Conducting ethanobotanical surveys: an example from Ghana on plants used for the protection of stored cereals and pulses (NRI Bulletin 77)

A survey was undertaken in the Ashanti Region of Ghana to assess the use of plant materials with insecticidal and repellent properties on local farms. Emphasis was placed on plant materials used to protect stores containing cereals and pulses. A total of 27 plant species were recorded as having protective qualities against storage pests of cereals and pulses. The species Chromolaena odorata (L.) [siam weed], Azadirachta indica A. Juss [neem] and Capsicum annuum L. [chilli pepper] were the most commonly used to protect stored food. In addition to plants used to protect stored products, bio-activity against insect pests was reported in approximately 95 plant species. The most frequently mentioned plant species were Bambusa vulgaris Schrad. [bamboo], Citrus spp. [lime, lemon and orange], Datura innoxia Mill., Manihot esculenta Crantz [cassava] and Piper umbellatum L. The survey found that 26% of the farmers interviewed used botanicals in some form for stored product protection; however, only a small percentage (7%) relied on them exclusively to protect their harvest from storage pests. Smoking of maize stores was the most common method of control in most districts (28%), with the exception of the major maize-growing districts (Ejura and Mampong), where the majority of farmers used conventional insecticides for the control of stored product pests