Bacterial Wilt

Cucumber leaf with bacterial wiltAn early symptom of bacterial wilt is drooping leaves on squash or cucumber vines — even when the plants have been well watered. This happens because the wilt bacteria clog the vascular systems of plants, blocking the flow of water and nutrients from the roots to the leaves. If infected stems are cut open, they may release a milky sap. As the disease spreads, leaves turn brown. Eventually the entire plant shrivels and dies.

Bacterial wilt can occur in all plants in the squash family except watermelons; another type of bacterial wilt can infect tomatoes and beans. There?s a direct link between bacterial wilt and insects. The bacterium overwinters in the gut of cucumber beetles and grasshoppers; when these insects emerge the following spring, they spread the bacterium as they feed. The severity of disease is typically proportional to the amount of feeding by the host insects.

Prevention and Control

  • Plant disease-free seed, and choose wilt-resistant cucumber varieties such as County Fair.
  • Prevent cucumber beetle from feeding on susceptible plants.
  • Keep plants in good health; cucumber beetles are more likely to target weakened plants.
  • Uproot and destroy infected plants or add them to a hot compost pile.

Last updated: 03/18/2024