Bacterial Canker Symptoms
Peach bacterial canker is associated with a syndrome called Peach Tree Short Life. With a name like that, it is evident what the ultimate outcome is without adequate peach bacterial canker control. It is a slow death that results in an unhealthy tree with little to no fruit and an untimely demise. It can be hard to initially recognize bacterial canker on peach trees. By the time your eyes can see the signs, the tree is likely in great distress. The bacteria causes the most damage when trees are dormant or unhealthy for other reasons. Just at leaf break, cankers form on stem and trunk tissue. These develop copious amounts of gum that eventually breaks through the plant matter. The result is a sticky, smelly, cancerous lesion. Prior to this, the plant may experience tip die back and some leaf distortion. Once the canker is filled with the gum, any plant material beyond it will die.
What Causes Peach Bacterial Canker?
The pathogen is the bacterium Pseudomonas syringae, but its effects rely upon conditional and cultural situations. The disease progresses rapidly in rainy, cool weather and is dispersed by windy conditions. Any small injury in a plant can invite the introduction of the disease. Freeze damage and winter injury are the most frequent ways the pathogen gets into the tree. The disease development stops during warm periods, however, the bacteria overwinters in buds, margins of cankers, and the tree itself. The following spring brings forth more growth of the disease and potential spread.
Peach Bacterial Canker Control
Good cultural conditions can prevent much of the damage from this disease. At planting, select sites that are well draining and use rootstocks that are resistant to the pathogen. Keeping the tree healthy with suggested peach fertilizing, minimizing other disease and pest issues, and proper pruning techniques can also diminish the effects of the disease. Sanitary practices on all tools used can reduce the transfer of the bacteria from tree to tree. Some growers suggest treating peach bacterial canker by pruning in January or February. Remove at least 12 inches (31 cm.) below cankers and dispose of the infected tree material. Another suggestion is an application of copper fungicide just at leaf drop, but this seems to have minimal effect.
