How do I check my greenhouse for bacterial wilt?
Bacterial wilt disease causes rapid wilting and death of the entire plant without any yellowing or spotting of leaves. All branches wilt at about the same time. When the stem of a wilted plant is cut across, the pith has a darkened, water-soaked appearance. There is a greyish slimy ooze on pressing the stem. In later stages of the disease, decay of the pith may cause extensive hollowing of the stem. Bacterial wilt causes no spotting of the fruits. Affected roots decay, becoming dark brown to black in colour. If the soil is moist, diseased roots become soft and slimy.
The best method is to determine presence of bacterial wilt on your farm is using a water test. Take a thin slice or sliver of the brown stem tissue and place it on the inside of a glass of water at the water level. If bacterial wilt is present, a milky bacterial stream (strands) flows from the lower cut surface of the sliver within seconds.
|Water test for detection of bacterial wilt. Note bacterial strands oozing from infected tissue.|
|© A. M. Varela and A. A. Seif, icipe|