Research directed by C. Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service

Information on Risk Assessments
Original risk assessment

Psidium cattleianum

Answer

1.01

Is the species highly domesticated?

y=-3, n=0

n

1.02

Has the species become naturalized where grown?

y=-1, n=-1

y

1.03

Does the species have weedy races?

y=-1, n=-1

n

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

2

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

2

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

y

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

y

2.05

Does the species have a history of repeated introductions outside its natural range? y=-2

?=-1, n=0

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

y

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

n

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

n

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

y

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

y

4.01

Produces spines, thorns or burrs

y=1, n=0

n

4.02

Allelopathic

y=1, n=0

y

4.03

Parasitic

y=1, n=0

n

4.04

Unpalatable to grazing animals

y=1, n=-1

4.05

Toxic to animals

y=1, n=0

n

4.06

Host for recognized pests and pathogens

y=1, n=0

y

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

n

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

n

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

y

4.1

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

n

4.11

Climbing or smothering growth habit

y=1, n=0

n

4.12

Forms dense thickets

y=1, n=0

y

5.01

Aquatic

y=5, n=0

n

5.02

Grass

y=1, n=0

n

5.03

Nitrogen fixing woody plant

y=1, n=0

n

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

6.02

Produces viable seed.

y=1, n=-1

y

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

y

6.05

Requires specialist pollinators

y=-1, n=0

n

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

y

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

3

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

y

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

n

7.04

Propagules adapted to wind dispersal

y=1, n=-1

n

7.05

Propagules water dispersed

y=1, n=-1

n

7.06

Propagules bird dispersed

y=1, n=-1

y

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

7.08

Propagules survive passage through the gut

y=1, n=-1

y

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

y

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

n

8.03

Well controlled by herbicides

y=-1, n=1

y

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

y

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

n

Total score:

18

Source

Notes

1.01

P. cattleianum f lucidum and P.c. var. littoral are mentioned to occur sporadically throughout the range. Although the species is cultivated no evidence that it differs from the wild individuals.

1.02

(1) The species is naturalized in Hawaii. (2) One of the worst invasive species in forests of Hawai'i, Tahiti, La Réunion and Mauritius.

(1) Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu. (2) http://www.hear.org/pier/pscat.htm

1.03

Psidium c. var lucidum occurs sporadically throughout the range in Hawaii. The above mentioned variety is not listed in any of the weed databases checked.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

2.01

It is native to the neotropics and is widely cultivated and naturalized in the tropical and subtropical areas of the world.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

2.02

Native climate is dry to moist tropical. Climate where invading is moist wet tropical and subtropical.

Cronk, Q, C, B, & J. Fuller. 1995. Plant invaders the threat to natural ecosystems. Chapman and Hall. London.

2.03

'A species of wide ecological tolerance …found to an elevation of 1300 m in 23 different vegetation types on the island of Hawaii.'

Pratt L, G. L. Santos, C. P. Stone. 1994. A test of four hesbicides for use on strawberry guava in Kipahulu valley, Haleakala national park. Cooperative National Park Resources studies unit. Technical report 90. University of Hawaii at Manoa.

2.04

It is native to the neotropics and is widely cultivated and naturalized in the tropical and subtropical areas of the world.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

2.05

This species has been introduced to Hawaii, Mauritius, Australasia - Norfolk, Tropical Polynesia.

Cronk, Q, C, B, & J. Fuller. 1995. Plant invaders the threat to natural ecosystems. Chapman and Hall. London.

3.01

(1) The species is naturalized in Hawaii.(2) One of the worst invasive species in forests of Hawai'i, Tahiti, La Réunion and Mauritius.

(1) Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu. (2) http://www.hear.org/pier/pscat.htm

3.02

3.03

3.04

(1) 'The strawberry guava is one of the most serious weeds in Hawaii.' (2) One of the worst invasive species in forests of Hawai'i, Tahiti, La Réunion and Mauritius.(3)This medium-sized tree forms dense thickets, later forming forests under which very few other plants grow. It is the worst pest in Hawai'i's rain forests.

(1) Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu. (2) http://www.hear.org/pier/pscat.htm (3)http://www.botany.hawaii.edu/faculty/cw_smith/psi_cat.htm

3.05

Psidium guajava is considered a serious pest in Hawaii.

Smith, W. S. 1985. Impact on alien plants on Hawaii native biota. In Hawaii's terrestrial ecosystems preservation and management. Eds.C.P. Stone and J. M. Scott. University of Hawaii at Manoa.

4.01

The species does not have any spines, thorns or burrs

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

4.02

''…it is difficult for other plants to establish because of the guava's dense growth and allelopathic properties.'

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

4.03

Did not find any evidence of it being parasitic.

4.04

Don’t know

4.05

Did not find any evidence that it is toxic to animals.

4.06

Did not find any evidence of it being a host for recognized non-gneralist pest. The following are listed under 'fungal-host distribution' Armillariella tabescens: FL - 1
Atichia solaridiscoidea: HI - 146
Biscogniauxia uniapiculata: HI - 32742
Cercospora psidii: FL - 1
Colletotrichum gloeosporioides: FL - 1
Glomerella cingulata: FL - 1
Phytophthora cinnamomi: HI - 1710
Pythium sp.: FL - 1
Scytinostroma decidens: Reunion - 7149
Seuratia globifera: HI - 146
Triscelophorus monosporus: HI - 1710
2) Guava whitefly, guava moth, and Caribbean fruit fly can be major problems in southern Florida

2)http://www.slm.bm/guava.htm

4.07

Did not find any evidence that it is toxic or causes allergies in people.

4.08

'Adaptation to fire is unknown.' Evergreen, unlikely to pose fire hazard.

Smith, W. S. 1985. Impact on alien plants on Hawaii native biota. In Hawaii's terrestrial ecosystems preservation and management. Eds.C.P. Stone and J. M. Scott. University of Hawaii at Manoa.

4.09

'It may occur in large numbers within dense forest, indicating that it is shade tolerant.'

Cronk, Q, C, B, & J. Fuller. 1995. Plant invaders the threat to natural ecosystems. Chapman and Hall. London.

4.1

It can grow in clay and loam type soils.

Plant master 5.5 California edition. CD-ROM database. 1999.

4.11

It is not a vine and although it is known to 'shade out' plants there is no evidence of it having a smothering habit.

Smith, W. S. 1985. Impact on alien plants on Hawaii native biota. In Hawaii's terrestrial ecosystems preservation and management. Eds.C.P. Stone and J. M. Scott. University of Hawaii at Manoa.

4.12

'…in Hawaii naturalized and often forming dense monotypic stands in …'

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

5.01

5.02

5.03

'Shrubs or small trees, 2- 6 m tall…' Did not find any evidence on its ability to fix nitrogen.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

5.04

6.01

Did not find any evidence on reproductive failure in the native habitat.

6.02

Did not find any evidence on the production of non viable seeds.

6.03

Don’t know. Did not find any evidence on hybridization.

6.04

"The trees are self fruitful" 2)Generally self-fruitful, but yields are greater if cross- pollinated. 3)Self-fertile

http://www.naturalhub.com/grow_fruit_and_nuts_in_warm_temperate_areas.htm 2)http://www.edible.co.nz/psidium/Guavayellocherry.htm 3)http://www.edible.co.nz/psidium/Guavayellocherry.htm

6.05

Did not come across any information regarding requirement of specialized pollinators. Simple open flowers visited by bees.

6.06

'A fast growing species capable of spreading by seed or vegetative suckers,…'

Pratt L, G. L. Santos, C. P. Stone. 1994. A test of four hesbicides for use on strawberry guava in Kipahulu valley, Haleakala national park. Cooperative National Park Resources studies unit. Technical report 90. University of Hawaii at Manoa.

6.07

R. Criley, UH Department of Horticulture, Personal communication

7.01

Humans consume fruit along hiking trails, often spitting out seeds.

7.02

Strawberry guava fruits are much relished and hence it is very likely that the species is dispersed intentionally be people.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

7.03

Seeds are relatively big - about 5 mm long - less likely to be introduced as a produce

7.04

7.05

7.06

'It is readily spread by birds and pigs.'

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

7.07

The seeds do not have any mechanism by which they can get attached to animals externally.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

7.08

(1) 'The seeds pass through the digestive tracts unharmed and are often deposited in soil …' (2) Seed do not 'require' to pass through the gut of animals in order to germinate, however passage through the gut shortens the time to germination.

(1) Smith. W. S. 1985. Impact on alien plants on Hawaii native biota. In Hawaii's terrestrial ecosystems preservation and management. Eds.C.P. Stone and J. M. Scott. University of Hawaii at Manoa. (2) Huenneke, L. F. & P. M. Vitousek. 1990. Seedling and clonal recruitment of the inavasive tree Psidium cattleianum: implications for management of native Hawaiian forests. Biological conservation. Vol 53 pg 199-211

8.01

(1) 'The species is a prolific producer of fruit, and sees have a high germination rate … ' (2) 'Prolific seed production all year round.' 3) 25-70 seeds/fruit

Pratt L, G. L. Santos, C. P. Stone. 1994. A test of four hesbicides for use on strawberry guava in Kipahulu valley, Haleakala national park. Cooperative National Park Resources studies unit. Technical report 90. University of Hawaii at Manoa. (2) Cronk, Q, C, B, & J. Fuller. 1995. Plant invaders the threat to natural ecosystems. Chapman and Hall. London. 3)Huenneke, L.F. and P. M. Vitousek. 1989. Seedling and clonal recruitment of the invasive tree Psidium cattleianum: implications for management of native Hawaiian forests. Biological Conservation 53: 199-211.

8.02

The seed laden pig droppings may contribute to the seed bank. But there is no data to support this. The intact seeds from the soil sample failed to germinate in the lab. The authors speculate that this may be because the seeds either germinate quickly or die. Potential recruits probably are concentrated as seedlings bank rather than as dormant seeds.

Huenneke, L. F. & P. M. Vitousek. 1990. Seedling and clonal recruitment of the inavasive tree Psidium cattleianum: implications for management of native Hawaiian forests. Biological conservation. Vol 53 pg 199-211

8.03

The stump treatment with undiluted Garlon 4 is recommended by the authors. However because of re-rooting and less than 100% kill achieved, further research is recommended. 2)A number of effective chemical control measures have been developed. Strawberry guava is sensitive to picloram, dicamba,
glyphosate, and triclopyr. Kageler and Eldredge (1985) found that undiluted picloram (Tordon 22K) was highly effective on strawberry guava as a cut stump treatment. Tordon 22K was used at Hawaii Volcanoes but discontinued because of unfavorable effects on non-target plants. It was replaced by Tordon RTU, which was nearly as effective, but less harmful to surrounding vegetation (Tunison et al. in prep.). Undiluted dicamba (Banvel) proved to be highly effective in a cut surface treatment (Arakaki et al. 1986). Mootoka et al. (1983) found undiluted glyphosate (Roundup) to be effective using a "hack and squirt" method. Cuddihy (pers. comm.) found undiluted triclopyr ester (Garlon 4) to be effective as a cut-stumptreatment,

Pratt L, G. L. Santos, C. P. Stone. 1994. A test of four herbicides for use on strawberry guava in Kipahulu valley, Haleakala national park. Cooperative National Park Resources studies unit. Technical report 90. University of Hawaii at Manoa. 2)http://tncweeds.ucdavis.edu/esadocs/documnts/psidcat.html

8.04

Vigorous regrowth of cut stumps. 'Adaptation to fire is unknown.'

Smith. W. S. 1985. Impact on alien plants on Hawaii native biota. In Hawaii's terrestrial ecosystems preservation and management. Eds.C.P. Stone and J. M. Scott. University of Hawaii at Manoa.

8.05

In Hawaii the prospects for biological control are considered to be slim because of commercial exploitation of common guava. Dr. Smith's alien species webpage for 'biocontrol of guava ' is under construction. It seems like biocontrol of guava is being considered.

Smith. W. S. 1985. Impact on alien plants on Hawaii native biota. In Hawaii's terrestrial ecosystems preservation and management. Eds.C.P. Stone and J. M. Scott. University of Hawaii at Manoa.