Giant leucaena (Leucaena leucocephala (Lam.) de Wit ssp. glabrata)
| The basics | Giant leucaena is a very fast-growing fodder and multi-purpose species, native to Mesoamerica but grown widely throughout the tropics and subtropics. The common and subspecific names distinguish it from L. leucocephala ssp. leucocephala (“common leucaena”), which is weedier and less useful. |
| Climatic requirements | Tropics and subtropics (> 600 mm mean annual precipitation) [1, 2]. Vigorous up to at least 600 m a.s.l. [1, 2]. Used as coffee shade at elevations up to 1500 m a.s.l. [3] |
| Most salient traits versus positive implications | High-protein, highly livestock-palatable foliage [1]; coppicing; fast growth; drought resistant [1]; N-fixing ⟹ excellence as fodder species Deep roots [1, 3], N-fixation ⟹ suitability for perennial-crop shade, especially coffee [3, 4, 5] Fast growth; coppicing; high calorific value [2] ⟹ useful bioenergy crop, including fuelwood Deep roots; N-fixing ⟹ useful in land restoration and soil stabilization |
| Most salient traits versus negative implications | Foliage is high in livestock-toxic mimosine, which breaks down in the gut to the also-toxic DHP [1, 6, 7] ⟹ risk of livestock poisoning Self-pollinating; precocious; abundant seed production; orthodox seed; fast growth ⟹ high invasiveness [8] Susceptible to attack by the skilled insect Heteropsylla cubana [1, 6, 9] ⟹ risk of crop failure Acidic-soil-intolerant [1, 10] ⟹ unsuitability for many tropical soils, especially in wet tropics |
| Problem mitigation | Psyllid attack: In wet tropics, use psyllid-resistant cultivars [1, 6, 9, 11] Mimosine and DHP: In brief, cattle unused to leucaena should be introduced to it gradually and not be allowed to gorge (this avoids acute mimosine poisoning). The rumen bacteria that break down mimosine and DHP can be boosted by treating 10% of the herd with a rumen inoculum. See reliable guides such as references [1] and [9]. In cut-and-carry systems, simple techniques such as extended soaking in water can be used to remove mimosine from foliage and fruits [12]. Invasiveness: The leucaena code of practice adopted in Australia specifies management measures to reduce the risk of invasiveness (see Appendix 1 of reference [1]). Additionally, growers should avoid inadvertent use of the weedier subspecies L. leucocephala ssp. leucocephala. |
| Other must-knows | – Leucaena seed must be scarified before sowing. Soaking in hot water (90C) for two minutes is an effective scarification method [13]. Without scarification, germination percentages are low. – To ensure effective nitrogen fixation, seed must be inoculated with a suitable strain of Rhizobium such as CH3050 or TAL1145. See reference [1] for inoculation techniques. Inoculation is simple and requires no special equipment. – Many different cultivars of giant leucaena are available – probably more than for any other non-fruit agroforestry species. Cultivars differ in their suitability for different uses and environments. References [1], [6], [6], and [11] list and describe many cultivars. Stumps can be produced from bare-root seedlings of leucaena [13]. Stumps are cheaper and easier to transport and plant than containerized stock [14]. Direct seeding of scarified seed is also effective, if the planting site is well prepared [1]. |
| References | [1] Shelton M et al. 2021. Leucaena: The productive and sustainable forage legume. https://era.dpi.qld.gov.au/id/eprint/9425/1/leucaena-productive-sustainable-forage-legume-1.pdf. [2] NAS (National Academy of Sciences). 1980. Firewood crops. Shrub and tree species for energy production. https://nap.nationalacademies.org/read/21317/chapter/1. [3] Snoek D. 1996. Beneficial effects of Leucaena-Rhizobium association on coffee in Burundi . Plantations, Recherche, Développement. 3(6): pp. 408-417. https://agritrop.cirad.fr/388375/. [4] Kuit M et al. 2004. Coffee handbook (Manual for Arabica production) [Vietnam]. https://bootcoffee.com. [5] Enveritas. 2023. Establishing carbon footprint baselines for robusta coffee production in two origins in Southeast Asia. https://www.enveritas.org. [6] Bageel A et al. 2020. Giant leucaena (Leucaena leucocephala subsp. glabrata): a versatile tree-legume for sustainable agroforestry. Agroforestry Systems (2020) 94:251–268. [7] Future Beef (Australia). 2022. Leucaena inoculum for cattle. https://futurebeef.com.au/resources/leucaena-inoculum/. [8] IUCN. 2025 (access date). GSID (Global Invasive Species Database). https://www.iucngisd.org/gisd/speciesname/Leucaena+leucocephala. [9] Brewbaker JL. 2016. Breeding Leucaena: tropical multipurpose leguminous tree. In Janick J (Ed.). Plant Breeding Reviews Vol. 40. John Wiley. [10] Evans DO and Szott LT (Eds.). 1995. Nitrogen fixing trees of acid soils. Nitrogen Fixing Tree Association (NFTA) Research Reports. Special Issue 1995. [11] Dalzell S. 2019. Leucaena cultivars – current releases and future opportunities. Tropical Grasslands-Forrajes Tropicales (2019) 7(2):56–64. [12] Soedarjo M and Borthakur D. 1996. Simple procedures to remove mimosine from young leaves, pods and seeds of Leucaena leucocephala used as food. Int J Food Sci Technol 31:97–103. [13] Dhanda S and Chauhan BS. 2022. Seed germination ecology of leucaena (Leucaena leucocephala) as influenced by various environmental parameters. Weed Science 70 (3). https://doi.org/10.1017/wsc.2022.18. [14] Evans J. 1992. Plantation forestry in the tropics (2nd edition). Clarendon Press. |