Economic Injury Levels of Empoasca dolichi Paoli on Groundnuts (Arachis hypogaea L.) in Zaria Area of Northern Nigeria
EGWURUBE, E.A., OGUNLANA, M.O., DIKE, M.C and ONU, I.
ABSTRACT: Population of Empoasca dolichi Paoli were studied during the rainy seasons of 2000 and 2001 respectively to determine their economic injury levels (EIL) on groundnut in Zaria area, northern Nigeria. Groundnut (Variety RRB) was artificially infested with different population levels of E. dolichi at three different stages of plant growth. The growth stages of the plant at which infestations were made were R1 (groundnut beginning bloom), R4 (Full pod development)and R7 (groundnut beginning maturity). The results showed consistent decreasing groundnut yield with increasing population of E. dolichi. Based on mean groundnut market values and insect control costs for 2000 and 2001, economic-injury levels determined were 1,6 and 13 leafhoppers/plant for groundnut growth stages R1, R4 and R7 respectively