Effect of Eco-Physiological Variability in Leucaena leucocephala Growth and Development

Abstract

The effect of eco-physiological differences in two sites on growth and development of Leucaena was assessed. A 2-factor (provenance-site) experiment in a completely randomized design with three (3) replications was set up. Pot and field experiments were used to assess growth and development of three local Leucaena provenances in two regions, Maseno ICRAF/KEFRI centre (pH 4.8) and Chepkoilel Campus farm (pH 5.0). Seeds of three local Leucaena provenances K156 (Gede), K136 (Kibwezi) and KIT2724 (Kitale) were used in this study. Lime was applied at 0 and 33.3 kg per kg of soil (6.7 ton/ha) in each pot and aluminium at 0, 100, 200 and 300 μM. Field experiment was conducted at Chepkoilel Campus farm. Lime was applied at a rate of 7ton/ha. Number of leaves per plant, plant height, root length, root collar diameter, plant dry weight, selected nutrients (N, P and Ca) and Al were assessed from potted and field grown seedlings. Data were subjected to multivariate analysis of variance. There was relatively better seedlings growth at Maseno than at University of Eldoret. The differences in environmental factors, such as higher mean temperatures (25°C) at Maseno could promote growth, resulting in higher plant height, root length and plant dry weight than at Chepkoilel Campus, which had lower mean temperature 17°C, However, although the Maseno plants were taller, they had smaller root collar diameters, especially after 90 days. The comparatively higher levels of nitrogen in the Maseno soils could also be responsible for the better growth. This was also reflected in the shoot tissues where the seedlings grown at Maseno had higher nitrogen content than those same genotypes grown at Chepkoilel Campus site. Seedlings at Maseno ICRAF/KEFRI centre had significantly (p < 0.05) better growth than at University of Eldoret. Maseno soils had higher N and less Al than at University of Eldoret.