The most important losses caused by root nematodes to the potato crop in the State of Silo Paulo and other parts of Brazil are due to the species Meloidogyne incognita (Kofoide & White, 1919) Chitwood, 1949 and Pralylenchus steineri Lordello, Zamith & Boock, 1954. The former is quite widespread and measures aiming at its control were studied under field conditions. The present paper reports the results on the influence of fertilizer and soil fumigation with ethilene dibromide at 10%, cither separately or combined, on the nematode infestation of the potato yield. The results of the tests showed that the fertilizer application had no influence on the nematode infestation of the potato tubers. Fumigation with ethilene dibromide, when applied in holes 20x20 cm apart eight or more days before planting, reduced the nematode infestation of the crop. In addition, there was a satisfactory increase in yield specially when the fumigant was applied twice a year to the same plots, that is, once for the dry season planting (March to August) and another for the rainy season crop (September to February).