Disease incidence and varietal reactions of 51 melon landraces collected from Lake Van Basin, one of the secondary gene center of melon, to the physiologic races (the race I and the race 2) of Fusarium oxysporum f. sp. melonis (F.o.m.) were determined by artificial inoculations. The study was carried out in a growth chamber and pathogen isolates of the races were incubated in a medium containing corn meal and sand, and then this inoculation source was mixed with a seedling growth medium at the rate of 5% (final density: 10(6) conidia ml(-1)). Melon seedlings were evaluated with a 0-3 scale four weeks after the seed sowing in order to detect disease incidence. Disease incidence in melon genotypes against the race 1 and race 2 of F.o.m. ranged between 23% and 100% and between 7% and 100%, respectively. Moreover, F.o.m. races 1 and 2 did not form any disease incidence in four and one melon genotypes, respectively. One of the melon genotypes, 65 ERC 03, was found to be resistant to both races.