Wilt & fruit fall, Solomon Islands

Members suggested Phytoplasma, Pythium or Phytophthora as the cause, but without a photograph diagnosois is difficult. The complete toppling of papaya is typical of a foot rot caused by Pythium or Phytophthora. P palmivora can cause a wet trunk symptom. P palmivora can start at the top of the plant and usually turns fruit and trunks grey with masses of spores. But if it is predominantly affecting the roots and lower part of the trund (which it commonly does also) then the plants turn yellow, leaves dieback and the plant falls over. If it is the case, improving the drainage around the plants is likely to be beneficial, but really there is not much you can do about it in a small-scale situation except plant in the best drained areas.