Potentials of plant extract for the control of two field pest of cowpea (Vigna unguiculata Walp,)

Abstract

Two field experiments were conducted at Research Farm of NAERLS/ABU Badeggi, North Central Zone in the Southern Guinea Savanna Zone of Nigeria in 2013 and 2014 to screen the insecticidal potential of three local plant products as usable bio-pesticides. The three plant products were Tephrosia vogellic, Azadiracta indica and Annona senegalensis. A synthetic insecticides- pirimophos methyl (Actellic dust) and a control treatment where neither the plant product nor the synthetic insecticide was included for comparison. The results obtained from the study showed that all the local plant treatments reduced aphid population from four weeks after planting until seven weeks when there was no appreciable reduction any more. Generally, the Ootheca species recorded across the treatments including the control is low for both years when plant products were used. In both years plot sprayed with extracts from Azadiracta produced significantly higher pod weight than plots sprayed with Tephrocia or Annona extracts. Similarly leaf extracts from Azadiracta and Tephrocia produced the highest weight of pods per plot in both years. All the treatments produced more pods per plot than that of the control treatment with neither plant products nor the synthetic insecticides.