Pests and Diseases Associated with Yam Bean (Pachyrhizus erosus) Cultivation at Farmers’ Levels in the Central Region of Benin

Roots and tubers are one of the most important crops that provide food security in West Africa. Thus, Pachyrhisus erosus with its various potentials, is planned to be introduced in Benin to improve the nutritional quality of the population. Prior to that, this study aimed at assessing pests and disease of P. erosus in the agroecological conditions in the central parts of Benin. Conducted at experimental field in Savè during two consecutive years, experiments were laid in a completely randomized block design with 4 replications and three treatments including EC 533 and EC Kew cultivars of P. erosus and cowpea variety named Kpodji-Guèguè. Results showed that the major pests collected from P. erosus namely Ootheca mutabilis, Medythia quaterna, Piezotrachelus varium, Megalurothrips sjostedti and Brevipalpus phoenis were not so far reported in it. Compared to cowpea, pest’s infestation and their damages were lower on P. erosus. Infestation severity on leaves and the percentage of perforated green pods ranged from 0.7% to 3% against 0.8% to 88.9% and from 12.5% to 16% against 57.2% to 64% respectively on P. erosus and cowpea. Cercospora disease caused by Cercospora canescens and yam bean leaf blight caused by an unknown fungus were observed. Cercospora disease affected cowpea and P. erosus while yam bean leaf blight affected only P. erosus. This study provides additional data on pests and diseases associated with P. erosus worldwide and alerts farmers regarding their management.

Observations on Insect Infestation and Damage in Cowpea (Vigna Unguiculata) Intercropped With Tomato (Lycopersicon Esculentum) in a Rain Forest Area of Nigeria

SUMMARYInsect infestation and damage in cowpea (Vigna unguiculala), planted sole or intercropped with tomato (Lycopersicon esculentum) was monitored in 1987 and 1988 in Akure, Nigeria. Infestation of cowpea byEmpoasca dolichiwas significantly reduced by intercropping with tomato in both years, except in the early season of 1988. Infestation of cowpea byOotheca mutabilis, Aphis craccivora, Megalurothrips sjosledti and Maruca testulaliswas not affected by intercropping with tomato in either year. Damage by pod-sucking bugs and Heliothis armigera was significantly higher in sole cowpea than in cowpea intercropped with tomato, in both years. Sole cowpea had a significantly lower seed yield than cowpea intercropped with tomato.Observaciones en cuanto a la infestación de insectos y daños en el caupí(Vigna unguiculata)sembrado en forma simultánea con tomate(Lycopersicon esculentum)en una zona de bosque tropical en Nigeria

Effect of Weeds on Pre-flowering Insect Infestation and Seed Yield of Cowpea (Vigna unguiculata) in a Rainforest Area of Nigeria

SUMMARYPre-flowering insect infestation of cowpea, Vigna unguiculata, was monitored in weedy and weed-free plots in 1986 and 1987 in Akure, Nigeria. Weediness generally reduced infestations of both the leafhopper, Empoasca dolichi, and the flea beatle, Ootheca mutabilis. However, seed yield was reduced in the weedy plots despite heavier pre-flowering insect populations in the plots kept weed-free.

Ootheca mutabilis. [Distribution map].

A new distribution map is provided for Ootheca mutabilis (Sahlberg) [Coleoptera: Chrysomelidae, Galerucinae] Brown leaf beetle, cowpea leaf beetle. Attacks various Leguminosae including Vigna unguiculata, Cajanus cajan, Canavalia ensiformis, soyabean & groundnut, vector of bean southern mosaic virus and cowpea mottle virus. Information is given on the geographical distribution in AFRICA, Angola, Benin, Cameroon, Ghana, Guinea, Kenya, Liberia, Malawi, Mozambique, Nigeria, Rwanda, Senegal, Sierra Leone, South Africa, Sudan, Tanzania, Zaire, Zambia, Zimbabwe.