Agriculture Reference
In-Depth Information
Fig 12.7 Bacterial black spot symptoms on a leaf.
infested planting material. Bacteria enter through natural
openings on leaves (stomata) and fruit (lenticels) or
through abrasions. Disease incidence is greater on exposed
and abraded leaf and fruit surfaces, or where fruit touch
each other. Infected nursery trees have been a major means
of spread of the disease into new orchards.
Fig 12.5 Bacterial black spot symptoms on fruit.
Importance
Bacterial leaf spot is a destructive leaf, stem and fruit
disease occurring throughout Australia's mango-production
areas and in most countries where susceptible cultivars are
grown. The cultivar Kensington Pride, and many of the
commercial cultivars grown throughout the world have a
relatively high susceptibility to the disease. Bacterial black
spot is particularly severe in exposed, windy areas where
adequate windbreaks are not present and where trees lack
vigour. The disease can be prevalent in both low- and high-
rainfall areas, since persistent dew in combination with
wind rub permits extensive infection and disease
development.
Management
•
Preharvest management measures are essential.
Use disease-free rootstocks and scion-wood.
•
Spray rootstocks and disinfect scion-wood with
recommended chemicals.
•
Fig 12.6 Raised, black spots are symptomatic on some mango varieties.
