of Rhode Island GreenShare Factsheets
of Cucurbits: Bacterial Wilt
vine crops begin to run, gardeners and farmers often notice individual
leaves with severe wilt symptoms on sunny days. Within a week or
two the condition spreads to entire vines which do not recover from
the wilt. This disease, called bacterial wilt, is especially common
in cantaloupes and cucumbers. Squash and pumpkins may not wilt as
rapidly, but may be dwarfed with extensive blossoming and branching.
Watermelons are rarely affected.
of individual leaves or vines of the plant is the characteristic
symptom; one or more leaves wilt and become dull green. The disease
spreads from the leaves downward into the petioles and then into
the stem until the entire plant wilts and dies. Vine borers or soil-borne
fungal pathogens may also cause cucurbits to wilt--a helpful test
in diagnosis of bacterial wilt is to cut off an affected stem near
the ground; if the sap is milky in appearance or sticky and stringy,
the wilting is likely to be a result of bacterial wilt.
bacterium which causes this disease, Erwinia tracheiphila,
overwinters in the bodies of the striped and 12-spotted cucumber
beetles. In the spring, the beetles emerge from the ground and feed
on young plants, introducing bacteria into the leaves or stems.
The bacteria reproduce in the water-conducting vessels, producing
gums which interfere with water transport. The beetles and bacteria
are so intimately related that controlling the beetles will control
infection by the bacteria. Once infection has occurred, however,
no control is possible and wilting plants should be removed, if
practical. The disease is not seed-borne.
of this disease is only possible
through preventing the feeding of cucumber beetles on susceptible
hosts. See GreenShare Factsheet on cucumber
beetles for more information.
the Ohio State University, 2000
are poisonous! Read and follow all safety precautions on labels.
Handle carefully and store in original containers out of reach
of children, pets or livestock. Dispose of empty containers
immediately, in a safe manner and place. Pesticides should never
be stored with foods or in areas where people eat.
When trade names are used for identification, no product endorsement
is implied, nor is discrimination intended against similar materials.
Be sure that the pesticide you intend to use is registered for
the state of use.
The user of this information assumes all risk for personal injury
or property damage.
of Rhode Island Cooperative Extension provides equal program