BaseInfo Subabul

The genus Leucaena is of Mexican and Central American origin. The best known species of the genus leucaena is L. Leucocephala belongs to family Mimosace originated in the midlands of southern Mexico, Guatemala and EL Salvdor. It grows in areas with annual rainfall as low as 50mm to 2500mm, but cannot tolerate water-logged and acidic soil conditions.L. Leucocephala is not new to Indian conditions. As early as 1931, it was introduced by F.R.I. However greater interest was shown by various government and non-government institutions in India . It is however a popular pulpwood species in India primarily due to its ease in establishment through seeds as well as vegetative propagation, ability to withstand repeated coppicing and fix nitrogen. However, it is susceptible to water logging conditions, acidic soils, and frost and drought conditions.

The current pulp yields in leucaena range is around 47%, basic density ranges from 0.54 – 0.61 and lignin content from 25- 27 %. The fiber length ranges from 0.85 – 1 mm.

Triploid Leucaena (that is sterile and does not produce seeds) has been developed by ICRAF, by crossing the tetraploid L. leucocephala with the diploid L. trichandra. This will be a major field of interest in our Leucaena breeding programme

Table 1. Introduced seed lots of Leucaena from ICRAF, Kenya

Botanical name Provenance Quantity (gms) Chromosome number Rainfall(mm) Altitude (m) Leucaena pallida Mackakos 114 Tetraploid 2n=104 self-incompatible 500-1000 1300-2200 Leucaena trichandra NA 240 Diploid, 2n=52

self-incompatible

700-2000 Leucaena diversifolia Muquga 105 Tetraploid, 2n=104 Self compatible 1500-3500 30-1500 Leucaena leucocephala var. K636 Mackakos 137 Tetraploid, 2n=104 Self compatible 700-1300

Leucaena esculenta Mackakos 135 Diploid, 2n=52 self-incompatible 800-1300 600-1800