USE OF NONTARGET ISOLATES OF THE ENTOMOPATHOGEN VERTICILLIUM-LECANII (ZIMM) VIEGAS TO CONTROL THE POTATO CYST NEMATODE, GLOBODERA-PALLIDA (STONE)

An attempt was made to control Globodera pallida using the entomopathogenic fungus Verticillium lecanii; 14 isolates, 10 of them pathogenic to insects, were tested in vitro against mature eggs of G. pallida. Infection by the 14 isolates two months after inoculation of cysts with conidia ranged from 4-63%, with eight isolates infecting 45-63% of the eggs. Observations with the scanning electron microscope revealed hyphae emerging from the inside of eggs infected by isolate # 1, which confirmed its capability to penetrate eggs. This isolate infected viable and non-viable (heat-killed) eggs to the same extent - 36% and 29%, respectively. Based on the favourable results in the laboratory, the prospects of utilizing isolates of V. lecanii against mature eggs of G. pallida under field conditions are discussed.