Effect of coexistence of Penicillium frequentans (westling) with Globodera rostochiensis (Woll.) behrens on potato

The aim of two‐year‐long pot experiments was to investigate the influence of P. frequentans on the growth of over‐ground parts, the intensity of assimilation and transpiration of plants, as well as ths influence on the yield of potato bulbs. It was determined how the above fungus influenced the populaüon of G rostochiensis, the influence being characterized by the density change of cysts, eggs, and larvae in the soil. Experiments in vitro allowed to determine the wholesomeness of cysts, eggs, and larvae (J2) that were in direct contact with the mycelium ofP. frequentans.

It was stated that presence of P. frequentans intensified the development of plants and relevantly stimulated their growth, especially in the initial vegetation phase, as compared with the remaining combinations (Fig. 1). Positive effect of P. frequentans on the growth of potato yield was proved, in comparison with the control, and by co‐occurrence of the fungus with G. rostochiensis, also in comparison to the combination with nematodes only (Fig. 2).

Pot experiments confirmed the antagonistic effect of P. frequentans on the population of G. rostochiensis. Presence of P. frequentans in the ground caused namely a relevant diminution of density of cysts, eggs and larvae (Tab. II), as well as morphological changes by females, which was connected with size reduction of the cysts (Tab. III). Experiments in vitro confirmed the destructive effect of P. frequentans on the cysts of G. rostochiensis (Tab. IV).