Evaluation of production systems, traditional knowledge of pigeon pea (Cajanus cajan) and risks of extinction of pigeon pea, Jack bean (Canavalia ensiformis) and lubia bean (Lablab purpureus) in some parts of southwest Nigeria

Abstract

Indigenous agricultural knowledge is an important part of the process of making agriculture sustainable. Therefore, the aim of the present study was to i) determine the techniques of pigeon pea production at farmers’ level, ii) investigate the level of extinction of pigeon pea, Jack bean and lubia bean species, ii) assess the distribution and potential of the three minor crops in the study areas. One hundred and fifty respondents were investigated using a structured questionnaire. Direct observation, field visit and focus group discussion were carried out. The survey was conducted in Osun and Oyo States from October to December 2017. Producers mainly grow pigeon pea for its grains for home consumption. Pigeon pea’s leaves were used for medicinal resolutions to treat primarily malaria and fever. Farmers used pigeon pea for soil fertility and to prevent erosion. There is fear that Jack bean and lubia bean species disappear with time, though farmers abandoned Jack bean for a good reason - it becomes poisonous after two years of cultivation, which always leads to death. Conservation strategies can be put in place to avoid the losses of these species for their genetic resources. This study contributes to raise awareness on the risks of losing Jack bean and lubia bean through extinction. In addition, further study needs to be carried out to found out the chemical compound responsible for poisonous seeds of Jack bean after the first harvest.