Potato varieties and powdery mildew attacks

Conclusions

Our observations gave us the impression that various descendants ofPhytophthora-resistant parents that owe their resistance toSolanum demissum are very susceptible to attacks by mildew. In the greenhouses too, seedlings withPhytophthora resistance suffered most.

As far as I am aware mildew has not been noticed before in potato fields in the Netherlands. According to my observations, however, the commercial varieties can be attacked more or less when exposed to infection and it may be considered important to find parental material combiningPhytophthora resistance with that to powdery mildew.

Samenvatting

Aardappelrassen en meeldauwaantasting

Meeldauwaantasting van aardappelen werd in de kassen van het I. v. P. en S. v. P. elk jaar, doch in 1950 op het Aardappelveredelingsbedrijf in de N.O. Polder voor het eerst in het vrije veld in Nederland waargenomen. Grote verschillen in aantasting der diverse aardappelclonen werden geconstateerd. Vooral talrijke rassen metSolanum demissum in hun stamboom werden ziek, zodat bij de veredeling opPhytophthora resistentie getracht moet worden deze te combineren met onvatbaarheid tegen meeldauw.