HERBAGE YIELDS OF PIGEONPEA (CAJANUS-CAJAN) ACCESSIONS IN A HUMID TROPICAL ENVIRONMENT AS AFFECTED BY PRUNING MANAGEMENT

Twelve accessions of pigeonpea (Cajanus cajan [L.] Millsp.) were grown on an Alfisol in a humid ecozone in Nigeria in 1989. At 4 and 8 months after planting (MAP), the primary growth was cut to determine the effect of age at first pruning on stump survival and coppice regrowth, and also on total herbage yield in a 12-month pruning cycle. It was clear that a height of 3 m or more is adequate for pigeonpea to receive its first cut with only 10 % stool mortalities. Cutting the primary shoot at 8 MAP (in the dry season) ensured greater stump survival and also stimulated rapid coppice shoot regrowth, indicating the advantage of coppicing in the dry season and also at maturity. The total leaf and wood dry matter (DM) production in a 12-month cycle is greatest if the primary shoot was first cut at 8 MAP. This suggests that allowing the trees to become established is beneficial in the pruning management of pigeonpea. Accessions 11563 and 11575 have the ability to produce 7 t/ha of leaf DM from two prunings when first cut at 8 MAP, and significantly outperformed the local variety. The study revealed that pigeonpea does not coppice well and its biomass yields are much lower than that of Leucaena leucocephala.