EFFECT OF THE ENTOMOPATHOGENIC NEMATODES, STEINERNEMA-FELTIAE AND S-CARPOCAPSAE, ON THE POTATO CYST-NEMATODE, GLOBODERA-ROSTOCHIENSIS, IN POT TRIALS

Two pot experiments, one in a glasshouse and the other in an outdoor s and plunge, were conducted to examine the influence of the entomopatho genic nematodes, Steinernema feltiae and S. carpocapsae, on the invasi on and development of the potato cyst nematode, Globodera rostochiensi s. Of a total of eight different treatments with entomopathogenic nema todes in the glasshouse trial, three reduced the invasion of G. rostoc hiensis and one reduced the numbers of new cysts that were produced co mpared with controls. In the outdoor experiment, seven of the 12 treat ments gave a reduction in invasion but none resulted in changes in the numbers of cysts found at plant senescence. In general, invasion of G . rostochiensis juveniles was reduced more effectively by S. carpocaps ae than by S. feltiae, and was greatest in the outdoor trial where lar ger inocula of entomopathogenic nematodes were used. Overall, the resu lts indicated that use of S. feltiae and S. carpocapsae is unlikely to provide a viable control strategy for G. rostochiensis.