Bacterial wilt. Insert: Bacterial ooze.
Bacterial wilt diagnostic Test.
Bacterial wilt of cucumber.
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PROBLEM:
A few leaves wilt and dry and may be chewed. Wilted leaves often recover at
night, but they wilt again on sunny days and finally die. Fruit shrivels.
Cutting a wilted stem near the base of the plant and squeezing out the sap
produces a milky white substance. Touch a knife to the sap and withdraw it
slowly. If the plant is infected with bacterial wilt, white ooze will string
out in a fine thread. ANALYSIS: Bacterial wilt
This plant disease is caused by a bacterium (Erwinia tracheiphila) and is more
prevalent on cucumbers and muskmelons than on pumpkins and squash. Watermelons
are not affected. The bacteria spend the winter in
striped or spotted cucumber beetles and are
spread to plants when the beetles feed. An entire plant may become infected
within 15 days. The disease is most prevalent in cool weather in areas with
moderate rainfall.
SOLUTION:
There are no chemical controls for bacterial wilt. Remove and discard all
infected plants promptly. Control cucumber
beetles with a chemical containing carbaryl (SEVIN) or diazinon. Repeat the
treatment every 7 days if the plants become reinfected. Grow varieties
resistant to this disease. There are no resistant muskmelon varieties.
Cucumber variety resistant to bacterial wilt: Saladin.
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