland tropics from many of the other fruit bearers in theAnnona family.
It is quite a prolific bearer, and it produces fruit within as little as two to three years. A five-year-old tree can produce as many as 50 sugar apples. Poor fruit production has been reported in Florida because there are few natural pollinators (honeybees have a difficult time penetrating the tightly closed female flowers); however, hand pollination with a natural fibre brush is effective in increasing yield. Natural pollinators include beetles (coleoptera) of the familiesNitidulidae,Staphylinidae,Chrysomelidae,Curculionidae andScarabaeidae.[9][13]
In traditional Indian, Thai, and Native American medicines, the leaves are boiled down with water, possibly mixed with other specific botanicals, and used in adecoction to treatdysentery andurinary tract infection.[27] Intraditional Indian medicine, the leaves are also crushed for use as a poultice, and applied to wounds.[27] In Mexico, the leaves are rubbed on floors and put in hens' nests, to repel lice.[9]InHaiti, the fruit is known ascachiman and is used to simply make juice.[28]
^abcdMorton, Julia (1987)."Sugar AppleAnnona squamosa".Fruits of warm climates. Department of Horticulture & Landscape Architecture, Purdue University. p. 69.Archived from the original on 5 April 2008. Retrieved2008-04-17.
^Walker JW (1971) Pollen Morphology, Phytogeography, and Phylogeny of the Annonaceae. Contributions from the Gray Herbarium of Harvard University, 202: 1-130.
^Panda S, Kar A (2007). "Antidiabetic and antioxidative effects ofAnnona squamosa leaves are possibly mediated through quercetin-3-O-glucoside".BioFactors.31 (3–4):201–210.doi:10.1002/biof.5520310307.PMID18997283.S2CID38336427.
^Chen Y, Xu SS; et al. (2012). "Anti-tumor activity ofAnnona squamosa seeds extract containing annonaceous acetogenin compounds".Journal of Ethnopharmacology.142 (2):462–466.doi:10.1016/j.jep.2012.05.019.PMID22609808.
^Li XH, Hui YH; et al. (1990). "Bullatacin, bullatacinone, and squamone, a new bioactive acetogenin, from the bark ofAnnona squamosa".Journal of Natural Products.53 (1):81–86.doi:10.1021/np50067a010.PMID2348205.