Antagonistic Interaction of Heterodera schachtii Schmidt and Fusarium oxysporum (Woll.) on Sugarbeets.

In a field experiment, nematicides controlled the disease of sugarbeets caused by Heterodera schachtii and Fusarium oxysporum. Biocides that were both fungicidal and nematicidal also controlled the disease, but sugar yields were no higher than those obtained with the plain nematicides. In greenhouse experiments, the interaction between H. schachtii and F. oxysporam was disadvantageous to the nematode. Damage to sugarbeets was less when the fungus and the nematode were present than when only the nematode was present. The fungus inhibited nematode invasion and development in sugarbeet seedlings, thereby decreasing the number of nematodes that matured about 3-fold.