Interactions between Heterodera rostochiensis Woll. and Verticillium dahliae Kelb. on potatoes and the effect of CCC on both

SUMMARY H. rostochiensis (British pathotype A) increased the severity of the disease caused by Verticillium dahliae in potato plants grown in pots when there were more than ten eggs/g of soil and both pathogens parasitized the root system together. The growth‐suppressing chemical CCC, which severely stunted plants, prevented the disease and decreased H. rostochiensis reproduction. An estimate of foliage symptoms measured the effects of the disease more precisely than did tuber yields.