The cultivar/variety chosen must offer good prospects for economic success with minimal use of agrochemicals.
IP guidelines must provide a list of the relative susceptibilities of the commonly grown cultivars to all important pests and diseases.
Late Blight: Highly susceptible cultivars must not be grown. The use of resistant/tolerant cultivars is the most appropriate preventive measure.
In nematode-infested fields, cultivars of high resistance to one or more of the nematode species or their dominating pathotypes must be grown.