Onderzoekingen over kurkwortel van tomaat en over de kurkwortelschimmel

Termohlen proved that corky root was caused by a fungus, which was readily isolated and cultivated. The fungus did not sporulate but several isolates made sclerotia on agar. Its features on nutrient medium were described. The fungus had not been named. Isolates varied greatly in pathogenicity. The pathogen remained in the soil as myceliurn in root debris and possibly also as sclerotia.Besides the tomato several other Solanaceae were susceptible to corky root. From Physochlaena orientalis and cucumber the pathogen could be isolated; these plants, however, did not show any symptoms and were thus carriers. Rotation experiments with cucumber and some other crops alternating with tomato had but little effect on the inoculum potential of the soilControl was by steaming the soil or disinfecting it with chloropicrin. DD had no effect.All cultivated varieties of tomato so far tested were susceptible. Lycopersicum glandulosum, L. peruvianum and L. hirsutum were highly resistant. Crosses to obtain resistant tomato varieties were made. The first filial generation of the crossing L. esculentum with L . hirsutum was resistant and suitable as a root stock for the tomato but it was susceptible to eelworm infestation