Resistance inVicia faba toOrobanche crenata: True resistance versus hidden susceptibility

Summary Orobanche attack on twelve broad bean cultivars was measured in connection with vegetative growth by means of two pot tests with different innoculum densities. Orobanche attack appeared to be related to the growth vigour of the host. The higher the root and shoot biomass of a cultivar, the higher the number and the more advanced the development of the tubercles was, independent of innoculum density. Therefore, in spite of the observed variation for Orobanche attack, the tested cultivars were considered to have the same level of susceptibility, however with exception of BPL 2210. This cultivar showed a lower attack than was expected of its growth vigour.Hollandseweg 2, 6706 KP Wageningen, the Netherlands.