I have a mature yellow plum tree which in recent years has been developing a problem causing the fruit to malform soon after forming. The problem has inreased over the last ten years. When the fruit is near ripening late July 50 percent of the remaining non deformed plums rot on the tree resulting in a loss of most of the crop. The trouble has only started in recent years I never had the problem originally. I haven't been able to obtain any help from various garden centres, any answers.

Tom

Tom thacker wrote:
I have a mature yellow plum tree which in recent years has been
developing a problem causing the fruit to malform soon after forming.
The problem has inreased over the last ten years. When the fruit is
near ripening late July 50 percent of the remaining non deformed
plums rot on the tree resulting in a loss of most of the crop. The
trouble has only started in recent years I never had the problem
originally. I haven't been able to obtain any help from various
garden centres, any answers.

Tom

This sounds like a fungal or bacterial attack on the fruit. You need to
find out which one before deciding on treatment. Any chance of a picture?

D

Thanks for the reply I attach a photo of recently removed deformed plums. Hope the photo appears with this message as it's the first pic I have posted

Plum trees are prone to the plum pocket disease caused by the Taphrina communis and Taphrina pruni fungi. T. communis is found in plum trees all over the world. The disease starts with the appearance of white, blistery spots on the fruit. The affected fruit tissue enlarges rapidly and makes fruit abnormally large sized. The seeds of infected fruit are destroyed entirely, leaving only a large, empty cavity within the swollen, rotting fruit. The fruit is spongy in texture and turns gray as the rotting worsens with visible mass spore production. Other ba href="http://advancednutrients.com/hydroponics/articles/fruit-trees-ornamentals"fruit trees/a/b part such as foliage and twigs are rarely affected.

The fungal spores produced on infected trees during spring and summer overwinter under the bud scales and tree bark. These spores start to infect new growth the following spring as they are spread through the tree by splashing water, rain and wind. Cool and wet springs favor rapid spore germination. Debris under the tree consisting of infected previous year fruit also becomes a frequent source of infection in new growth.

Using dormant fungicides on trees is among the preventive measures to keep the disease from infecting trees during spring. The fungicides will not cure disease after the infection has occurred. Recommended time to spray trees is when the tree is dormant and before bud swell or appearance of flowers. In cases where the infection had been severe during the past year, it is best to spray the tree twice -- once during late fall and then again during early spring. Recommended fungicides include products containing chlorothalonil or liquid lime-sulfur.

Plum trees are prone to the plum pocket disease caused by the Taphrina communis and Taphrina pruni fungi. T. communis is found in plum trees all over the world. The disease starts with the appearance of white, blistery spots on the fruit. The affected fruit tissue enlarges rapidly and makes fruit abnormally large sized. The seeds of infected fruit are destroyed entirely, leaving only a large, empty cavity within the swollen, rotting fruit. The fruit is spongy in texture and turns gray as the rotting worsens with visible mass spore production. Other fruit trees part such as foliage and twigs are rarely affected.

The fungal spores produced on infected trees during spring and summer overwinter under the bud scales and tree bark. These spores start to infect new growth the following spring as they are spread through the tree by splashing water, rain and wind. Cool and wet springs favor rapid spore germination. Debris under the tree consisting of infected previous year fruit also becomes a frequent source of infection in new growth.

Using dormant fungicides on trees is among the preventive measures to keep the disease from infecting trees during spring. The fungicides will not cure disease after the infection has occurred. Recommended time to spray trees is when the tree is dormant and before bud swell or appearance of flowers. In cases where the infection had been severe during the past year, it is best to spray the tree twice -- once during late fall and then again during early spring. Recommended fungicides include products containing chlorothalonil or liquid lime-sulfur.

Thanks for the comprehensive advice regarding the plum tree disease, and the recommended treatment. I will make enquries at my local garden centre for the fungicides and start treatment this autumn.

Regareds Tom