Gummosis can be described as a situation in which there is a discharge of sap or gum from a tree. It is mostly associated with stone fruits, apricots, peaches, and plums.
This behavior in trees is caused by a number of factors which will be explained in the course of this read.
The most prevalent factor attributed to gummosis in trees is caused by a fungus known as Cytospora, now called Leucostoma.
Interestingly, gummosis can only infect vulnerable weakened trees which have been stressed over time resulting in wounds on the tree.
Also, cuts inflicted on trees as a result of pruning is another cause for gummosis infection. Natural factors like Sunscald and even extreme cold temperature can also provide an opportunity for gummosis infection on your tree.
The only way to prevent this infection is via prevention.
TWO LEUCOSTOMA SPECIES INFECT FRUIT TREES
There are believed to be two species of Leucostoma that infects trees which are; L. persoonii and L. cincta.
L. persoonii infection is mostly associated with stone fruits, apricots, plums, peaches, and cherries which are grown at a low elevation in warmer climates.
L.cincta on the other hand, is associated with apples and cherries grown at a high elevation in cooler areas.
The two species of fungus are known to be prevalent across the United States, throughout British Columbia and Ontario, Canada. Haven caused problems in states such as South America, Europe, and Japan.
HOW TO DIAGNOSE GUMMOSIS DUE TO LEUCOSTOMA CANKER
Trees with symptoms of gummosis normally display signs of tree flagging looking worn out, and bearing a different texture and color from other parts of the tree.
The Leucostoma fungi leaves an imprint of a dark amber color on the part of the tree it infects. Once scrapped off, the phloem beneath the tree’s bark takes the color of cinnamon brown.
Normally, it is common to see the effect of gummosis on trees during the periods of winter and spring. However, the tree is able to fight back the infection when it starts growing again, but unable to do so in the fall. This effect on trees can be seen in periods when tree tissues take on a lighter or darker color.
In order to ascertain if the infection is caused by Leucostoma canker or other causes, a look at the tree’s fruiting bodies – identified where you can find protrusions on the surface of the tree’s tissues that takes the form of small black pimples.
The fruiting creates thousands of spores on the tree’s tissue, while those of L.persoonii can travel as high as 260 feet.
HOW TO PREVENT GUMMOSIS
- OPTIMAL FERTILIZATION AND CARE
Haven being aware the opportunistic infection gummosis can only attack vulnerable and worn out trees, you should practice healthy mulching, water and nutrition.
Take steps to fertilizing with nitrogen during the periods of late winter or early spring. This should be done to prevent your tree from being vulnerable as a result of cold in the fall.
- PRUNE PRECISELY AND REMOVE DAMAGED TISSUE
It is important to take utmost care when pruning so as to avoid cuts on your tree. You should not prune in wet or cold weather. While pruning, make proper cuts such as leaving stubs, flat cuts, and flush cuts will make your tree vulnerable to gummosis.
You can prune back to healthy wood by carefully taking out the infected limbs and twigs from off your tree. This should be done during periods of dry weather conditions so as to provide a conducive atmosphere for the wound to heal in quick time.
Also disinfect your tools between cuts with Lysol wipes or 10% bleach solution.
Note that in cases where there is extensive damage to your tree, it may not be possible to prune out all the parts that the fungus has spread to.
- PROTECT FROM SUNSCALD
To prevent a gummosis infection as a result sunscald during winter, you can consider any of these two solutions:
The first is to paint your tree with half white latex and half water-based paint.
Your second choice is to apply white tree wrap on your trees from December to March.
- PROTECT AGAINST RODENTS AND INSECTS
You should take protective measures in treating rodents and insect attacks on your tree. Simply spray insecticides to keep off borers from boring holes on your tree.
- DRAIN WATER FROM THE BASE OF THE TREE
This can be adopted as a preventive medium against gummosis infection to the base of your tree in cold weather conditions. All you need do is drain out water from the tree’s base.
If you reside in areas where there is a large concentration of this fungus, it is important to constantly treat your tree with chemicals that help prevent its attack.
Make use of captan, thiophanate-methyl, or lime sulfur (Bordeaux mixture) in 50% latex or kaolin clay to areas to freshly cut pruning wounds. Do not use copper hydroxide-based chemicals as it is toxic to trees.
MONITOR YOUR TREE CLOSELY
Always endeavor to keep an eye on your trees to check if there are any parts with wounds or worn out.
It is common to find Leucostoma canker attacks in backyard trees, therefore great care should be taken while pruning to prevent cuts. However, if in the event of pruning you inflict cuts resulting in wounds on the tree, apply a chemical treatment. This will help prevent the fungus attack.
Keep a close watch for gummosis infection on your tree. Where you find any, determine if it was caused by fungal injury. When sure, take out the damaged tissue before it spreads by pruning back to healthy wood.
In the event you lose a tree to gummosis, completely take off such tree from the root to prevent it from spreading to other trees as the fungus have discovered to continue living on dead tissue.
If you have experienced and successfully treated a gummosis attack on your tree, let us know how you did it