Utilization potentials of lablab (Lablab purpureus (L.) Sweet) and the constraints of field pests and diseases in Nigeria

Abstract

In the last one decade and half, lablab was evaluated for its crop-livestock production potentials in Samaru, Kano and Benin City in both the savanna and humid forest zones of Nigeria. Very early, early and intermediate accessions were identified that may be suitable for dry savanna and late growing season of the humid forest while late, very late and extremely late accessions were identified for moist savanna and humid forest. Vegetable-type, grain-type and dual-purpose lablab were identified. Lablab grain ranged from 600-2400 kg ha^-1 with an average protein concentration of 25.3%. Huge litter of leaves and stems was recorded at the end of production period which extended far into the dry season. Short fallow of one year supported maize-cowpea intercrop with component maize having 13.7% grain yields over that of natural fallow. Following a 2-year lablab fallow, subsequent maize yield was 72.7% higher than that from natural fallow. Lablab had an average of 2600 kg ha^-1 of biomass and an average of 64.1 kg N ha^-1, meaning that lablab has high potential for green manure and soil improvement. Of six herbaceous legumes, lablab was among those that had the highest soil cover. Fresh biomass of 3200 kg ha^-1 was achieved at eight weeks after planting. Various insect pests, fungal diseases and parasitic plant including Ootheca mutabilis (Sahlb), Podagrica uniforma (Jac.), Nematocerus acerbus (Faust), Anoplocnemis curvipes (F.), Helicoverpa armigera (Hbn), aphids, Colletotrichum sp., Curvularia sp. and Cassytha filiformis (Linn.) were found on lablab plants, causing damage to the crop.

Key words: lablab, fodder, grain yield, pest, disease