( Erwinia amylovora )
First appearing in the British Isles in 1957, this bacterial infection attacks the Rosaceae Family. Individual branches wilt and the leaves turn a burnt chestnut colour. This spreads down to the main trunk and affects the rest of the plant until the whole tree or bush looks burnt. The bacteria enter via stomata and lenticils in the leaf and the flowers (esp. pears). It is carried by pollinating and other insects and by raindrops. Favoured conditions are increased humidity and temperatures above 18°C between June and September. The bacteria lodge in the xylem and if cut a brown stain will be seen on the outer edges where the current annual ring of it is situated. In severe infections a spreading brown, bacterial slime may appear through the bark.
Pears, hawthorne and cotoneaster are most prone, less so apples and pyracantha. This disease must be notified to the Ministry of Agriculture in fruit growing areas of England and anywhere in Northern Ireland, Isle of Man, Eire and the Channel Isles.
Affected plants should be removed and burnt. When caught early pruning out affected stems to 60cm beyond the nearest healthy growth may save the plant. Avoid planting hawthorne hedges near to pear trees. Sterilize any pruning instruments used and seal the wound with protective paint.
There is no chemical control.
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