Root Growth and Distribution Pattern in Leucaena leucocephala,Gliricidia sepium and Senna siamia in the Humid-lands of Ghana

Abstract

Horizontal and vertical distribution of roots of one year old Leucaena leucocephala,Gliricidia sepium and Senna siamea plants on field plots were studied using the skeleton(dry excavation) method. Root systems of the three species generally consisted of a strong downward growing tap root with laterals originating from the main root axis. In Leucaena and Senna, roots developed faster than shoots, and at the end of 9 weeks after sowing,mean root length shoot height ratios were 1.41 and 1.46 respectively. Total root biomass ranked in the order Senna > Gliricidia > Leucaena. The bulk(an average of about 81%) of the roots biomass of all the three species are found in the top 15 cm depth of the profile. Horizontal root spread varied from 98.2cm in Leucaena to 104.7cm in Senna.Active nodules were observed on the roots of Leucaena and Gliricidia but not Senna. The study concludes that the three species are likely to compete with agricultural crops for water and nutrients when grown together.