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

Azadirachta indica; neem

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

n

3.05

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

n=0

n

4.01

Produces spines, thorns or burrs

y=1, n=0

n

4.02

Allelopathic

y=1, n=0

4.03

Parasitic

y=1, n=0

n

4.04

Unpalatable to grazing animals

y=1, n=-1

n

4.05

Toxic to animals

y=1, n=0

n

4.06

Host for recognized pests and pathogens

y=1, n=0

n

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

y

4.11

Climbing or smothering growth habit

y=1, n=0

n

4.12

Forms dense thickets

y=1, n=0

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

y

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

n

6.07

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

See left

4

7.01

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

y=1, n=-1

n

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

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

Total score:

5

Source

Notes

1.01

no evidence

1.02

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.40.

" The naturalization of A. indica" in the countries adjacent to the Indian continent, which includes Thailand, some part of Malaysia, Java, and Bali (Now Indonesia) and probably east Africa, can be explained on the basis of the long cultural and commercial relations that these areas have had with India since ancient times."

1.03

no evidence

2.01

CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International.

Review of natural distribution
There is much confusion in the literature about the natural distribution of A. indica. It is considered to be native to dry areas in India, Pakistan, Myanmar, Sri Lanka, Afghanistan, Bangladesh and China (Abdulla, 1972; Tewari, 1992; Vietmeyer, 1992; Gupta, 1993). In India and Pakistan, A. indica occurs naturally in dry deciduous and thorn forests (Champion et al., 1965). It is cultivated as well as naturalized in Thailand, Malaysia and Indonesia. Its altitudinal range is 0-1500 m (Tewari, 1992; Webb et al., 1984).
Natural latitude range
Approximate limits north to south: 25 degree N to 5 degreee N
Vegetation types:
dry forests; deciduous forests; moist forests; mixed forests
List of countries with natural populations
Asia, Afghanistan, Bangladesh, China, India, Indonesia, Malaysia, Myanmar, Pakistan, Sri Lanka, Thailand
Location of introductions
A. indica has been successfully planted in Sudan, Saudi Arabia and Sahelian zones of Africa as well as in Mauritania, Somalia, Sier

2.02

2.03

CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International.

"Its altitudinal range is 0-1500 m"
(1)Tewari DN, 1992. Monograph on neem (Azadirachta indica A. Juss.). 1992, vi + 279 pp.; 669 ref. (2)Webb DB, Wood PJ, Smith JP, Henman GS, 1984. A guide to species selection for tropical and sub-tropical plantations. Tropical-Forestry-Papers,-Commonwealth-Forestry-Institute,-University-of-Oxford. 1984, No. 15 (rev.), ii + 256 pp.; 175 ref.

2.04

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.41.

distribution: India (native); South East Asia, East Africa, Caribbean Islands, Queensland, California, South Florida (introduced)

2.05

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.41.

Introduced to various countries in South East Asia, East Africa, Caribbean Islands, Queensland of Australia, California & South Florida of USA.

3.01

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.40.

" The naturalization of A. indica" in the countries adjacent to the Indian continent, which includee Thailand, some part of Malaysia, Java, and Bali (Now Indonesia) and probably east Africa, can be explained on the basis of the long cultural and commercial relations that these areas have had with India since ancient times."

3.02

no evidence

3.03

Holme et al. (Geographic atlas of world weeds) lists it as "present" in India (native range). Not given weed status

3.04

no evidence

3.05

no evidence

4.01

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.11.

no description of theses traits

4.02

(1)Gurusamy, A.; Kathiresan, R.; Ganesaraja, V.; Raveendran, M. (2000) Allelopathic potential of paddy seeds and some plant products on barnyard grass. Journal of Phytological Research, 2000, Vol.13, No.1, pp.89-90, 2 ref.
(2) Alam, S. M. (1990) Effect of wild plant extracts on germination and seedling growth of wheat. Rachis, 1990, Vol.9, No.2, pp.12-13, 7 ref.
(3) Dhawan, S. R.; Poonam Dhawan (1995) Biocontrol of congress grass: studies on seed germination. World Weeds, 1995, Vol.2, No.1, pp.3-9, 28 ref.
(4)http://www.ajtsc.com/bahama.htm

LAB EXTRACTS, ALL IRRELEVENT TO FIELD SITUATION. (1)AB: The allelopathic effects of rice seeds, neem (Azadirachta indica ) cake, sugarcane press mud and press mud slurry on the growth and establishment of Echinochloa crus-galli were determined. Soaking E. crus-galli seeds with rice seeds resulted in increased germination percentage compared to the control (water-soaked), but all other treatments decreased the dry matter accumulation and germination of E. crus-galli seeds.
(2)AB: The effects of Cassia angustifolia, Sphaeranthus indicus and Azadirachta indica leaf extracts on wheat cv. Sarsabz seed germination and seedling growth were investigated. Germination was unaffected by the extracts but shoot growth was significantly increased by increasing extract concentration. C. angustifolia showed the largest increase (40%) followed by A. indica (30%) and S. indicus (12%). Root growth was decreased significantly as extract concentration increased.
(3) AB: Experiments were conducted to assess the allelopath

4.03

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.10.

evergreen tree

4.04

Koul, O.; Isman, M. B.; Ketkar, C. M. (1990) Properties and uses of neem, Azadirachta indica. Canadian Journal of Botany, 1990, Vol.68, No.1, pp.1-11, 164 ref.

AB: The versatility of the neem tree, Azadirachta indica, is reviewed. This species, native to India, grows in nutrient-poor soils in arid habitats unfavourable to most other crop plants. Various derivatives of the tree have potential use in toiletries, pharmaceuticals, the manufacture of agricultural implements and furniture, cattle, sheep and poultry feeds, nitrification of soils for various agricultural crops and pest control. Since neem is a natural renewable resource producing extensive useful biomass, its propagation and economic exploitation will be beneficial, particularly to the Third World. Lines of research on this plant species are suggested.

4.05

Koul, O.; Isman, M. B.; Ketkar, C. M. (1990) Properties and uses of neem, Azadirachta indica. Canadian Journal of Botany, 1990, Vol.68, No.1, pp.1-11, 165 ref. 2)http://www.winrock.org/forestry/factpub/Factsh/NeemUses.htm

AB: The versatility of the neem tree, Azadirachta indica, is reviewed. This species, native to India, grows in nutrient-poor soils in arid habitats unfavourable to most other crop plants. Various derivatives of the tree have potential use in toiletries, pharmaceuticals, the manufacture of agricultural implements and furniture, cattle, sheep and poultry feeds, nitrification of soils for various agricultural crops and pest control. Since neem is a natural renewable resource producing extensive useful biomass, its propagation and economic exploitation will be beneficial, particularly to the Third World. Lines of research on this plant species are suggested. 2)Neem compounds have been judged to be relatively non-toxic to mammals.

4.06

CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International.

Pests recorded
Insect pests:
Aonidiella orientalis
Solenopsis
Fungus diseases:
Fusarium oxysporum
Glomerella cingulata [1]
Pseudocercospora subsessilis [2]
Footnotes:
1. A teleomorph of Colletotrichum gloeosporioides
2. India and elsewhwere, defoliator

4.07

http://www.winrock.org/forestry/factpub/Factsh/NeemUses.htm

Neem compounds have been judged to be relatively non-toxic to mammals.

4.08

no evidence

4.09

CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International.

"A. indica is a light demander but it also tolerates fairly heavy shade during its early development. "

4.1

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.43.

"Mohan et al observed that neemgrew best on clay soil"; "The neem tree was found superiorin enriched sandy and loamy soil with calcium and in increasing soil pH"

4.11

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.10.

tree

4.12

Decher, J.; Bahian, L. K.1999. Diversity and structure of terrestrial small mammal communities in different vegetation types on the Accra Plains of Ghana. Journal of Zoology, , Vol.247, No.3, pp.395-408

An attempt to measure the impact of the invading exotic tree Azadirachta indica (neem tree) on small mammals was inconclusive, although trapping success was low in areas with dense stands of neem. [is a "dense stand" indication of "dense thicket"]

5.01

CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International.

A. indica is a medium to large, deep-rooted tree. It is almost evergreen and has wide spreading branches forming a rounded or oval dense crown. It grows to a height of 12-15 m, in rare cases up to 30 m, with a short, straight bole 3-7.5 m long and 1.5-2.8 m in girth. The tree generally branches early in life, forming a broad round crown of bright green foliage.

5.02

Meliaceae

5.03

no evidence

5.04

CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International.

A. indica is a medium to large, deep-rooted tree. It is almost evergreen and has wide spreading branches forming a rounded or oval dense crown. It grows to a height of 12-15 m, in rare cases up to 30 m, with a short, straight bole 3-7.5 m long and 1.5-2.8 m in girth. The tree generally branches early in life, forming a broad round crown of bright green foliage.

6.01

no evidence

6.02

Rajiv Rai (1996) To study the efficacy of different nursery raising techniques in neem (Azadirachta indica ). Journal of Tropical Forestry, 1996, Vol.12, No.4, pp.183-188, 16 ref.

AB: "The first part of the paper discusses published work which indicates that neem seeds are short lived, being viable for a period of only 8-10 days from the date of collection, so that they are difficult to propagate in the nursery."

6.03

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.17.

"In some areas, hybridization has occurred between A. indica and A. siamensis"

6.04

Gupta, V. K.; Solanki, K. R.; Gupta, R.; Kumar, R. V.; Datta, A. (1996) Reproductive biology of neem (Azadirachta indica A. Juss). Range Management & Agroforestry, 1996, Vol.17, No.2, pp.187-192, 8 ref.

AB: From studies on pollen dehiscence time, flower anthesis, pollen germination, fruit setting in selfed and open pollinated flowers and progeny performance of selfed and open pollinated seeds it is suggested that neem (Azadirachta indica ) may be a self pollinated tree species.

6.05

National Research Council (1992) Neem: A Tree For Solving Global Problems. National Acadey Press, Washiongton D.C. 141pp. P.23

" The small, white, bisexual flowers are born in axillary clusters. They have honeylike scent and attract many bees."

6.06

no evidence, not important

6.07

National Research Council (1992) Neem: A Tree For Solving Global Problems. National Acadey Press, Washiongton D.C. 141pp. P.25

" A neem tree normally begins bearing fruit after 3-5 years, become fully productive in 10 years, and from then on can produce up to 50 kg of fruits annually." (seed maturation takes several months)

7.01

no evidece

7.02

CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International.

"It is cultivated as well as naturalized"

7.03

no evidence

7.04

no evidence

7.05

no evidence

7.06

1) Primarily dispersed by bats Mabberley. 1998. The Plant Book. Cambridge University Press. 2)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.16.

1)Primarily dispersed by bats 2)"Occasionally, some fruits are swallowed by birds for their sweet pulp and the seeds are passed passed out of the body, undigested, because of the hard endocarp"

7.07

no evidence

7.08

Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.16.

"Occasionally, some fruits are swallowed by birds for their sweet pulp and the seeds are passed passed out of the body, undigested, because of the hard endocarp"

8.01

Read M.D. & French, J.H. Eds. (1993) Genetic Improvement of Neem: Stretegy for the Future. Proc. of the International Consultation on Neem Improvement held at Kasetsart University Bankok, Thailand, 18-33 January, 1993. Winrock International. Bankok, Thailand.

(1)p.9 "A mature tree produces 30-50 kg seed every year." (2) p.29 "100 seed weight from 17.4-29.5g" [(30000 to 50000g/tree*100 seed/23.45g =127931 to 213219 seed/tree] If a mature tree occupies less than 127 to 213 square meter than seed production will be more than 1000 seed/square meter. I think it is very likely. [Borderline -- 1 seed per drupe but often referred to as "a prolific seeder", e.g. http://www.winrock.org/forestry/factpub/factsh/NEEM.HTM]

8.02

Read M.D. & French, J.H. Eds. (1993) Genetic Improvement of Neem: Stretegy for the Future. Proc. of the International Consultation on Neem Improvement held at Kasetsart University Bankok, Thailand, 18-33 January, 1993. Winrock International. Bankok, Thailand.

8.03

no evidence

8.04

National Research Council (1992) Neem: A Tree For Solving Global Problems. National Acadey Press, Washiongton D.C. 141pp. P.23

"The roots penerate the soil deeply , at least where the site permit, and particularly when injured, they produced suckers. This sucking tends to be especially prolific in dry localities"

8.05

no evidence