Fungus disease of my Peach Tree

Question

I have a 9 year old standard Elberta Peach tree in my garden. It has been healthy until this year; I had a good crop of peaches in June-July, then during Aug/Sept., I noticed there was something wrong with about 1/3 to 1/2 of the tree. There were many places where sap is oozing from about half of the tree’s branches, and those infected branches changing to a brown/dark color, and possibly getting sick or dying. Also, all the leaves have fallen early from the infected branches. I assume the tree has a fungal disease, but I don’t know which fungus – brown rot, white rot or soft rot, etc. I need your help to identify what fungus I have.

In treating this disease, does your staff believe or recommend that I cut off all the infected branches as soon as possible for the best outcome to save the tree? Or is it safe to leave the infected branches on the tree and use a fungicide spray on a monthly basis this year and next? If you can offer experienced and authoritative advice, I will sincerely appreciate your help.

Thank you.
Dave Johnson
Oakley, Ca

Answer 1

Oozing of sap from fruit trees is known as gummosis, and it is a sign that the tree is under stress, either from diseases or from environmental problems. Here is more information on gummosis:

https://www.gardeningknowhow.com/edible/fruits/fegen/what-is-gummosis.htm

What you describe does sound like a fungal infection, probably with Cytospora canker or with Botryosphaeria fungi. Both of these cause gummosis and can affect sections of the tree with the symptoms you describe.

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/cankers/gummosis-of-fruit-trees.aspx
http://edis.ifas.ufl.edu/hs1265
https://extension.psu.edu/plants/gardening/fphg/stone/diseases/cytospora-canker-of-stone-fruits
http://utahpests.usu.edu/ipm/htm/advisories/treefruit/articleID=12954
https://www.gardeningknowhow.com/plant-problems/disease/weeping-amber-in-trees.htm

These articles describe methods of managing infectious gummosis. However, since fungicide availability varies by state, the best option is to consult an arborist or local university extension officer to learn about the best treatment options available in your state.