Potential of crop diversity for pest management II. Mechanisms of influence.
ABSTRACT: The second of a two-part review paper, this attempts to categorize the various mechanisms that have been suggested to be responsible for reductions in the abundance of pests due to diversification of agro-ecosysterns. Examples from work by the author on pest abundance in crop associations between cowpea and sorghum at Zaria and between carrots and onions at Cambridge are also included. It is suggested that existing knowledge on crop diversity could be gainfully exploited to improve polycultural systems in labour- intensive agriculture.