Annona crassiflora

Marolo (Annona crassiflora)
Common names	Marolo, araticum, araticum-do-cerrado, pinha-do-cerrado
Scientific name	Annona crassiflora
Family	Annonaceae
Genus	Annona
Order	Magnoliales
Native range	Brazil to Paraguay (Cerrado)
Tree size	About 4–8 m tall with a crown near 4 m across; trunk 20–30 cm thick with thick, fire-resistant bark
Fruit	Compound, subglobose, 90–190 carpels each holding one seed; averages about 1.2 kg in one Mato Grosso population
Uses	Fresh eating, juices, jams, ice creams, liqueurs and cakes

Marolo, also called araticum and known as araticum-do-cerrado or pinha-do-cerrado in parts of Brazil, is the regional name for Annona crassiflora, a small- to medium-sized tree of the Cerrado savanna. The accepted species name is Annona crassiflora, native from Brazil to Paraguay in the seasonally dry tropical biome.^[1] The aromatic pulp is eaten fresh and appears in juices, jams, ice creams, liqueurs and cakes; because commercial plantations do not exist, nearly all fruit comes from extractive harvest of native trees.^[2]

Description

The tree reaches about 4–8 m with a crown of roughly 4 m;^[2] mature trunks are 20–30 cm thick and carry rough, very thick, fire-resistant bark.^[3] Leaves are alternate, distichous, simple and lack stipules.

Flowers of marolo (Annona crassiflora) in Brasília, Federal District, Brazil (October 2009).

Flowers are solitary and axillary, actinomorphic, with three sepals, six petals and numerous stamens and carpels.^[3] The fruit is a compound, multiple infructescence, strobiliform and globose to subglobose, formed by 90–190 carpels fused over a fleshy receptacle, each carpel holding a single seed.^[2] The epicarp is green while immature and turns greenish-brown at ripeness; the pulp is white to yellowish-pink.^[2] In a population sampled at Santo Antônio do Leverger, Mato Grosso (2011), fruits averaged 12.9 cm long, 13.5 cm wide and 12.7 cm thick, weighed 1,187 g and carried 99.2 seeds; the pale-brown, bony, obovoid seeds averaged 17.7 × 10.8 × 8.3 mm.^[3]

Cultivation

Soil and water

The marolo is a Cerrado plant, native to the highly weathered, acidic, low-fertility soils of the savanna. The greenhouse trials behind most nursery guidance used dystrophic Red Latosol with natural base saturation of 8.3%,^[4] and an oxisol (Haplortox) limed to 60% base saturation before fertilization.^[5] Liming to neutralize toxic aluminum and supply calcium and magnesium is part of standard seedling production on these soils.^[4] In container trials, seedling growth and quality rose with liming to 75% base saturation and phosphorus to 400 mg dm−3,^[4] while nitrogen near 100–200 mg dm−3 improved growth, dry mass and quality; potassium mainly improved quality indices and tissue nutrition rather than seedling size.^[5] Watering in those nursery trials was held near 60% of field capacity.^[4] These responses were measured in container-grown seedlings; mature-tree fertility and irrigation response has not been part of the published trials.

Sun and humidity

Native stands grow in the seasonally dry tropical Cerrado, where the climate is hot with rainy summers and a dry winter (roughly April–September); across most of the region annual rainfall is 800–2000 mm and the mean annual temperature is 18–28 °C.^[6] The marolo is therefore accustomed to strong seasonal sun and a pronounced dry season rather than constant humidity. Documented nursery shading is modest: the grafting-compatibility work held plants in a 50% shade nursery with sprinkler irrigation.^[7]

Seasonal changes

Reproduction follows the rain cycle. In southern Minas Gerais, flowering began in late September, fruit set was visible from late October, and peak production came at the end of February and beginning of March; fruits were sampled from 60 to about 145 days after anthesis until abscission, with composition changing most noticeably from about the 120th day.^[8] In Goiânia, over two years, flower emission occurred in two pulses concentrated in the rainy season, and only 3.29% of flowers became fruit — a very low effective fruiting rate attributed to biotic and abiotic factors.^[9] Seed behavior is seasonal in the same way: dormancy is released during the cool, dry months and germination follows the start of the rains (see Propagation).^[6]

Propagation

Seed is the normal route, and dormancy dominates the process. Fresh seeds show non-deep simple morphophysiological dormancy: the embryo is poorly developed at dispersal, the ruminate endosperm is mainly galactomannans, and radicle emergence in the field commonly begins only after about 150 days.^[10] In the Cerrado the dormancy break is tied to weather rather than calendar: seeds buried at Lavras lost physiological dormancy during the cool, dry months (lowest minimum temperatures around May–August), embryo growth started in the first two months of the rainy season (September–October), and germination peaked in November as radicle emergence coincided with the start of the rains; field germination commonly takes 230–300 days.^[6] Germination is epigeous and phanerocotylar; in laboratory sowings germination began about 148 days after sowing and the seedling was fully formed near 190 days.^[3]

Nursery practice documented in Brazilian trials: after about eight months in the sowing bed, soaking seeds for 24 hours in 500 ppm gibberellic acid broke dormancy, with radicle protrusion about 30 days later, and the pre-germinated seedlings were then potted.^[4][5] In vitro, plantlets grew best on WPM with 25–32 mg L−1 GA3, a tissue-culture result rather than an orchard method.^[10] There is no breeding program for the species, and cross-breeding attempts reported in 2009 had not succeeded.^[10]

Grafting is an obvious target because seedlings are slow, but compatibility is poor: araticum scions grafted onto Annona emarginata 'Terra-fria', A. mucosa (biribá) and A. muricata (soursop) rootstocks showed low survival, commonly failing from bud necrosis shortly after grafting. Phenolic compounds concentrated in the araticum cortex, pith and xylem fibers increase on cutting and were identified as the main limiting factor; larger graft diameter and measures to reduce phenolic oxidation are the suggested remedies.^[7]

One grower report conflicts with the published dormancy pattern and is worth flagging as a single observation: a member in Smyrna, Georgia (USDA zone 8a) noted that about 90% of recently acquired seeds germinated within four weeks with sturdy, meaty stems, expecting vigorous growth; seed provenance, age and treatment were not stated. It does not establish a germination standard against the published 150–300-day figures.^[11]

Flowering, fruiting, and harvest

Fruit of araticunzeiro (Annona crassiflora) photographed in rural Araci, Bahia, Brazil (2020).

Flowering and fruiting are compressed into the rainy season. In southern Minas Gerais, flowering began in late September, fruits were first observed at the end of October, and peak production fell in late February to early March, about 145 days after anthesis; the ripe fruit abscises.^[8] Over two years in Goiânia, only 3.29% of flowers produced fruit, so a heavy flower display is a poor predictor of crop.^[9] Ripeness shows as a greenish-brown epicarp with pale, fleshy pulp eaten from the receptacle.^[3]

Wild-collected fruits can be strikingly large. One grower reported obtaining marolo fruits so large that people in the native region called the size unusual; the same thread shows growers preferring to graft from such material rather than raise seedlings.^[12]

Fruit and uses

Marolo pulp is described as strong and slightly sweet. The fruit is among the 20 most-used species in regional foodstuffs, eaten fresh and processed into juices, jams, ice creams, popsicles, liqueurs and cakes.^[2] Per 100 g of pulp, a 2023 review of published analyses lists 95.12 kcal, 1.52 g protein, 3.50 g fat, 14.39 g carbohydrate, 6.80 g dietary fiber and 5.23 mg ascorbic acid.^[2] Seed preparations appear in regional folk medicine for digestive complaints and other traditional uses.^[2][6]

Marolo fruit at a São Paulo market (2012).

The grower-relevant safety note is the acetogenin content. In the first published analysis of marolo, lyophilized fruit pulp held annonacin at 0.334 mg/g dry weight and squamocin at 0.403 mg/g, while seeds held 5.905 mg/g annonacin and 142 mg/g squamocin — far more than the pulp. Annonacin and squamocin are neurotoxic acetogenins, and the epidemiological links to atypical parkinsonism come from over-consumption of graviola (Annona muricata), not marolo; marolo itself was not tested for neurotoxicity, and the single-fruit samples from two markets limit quantitative generalization.^[13]

Photos

References

• ↑ [1] Annona crassiflora — Plants of the World Online (Kew).

• ↑ [2] Scientific advances in the last decade on the recovery, characterization, and functionality of bioactive compounds from the araticum fruit (Annona crassiflora) — Plants 12(7):1536 (2023).

• ↑ [3] Morphological characterization of fruits, seeds and seedlings of araticum plant (Annona crassiflora — Annonaceae) — Journal of Seed Science 35(4):524–531 (2013).

• ↑ [4] Phosphate fertilization and liming promote the growth and development of Annona crassiflora — Floresta e Ambiente (2020).

• ↑ [5] Nitrogen and potassium fertilization in the initial growth of Annona crassiflora — Floresta e Ambiente (2019).

• ↑ [6] Germination ecophysiology of Annona crassiflora seeds — Annals of Botany 99(5):823–830 (2007).

• ↑ [7] Anatomy and histochemistry of araticum (Annona crassiflora) on three Annonaceae rootstocks — American Journal of Plant Sciences 5 (2014).

• ↑ [8] Characterization of chemical and mineral composition of marolo (Annona crassiflora) during physiological development — Food Science and Technology 37(1):13–18 (2017).

• ↑ [9] Araticum reproductive phenology and its implications for productive potential — Comunicata Scientiae 6(4):495–500 (2015).

• ↑ [10] In vitro seed germination and seedling development of Annona crassiflora — Scientia Agricola 66(3):396–400 (2009).

• ↑ [11] Tropical Fruit Forum — experience growing rare species of annona (thread 46101).

• ↑ [12] Tropical Fruit Forum — Real Giant Marolo, Annona crassiflora (thread 14432).

• ↑ [13] Annonacin and squamocin contents of pawpaw (Asimina triloba) and marolo (Annona crassiflora) fruits and atemoya (A. squamosa × A. cherimola) seeds — Biological Trace Element Research (2021).

Image credits

• File:Annona crassiflora fruit.jpg — Mature fruit of marolo photographed in Brasília, Federal District, Brazil (October 2009). Creator: João Medeiros, CC BY 2.0 (license). File page: Wikimedia Commons. Attribution: João Medeiros, CC BY 2.0, via Wikimedia Commons.

• File:Annona crassiflora flower.jpg — Flowers of marolo photographed in Brasília, Federal District, Brazil (October 2009). Creator: João Medeiros, CC BY 2.0 (license). File page: Wikimedia Commons. Attribution: João Medeiros, CC BY 2.0, via Wikimedia Commons.

• File:Fruto da Árvore Araticunzeiro.jpg — Fruit of araticunzeiro photographed in rural Araci, Bahia, Brazil (2020). Creator: GildasioOliveira, CC BY-SA 4.0 (license). File page: Wikimedia Commons. Attribution: GildasioOliveira, CC BY-SA 4.0, via Wikimedia Commons.

• File:Marolo.JPG — Marolo fruit at a São Paulo market (2012). Creator: Niccaballero, public domain (public-domain mark). File page: Wikimedia Commons. Attribution: not required (public domain).

• File:Araticum.JPG — Whole fruit of araticum (Annona crassiflora), photographed 2007. Creator: Fernando Tatagiba, CC BY 3.0 (license). File page: Wikimedia Commons. Attribution: Fernando Tatagiba, CC BY 3.0, via Wikimedia Commons.

• File:Annona crassiflora1.jpg — Annona crassiflora at Entre Rios de Minas, Minas Gerais, Brazil (December 2017; file page does not identify the plant part). Creator: Evaldo Resende, CC BY-SA 4.0 (license). File page: Wikimedia Commons. Attribution: Evaldo Resende, CC BY-SA 4.0, via Wikimedia Commons.