Psidium cattleianum - Usambara Invasive Plants

Common names: Strawberry guava, cattley guava, cherry guava, Chinese guava, purple guava, pineapple guava

Synonyms: Psidium littorale Raddi, Psidium cattleianum var. littorale (Raddi) Mattos

Life form: Shrub/ small tree

Biology/Ecology:

Dispersal: Fruits dispersed by birds, pigs, cattle and monkeys. Disperses vegetatively by suckers and root sprouts. Introduced by humans to be grown for its edible fruit.

Reproduction: White flowers are borne solitary in leaf axils. Produces many red fruits of 20-35 mm diameter, containing up to 70 seeds with length of 3 mm.

Herbivores: No information available.

Resistant stages: No information available.

Habitat:

Native habitat: Tropical moist forest

Habitat occupied in invaded range: Montane, tropical and subtropical rainforests, mountain slopes, scrub, grassland, and disturbed areas.

Habitat requirements:

Altitude	Below 1500 metres above sea level, but is most abundant below 800 metres.
Light	Prefers full sun but is highly shade tolerant.
Temperature	No information available.
Annual rainfall	Between 1250 and 7000 mm.
Soil	No information available.

Distribution:

Native to Brazil.

Introduced range: Invasive in southern Africa, Tanzania, Australia, New Zealand, southeastern USA and many Pacific and Indian Ocean Islands, in particular Mauritius and Hawaii. Introduced but not invasive in parts of tropical Africa and the Azores.

Impacts:

Ecosystem: The plant is fast growing and produces many fruit. Being shade tolerant, the plant can invade the understorey of undisturbed forest and form thickets and root suckers, outcompeting native plants and eventually forming monotypic stands. The plant rapidly invades disturbed forest, inhibiting regeneration of native trees. Mats of feeder roots on the soil surface and a large amount of litter suppress the growth of native seedlings. The plant is thought to have allelopathic qualities. The plant has a high fruit production, which helps to sustain high populations of vertebrates such as pigs and monkeys, which often damage native plants outside of the Psidium cattleianum fruiting season.

Health, social and economic: The edible fruit of the plant is often appreciated by local people, and can be a source of income for farmers.

Management:

Mechanical: Seedlings and saplings can be dug out. Larger trees should be cut and the stumps treated with a herbicide to prevent resprouting. Fencing off invaded areas reduces the spread of seeds by vertebrates. Control of exotic invertebrates such as feral pigs that spread the seeds may limit the spread of P. cattleianum.

Chemical: The following methods have been reported as being successful:

Foliar applications of triclopyr, dicamba and 2,4-D are effective in dry conditions.

Cut-stump applications of undiluted picloram and triclopyr ester are effective in dry conditions.

Undiluted dicamba is highly effective as cut surface treatment.

Undiluted glyphosate has been effective as hack-and-squirt method.

Triclopyr is recommended because of its lack of mobility and short half-life.

Biological: Investigations are currently trying to identify insect species that will attack strawberry guava but not common guava, as these two species are sympatric in their natural range.

References:

Weber, E., 2003. Invasive Plant Species of the World: A Reference Guide to Environmental Weeds. CABI Publishing, Wallingford, UK.

Mauremootoo, J., Rodriguez, J., Mauritian Wildlife Foundation and ISSG, 2006. Psidium cattleianum (shrub, tree). Global Invasive Species Database. Available from http://www.issg.org/database/species/ecology.asp?si=59&fr=1&sts=sss (Accessed August 2006).

Pacific Island Ecosystems at Risk (PIER), 2005. Available from http://www.hear.org/Pier/species/psidium_cattleianum.htm (Accessed August 2006).

Lyons, E.E. and Miller, S.E., 2000. Invasive Species in Eastern Africa: Proceedings of a workshop held at ICIPE, July 5-6, 1999. ICIPE Science Press. Available from http://www.gisp.org/publications/workshops/EastAfrica.pdf (Accessed August 2006).

Tunison, T., 1991. Element Stewardship Abstract for Psidium cattleianum. The Global Invasive Species Initiative, The Nature Conservancy. Available from http://tncweeds.ucdavis.edu/esadocs/documnts/psidcat.html (Accessed August 2006).

Last updated October 2006

Back to Species Descriptions

Taxon	Family
Psidium cattleianum Sabine	Myrtaceae


The shrub bearing fruit Credit: Forest & Kim Starr	A dense grove in invaded habitat Credit: The Nature Conservancy