more Images
Lead tree
Scientific name:
Leucaena leucocephala/L. Glauca/L.latisiliqua
Order/Family:
Fabaceae
Local names:
Common names: Luo: Lusina; Swahili: Lusina.
Introduction
Lead tree
© Bo Tengnas
General Distribution:
It was widely introduced in the tropics over the last 100 years, reaching Africa in 1950. It is naturalized and to some extent invasive in some parts of Kenya with moist ground and warm climate.


General Information about the Tree:
The species exhibits great variation. The chemical mimosine in the leaves can cause hair loss, infertility and stomach problems in livestock, especially non-ruminants like donkeys. Livestock feed should not therefore contain more than 20% of Leucaena.


Biophysical Limits:
It grows well at altitudes of 0-1,600m, in full sunlight and in well drained neutral or calcareous soil. It does not tolerate acidic soils and needs more than 600mm rainfall. It does well in agro-ecological zones II-V.
back to Index
Propagation and Tree Management
It may be propagated by use of seedlings and direct sowing at site. Is very fast growing on suitable sites; pollarding, lopping and coppicing may be employed. High plant densities are recommended for solid fodder. Fodder yields range from 40 to 80 t/ha when moisture is not limiting.


Products:
  • Food: Pods, seeds and leaf tips have been used as food, although mimosine toxicity makes this practice risky.
  • Fodder: is one of the high quality and most palatable fodder trees of the tropics being equaled to the "alfalfa of the tropics".
  • Apiculture: is in bloom almost throughout the year, providing constant forage to honey bees.
  • Fuel: is an excellent firewood species
  • Other products: poles, medicine (roots), mulch, tannin and dye


Services:
  • Erosion control: An aggressive taproot system helps in reducing the run-off.
  • Shade or shelter: is often is used as a shade tree for cocoa, coffee and tea; it generally acts as a shelterbelt, providing shade and wind protection for a variety of crops, especially during early growth.
  • Reclamation: L. leucocephala thrives on steep slopes and in marginal areas with extended dry seasons, making it a prime candidate for restoring forest cover, watersheds and grasslands.
  • Nitrogen fixing: It has high nitrogen-fixing potential due to its abundant root nodulation.
  • Soil improver: it is also used for the production of green manure in alley cropping
  • Ornamental: it is suitable as an ornamental and roadside landscaping tree species.
  • Boundary or barrier or support: it is used as a live fence, firebreak and live support for vines such as pepper, coffee and cocoa, vanilla, yam and passion fruit.
  • Intercropping: is one of the most widely used species in alley cropping, where it is planted in hedges along contours with crops in between.
back to Index
Pests and Diseases
A psyllid insect pest, Heteropsylla cubana, causes defoliation. In Kenya, the psyllid defoliates the leucaena, resulting in severely reduced production of fodder as well as wood, but without killing the leucaena but it has caused serious defoliation and mortality in eastern Africa. A Caribbean parasitoid, Psyllaephagus, shows specificity and excellent appetite for H. cubana and hence offers possibilities for biological control. Some varieties of lusina are susceptible to gummosis, most likely caused by Fusarium semitectum. Ganoderma lucidum is said to cause root rot in arid and semi-arid regions and Leaf-spot fungus can cause defoliation under wet conditions. Wild animals avidly consume seedlings.
back to Index
Information Source Links
back to Index
Lead tree
© Bo Tengnas
Mulch
Plant material such as straw, leaves, crop residues, green manure crops, saw-dust etc. that is spread upon the surface of the soil. A mulch cover helps protect the soil from erosion and evaporation, nourishes soil life, increases soil organic matter content and provides nutrients to the crop.
Fungi
Occurring worldwide, most fungi are largely invisible to the naked eye, living for the most part in soil, dead matter, and as symbionts of plants, animals, or other fungi. They perform an essential role in all ecosystems in decomposing organic matter and are indispensable in nutrient cycling and exchange. Some fungi become noticeable when fruiting, either as mushrooms or molds.

Fungi are responsible for a range of serious plant diseases such as blight, grey mould, bunts, powdery mildew, and downy mildew. Crops of all kinds often suffer heavy losses.

Fungal plant diseases are usually managed with applications of chemical fungicides or heavy metals. In some cases, conventional breeding has provided fungus resistantcultivars.

Besides combatting yield losses, preventing fungal infection keeps crops free of toxic compounds produced by some pathogenic fungi. These compounds, often referred to as mycotoxins, can affect affect the immune system and disrupt hormone balances. Some mycotoxins are carcinogenic.
Green manure
A crop grown before or between the main crop rows, cut before maturation and subsequently ploughed in or used as mulch. It provides nutrients to the main crop through decomposition and helps to build up humus in the soil.