Pacific Island Ecosystems at Risk (PIER)
RISK ASSESSMENT RESULTS: High risk, score: 10
Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i. Information on Risk Assessments Original risk assessment |
Azadirachta indica A. Juss. Family - Meliaceae. Common Names(s) - Neem. Synonym(s) - Antelaea azadirachta (L.) Adelb., Melia azadirachta L. |
Answer |
Score |
||
1.01 |
Is the species highly domesticated? |
y=-3, n=0 |
n |
0 |
1.02 |
Has the species become naturalized where grown? |
y=1, n=-1 |
||
1.03 |
Does the species have weedy races? |
y=-1, n=-1 |
||
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 |
1 |
2.04 |
Native or naturalized in regions with tropical or subtropical climates |
y=1, n=0 |
y |
1 |
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 |
2 |
|
3.02 |
Garden/amenity/disturbance weed y = 1*multiplier (see Append 2) |
n=0 |
y |
2 |
3.03 |
Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2) |
n=0 |
||
3.04 |
Environmental weed y = 2*multiplier (see Append 2) |
n=0 |
||
3.05 |
Congeneric weed y = 1*multiplier (see Append 2) |
n=0 |
n |
0 |
4.01 |
Produces spines, thorns or burrs |
y=1, n=0 |
n |
0 |
4.02 |
Allelopathic |
y=1, n=0 |
||
4.03 |
Parasitic |
y=1, n=0 |
n |
0 |
4.04 |
Unpalatable to grazing animals |
y=1, n=-1 |
n |
-1 |
4.05 |
Toxic to animals |
y=1, n=0 |
n |
0 |
4.06 |
Host for recognized pests and pathogens |
y=1, n=0 |
n |
0 |
4.07 |
Causes allergies or is otherwise toxic to humans |
y=1, n=0 |
n |
0 |
4.08 |
Creates a fire hazard in natural ecosystems |
y=1, n=0 |
n |
0 |
4.09 |
Is a shade tolerant plant at some stage of its life cycle |
y=1, n=0 |
y |
1 |
4.10 |
Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island) |
y=1, n=0 |
y |
1 |
4.11 |
Climbing or smothering growth habit |
y=1, n=0 |
n |
0 |
4.12 |
Forms dense thickets |
y=1, n=0 |
||
5.01 |
Aquatic |
y=5, n=0 |
n |
0 |
5.02 |
Grass |
y=1, n=0 |
n |
0 |
5.03 |
Nitrogen fixing woody plant |
y=1, n=0 |
n |
0 |
5.04 |
Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers) |
y=1, n=0 |
n |
0 |
6.01 |
Evidence of substantial reproductive failure in native habitat |
y=1, n=0 |
n |
0 |
6.02 |
Produces viable seed. |
y=1, n=-1 |
y |
1 |
6.03 |
Hybridizes naturally |
y=1, n=-1 |
y |
1 |
6.04 |
Self-compatible or apomictic |
y=1, n=-1 |
y |
1 |
6.05 |
Requires specialist pollinators |
y=-1, n=0 |
n |
0 |
6.06 |
Reproduction by vegetative fragmentation |
y=1, n=-1 |
||
6.07 |
Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1 |
See left |
4 |
-1 |
7.01 |
Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas) |
y=1, n=-1 |
n |
-1 |
7.02 |
Propagules dispersed intentionally by people |
y=1, n=-1 |
y |
1 |
7.03 |
Propagules likely to disperse as a produce contaminant |
y=1, n=-1 |
n |
-1 |
7.04 |
Propagules adapted to wind dispersal |
y=1, n=-1 |
n |
-1 |
7.05 |
Propagules water dispersed |
y=1, n=-1 |
y |
1 |
7.06 |
Propagules bird dispersed |
y=1, n=-1 |
y |
1 |
7.07 |
Propagules dispersed by other animals (externally) |
y=1, n=-1 |
n |
-1 |
7.08 |
Propagules survive passage through the gut |
y=1, n=-1 |
y |
1 |
8.01 |
Prolific seed production (>1000/m2) |
y=1, n=-1 |
y |
1 |
8.02 |
Evidence that a persistent propagule bank is formed (>1 yr) |
y=1, n=-1 |
n |
-1 |
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 |
1 |
8.05 |
Effective natural enemies present locally (e.g. introduced biocontrol agents) |
y=-1, n=1 |
||
Total score: |
10 |
Supporting data:
Notes |
Source |
|
1.01 |
(1)" 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." [no evidence that cultivation has modified species] |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.40. |
1.02 |
||
1.03 |
||
2.01 |
(1)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 Sudan Tanzania Zanzibar Zimbabwe Caribbean Haiti Puerto Rico North America Mexico [USA] Florida Hawaii South America Brazil Oceania [Australia] Australian Northern Territory Queensland |
(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. |
2.02 |
||
2.03 |
(1)"Its altitudinal range is 0-1500 m" (2)Commonly known as 'neem', A. indica can be grown under a range of climatic and soil conditions. |
(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
2.04 |
(1)distribution: India (native); South East Asia, East Africa, Caribbean Islands, Queensland, California, South Florida (introduced) |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.41. |
2.05 |
(1)Introduced to various countries in South East Asia, East Africa, Caribbean Islands, Queensland of Australia, California & South Florida of USA. |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.41. |
3.01 |
(1)" 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)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.40. |
3.02 |
(1)"this study only found limited evidence that neem is a major weed overseas. While it has escaped cultivation and become naturalised in a number of countries, its impact is poorly documented." [also see 3.04] (2)In addition, Neem, Azadirachta indica A. Juss. (MELIACEAE) (syn. Melia azadirachta L.), until recently promoted by the QDPI and planted as an amenity species at several locations in the dry tropics of Queensland, has established as a weed species on the Gilbert River system and about Normanton in the Gulf Plains bioregion. Of these species C. velutina and A. indica are listed by Csurhes and Edwards (1998) and noted as having a weed history overseas. (3)It is known to be invasive in Ghana..., spreads from rural plantations into undisturbed bush in northern Australia...and is also listed as a potential environmental weed in Australia. |
(1)Csurhes, C. 2008. Pest plant risk assessment: Neem tree Azadirachta indica. Department of Primary Industries and Fisheries, Brisbane Qld. (2)Wilson, G.W., B. M. Waterhouse and G. L. Werren. 2004. The use of exotic species in dry tropics forestry: assessments, potential conflicts of interests and the application of The Precautionary Principle. Prospects for high-value hardwood timber plantations in the 'dry' tropics of northern Australia, Mareeba, 19th – 21st October 2004. (3)Schroth, G., Gustavo A. B. Da Fonseca, Celia A. Harvey, Claude Gascon, Heraldo L. Lasconcelos, Anne-Marie N. Izac. 2004. Agroforestry and biodiversity conservation in tropical landscapes. Island Press, Washington, D.C. |
3.03 |
(1)listed as an agricultural weed in Canada [no information on impacts] |
(1)http://www.hear.org/gcw/species/azadirachta_indica/ [Accessed 11 Mar 2009] |
3.04 |
(1)Weed status: In recent years neem has emerged as a serious weed in the dry tropics of northern Australia. In a recent article published by the Weeds CRC, ‘Neem - miracle tree or ecological menace?’, there is a call for immediate action to prevent further spread of this tree. Neem has become a prolific weed along the Gilbert River in the Gulf of Carpentaria, along the Victoria River in the Northern Territory, along the Ord River in Western Australia, and around Broome. Its seeds are spread down watercourses, and by fruit-eating birds such as bowerbirds. According to CSIRO scientist Tony Grice: “There is a need for immediate policy measures and actions to remove the risk of further infestations developing, to document the scale of current infestations, and put in place strategies for containment or, where possible, eradication.” (2)There is some evidence that neem extracts can affect certain aquatic life including fish and tadpoles (NRC 1992) and some speculation that chemical compounds leached out of neem leaf litter might affect aquatic wildlife. There is also concern over the plant’s potential impact on native insect populations (Lonsdale 1999, pers. comm.). [no information on negative impacts at this point, but sufficient evidence to answer "Yes" to 3.02] |
(1)Low, T. and C. Booth. 2007. The Weedy Truth About Biofuels. The Invasive Species Council, Melbourne. (2)Csurhes, C. 2008. Pest plant risk assessment: Neem tree Azadirachta indica. Department of Primary Industries and Fisheries, Brisbane Qld. |
3.05 |
(1)no evidence |
(1)http://www.hear.org/gcw/scientificnames/scinamea.htm [Accessed 11 Mar 2009] |
4.01 |
(1)no description of theses traits |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.11. |
4.02 |
(1)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. |
(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 |
4.03 |
(1)evergreen tree |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.10. |
4.04 |
(1)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)In Nigeria, damage to A. indica by several species of mammals has been reported. Browsing by domestic goats, Capra hircus, damages plantings. The red flanked duiker, Cephalophus rufilatus, occasionally causes slight bark damage. The Nigerian hare, Lepus crawshayi, is suspected of eating the tops of seedlings in forest nurseries |
(1)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. (2)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
4.05 |
(1)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. |
(1)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 |
4.06 |
(1)Pests recorded: |
(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. |
4.07 |
(1)Neem compounds have been judged to be relatively non-toxic to mammals. |
(1)http://www.winrock.org/forestry/factpub/Factsh/NeemUses.htm |
4.08 |
(1)no evidence of increased fire hazards from this tree |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
4.09 |
(1)"A. indica is a light demander but it also tolerates fairly heavy shade during its early development. " |
(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. |
4.10 |
(1)"Mohan et al observed that née grew best on clay soil"; "The neem tree was found superior in enriched sandy and loamy soil with calcium and in increasing soil pH" (2)The tree grows on a variety of soils, clayey or sandy, saline or alkaline. It does particularly well, however, on black cotton soils and deep, well drained soils with good subsoil water. Unlike most other multipurpose tree species, A. indica thrives on dry, stony, shallow soils and even on soils with hard calcareous or clay pans at a shallow depth...A. indica can grow on soils with a wide pH range. The optimum growth is at pH 6.2 to 7, but it can also grow well down to pH 5 and survive in soils between pH 3 and 9 |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.43. (2)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
4.11 |
(1)tree |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.10. |
4.12 |
(1)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"] |
(1)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 |
5.01 |
(1)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. |
(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. |
5.02 |
(1)Meliaceae |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
5.03 |
(1)no evidence [Meliaceae] |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
5.04 |
(1)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. |
(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. |
6.01 |
(1)no evidence |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
6.02 |
(1)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." |
(1)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. |
6.03 |
(1)"In some areas, hybridization has occurred between A. indica and A. siamensis" |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.17. |
6.04 |
(1)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. |
(1)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. |
6.05 |
(1)" The small, white, bisexual flowers are born in axillary clusters. They have honeylike scent and attract many bees." |
(1)National Research Council (1992) Neem: A Tree For Solving Global Problems. National Acadey Press, Washington D.C. 141pp. P.23 |
6.06 |
(1)Ability to sucker; regenerate rapidly; coppice; pollard [ability to sucker, but no indication of how far from source tree] |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
6.07 |
(1)" 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) (2)The tree starts fruiting at an age of about 5 years, but economic yield of fruit is obtained at an age of 10-12 years. |
(1)National Research Council (1992) Neem: A Tree For Solving Global Problems. National Acadey Press, Washington D.C. 141pp. P.25 (2)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
7.01 |
(1)Fruits with no means of external attachment |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
7.02 |
(1)"It is cultivated as well as naturalized" |
(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. |
7.03 |
(1)The fruit of A. indica is a drupe, 12-18 mm long, ovoid-oblong, yellowish-green, smooth dark-yellow when ripe. The walls break down from the mucilaginous mesocarp. The endocarp is thin, cartilaginous, with inter-cellular space between the epicarp and endocarp. The seeds are 1-2 reticulate. The outer seed coat has thick walled epidermis and three layers of loosely arranged cells, with the cell of the inner integument elongating tangentially to form the inner seed coat [no evidence that fairly large fruits/seeds are contaminants of produce] |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
7.04 |
(1)The fruit of A. indica is a drupe, 12-18 mm long, ovoid-oblong, yellowish-green, smooth dark-yellow when ripe. The walls break down from the mucilaginous mesocarp. The endocarp is thin, cartilaginous, with inter-cellular space between the epicarp and endocarp. The seeds are 1-2 reticulate. The outer seed coat has thick walled epidermis and three layers of loosely arranged cells, with the cell of the inner integument elongating tangentially to form the inner seed coat [no evidence that fairly large fruits/seeds are contaminants of produce] |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
7.05 |
(1)Neem has become a prolific weed along the Gilbert River in the Gulf of Carpentaria, along the Victoria River in the Northern Territory, along the Ord River in Western Australia, and around Broome. Its seeds are spread down watercourses, and by fruit-eating birds such as bowerbirds. |
(1)Low, T. and C. Booth. 2007. The Weedy Truth About Biofuels. The Invasive Species Council, Melbourne. |
7.06 |
(1)Primarily dispersed by bats (2)"Occasionally, some fruits are swallowed by birds for their sweet pulp and the seeds are passed out of the body, undigested, because of the hard endocarp" |
(1)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. |
7.07 |
(1)Fruits with no means of external attachment |
(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
7.08 |
(1)"Occasionally, some fruits are swallowed by birds for their sweet pulp and the seeds are passed out of the body, undigested, because of the hard endocarp" (2) It has been recorded that germination is enhanced by passage through the guts of baboons |
(1)Puri, H.S. (1999) Neem The divine tree Azadirachta indica. Harwood Academic Publishers. 182 pp. p.16. (2)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
8.01 |
(1)p.9 "A mature tree produces 30-50 kg seed every year." 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] (2)There are 3300-4500 seeds per kilogram, and on average a medium-sized tree produces 37-55 kg of fruit |
(1)Read M.D. & French, J.H. Eds. (1993) Genetic Improvement of Neem: Strategy 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. (2)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
8.02 |
(1)p.89 "Neem is propagated primarily through seed, which has a short viability of 3-4 weeks" (2)A. indica is propagated primarily through seed. The seeds are recalcitrant and are shed at relatively high moisture content, hence are prone to dehydration and chilling injuries (Mishra, 1995). They have a short viability of 3-4 weeks. Seeds stored at 4°C show a high germination percentage. To maintain viability of the seeds, the drupes must be cleaned properly by depulping, either manually or mechanically under a stream of water to provide stones. Drying stones in shade is the most appropriate method although drying in the sun, an oven or vacuum provides acceptable results more quickly. Stones give better germination rates than seeds...The short viability of the seed and different ripening times in various localities is a serious problem and poses logistic difficulties for the introduction of this species to new locations. |
(1)Read M.D. & French, J.H. Eds. (1993) Genetic Improvement of Neem: Strategy 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. (2)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
8.03 |
Unknown |
|
8.04 |
(1)"The roots penetrate 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" (2) It regenerates naturally and is propagated mainly through seed. It also regenerates well by coppicing and pollarding, and can produce root suckers, especially in dry localities |
(1)National Research Council (1992) Neem: A Tree For Solving Global Problems. National Acadey Press, Washington D.C. 141pp. P.23 (2)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. |
8.05 |
Unknown |
Need more info? Have questions? Comments? Information to contribute? Contact PIER!
[ Return to PIER homepage ] [Risk assessment page]
This page created 7 December 2009