Plantwise Factsheets for Farmers
Control of Black Rot in Cabbage
campestris pv. campestris
Recognize the problem
The disease is caused by bacteria and can be identified on the leaf
as a “V” shaped yellow colour, moving from the edge inwards and downwards into
the stem. This symptom distinguishes Black rot from Fusarium wilt where symptoms move upwards from the soil level
towards the stem.
As the disease progresses, the yellowing part of the leaf turns
brown and the tissues die. Leaf veins turn black at the final stage of the
Black rot is one of the
most serious diseases of cabbage in Grenada. It poses a big problem in areas of
high humidity, reducing crop yields by as much as 75-90%. The bacteria that
cause Black Rot can survive and spread via wild hosts, soil, water droplets or
Avoid growing very susceptible varieties in the
rainy season. There are no resistant varieties in Grenada.
- Do not plant cabbage in a field
that has had cabbage, broccoli, cauliflower, kale or any other member of the
Brassica family for the previous 3 years
- Avoid using overhead sprinklers
because they can cause soil to splash on leaves and so will spread the disease
- Control weeds in and around the
production area, especially weeds from the cabbage family
- Do not enter fields when they
are wet to reduce the risk of transferring the disease from one leaf to another
by moisture on the leaves
- Prune off all leaves close to
the ground and leaves that show signs of the disease (use clean tools regularly
dipped in bleach)
- Bury or burn all crop debris
- Spray Copper Hydroxide (e.g.
Kocide 101, Champion, or Coback) on the entire plant, paying attention to the
underside of the leaves, at a rate of 2-4 Tbsp per U.S
When using a pesticide, always wear protective clothing and follow the instructions on the product label, such as dosage, timing of application, and pre-harvest interval.
The recommendations in this factsheet are relevant to:
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