METHOD: Reproductive Efficiency CONDITIONS: Green House and Field METHOD NARR: In the GH tests # of nematodes and their development were monitored for 8 weeks. A reproductive factor was was calculated. Tuber tests were conducteubers were hand peeled and examined for infection. RESULTS NARR: Development of M. chitwoodi was delayed and only half of the infective nematodes established feeding sites and matured on resistant clones. Blb rarely produs. AUTHOR EXPLANATION: It was possible that a hypersensitive reaction was mainly responsible for the failure of M. chitwoodi to mature normally or deposit large numbers of eggs. The discoloration of infected tissue may haved/or oxidation of phenolic compounds as suggested for certain root-knot nematodes.