Dying trees

Question: First, my cherry tree died. Then it was one of my Italian prunes, then a greengage plum, and now my other greengage tree looks like this. Two of the branches have leaves that are completely dead. Two more have leaves that are yellowing. What should I do?

responder: D.Lauer Benton County Master Gardener Replied June 09, 2023, 6:39 PM EDT
response: Hi there Bernice!  Can you give me the time period encompassing the tree deaths and the current tree issues.  When did this all start? How long from noticing the tree symptoms till tree death in previous victims? Are we talking last year or two or all this year?  Also, how close together are all these trees? Are any other trees showing early symptoms?  Thanks.

responder: The Question Asker Replied June 09, 2023, 7:02 PM EDT
response: The cherry tree is 40 or 50 feet from the plum and prune trees which are 10 to 15 feet apart. The cherry tree went first last summer. First one branch would die, so I cut it off, then another branch, then a third, several weeks apart. There was some sappy weeping on the trunk. I clean my shears with bleach after cutting. All the branches that were left set flowers this spring, but they dried up before setting fruit or leaves.The first prune to go went last summer. Its leaves started turning yellow midsummer. It did not bloom nor set leaves this year. I took it out when I realized it was dead. Incidentally , I did not get any fruit last year on any of the plums or prunes because they bloomed before the pollinators came out.The next to go was one of the green gage trees. It looked fine this spring, but then the blossoms dried up and no leaves appeared.The other green gage tree looked fine until a couple of weeks ago, then its leaves started to yellow. It still has a few fruit.I only have one drupe left, a prune. Right now it looks healthy with green leaves and a normal amount of fruit.My apple, pear, and fig trees all look okay as do the native Indian plum, currant and service berry plants.Thanks for your help.BerniceSent from Yahoo Mail for iPadOn Friday, June 9, 2023, 3:39 PM, Ask Extension <<personal data hidden>> wrote:

responder: D.Lauer Benton County Master Gardener Replied June 11, 2023, 4:08 PM EDT
response: Hi again Bernice. I have been looking at your photo and description of what has happened to your fruit trees. Without more photos at the stages of what occurred I have determined that it could be a couple of culprits that are common because of our wet cool Springs.   The first is a fungal disease that is called flowering brown rot disease. It is characterized by blossoms that seem to dry up followed by yellowing leaves and then by twig and branch die back. There is also some gumming or sap. Good orchard sanitation, raking up leaves, cutting off dead branches in conjunction with a preventative spray program can do a lot to help with this disease. Remove and destroy infected leaves, wood, and mummified fruits from your orchard. Be sure to remove any mummified fruits on the trees and from the ground from previous years. If not done the amount of inoculum continues to build up and infections become progressively worse. https://pnwhandbooks.org/plantdisease/host-disease/plum-flowering-brown-rot-blossom-blight As with any fungal disease anything you can do to improve air circulation will also help. Pruning to maintain an open canopy and perhaps modifying fencing near trees to allow air to circulate more freely could help. Please note that Bonide Fung-onil Multi-purpose Fungicide at 2.25 teaspoons/gal water. Group M5 fungicide is the only chemical listed for Homeowner use.   The second possibility is a bacterial disease. Here is a link. That discusses it. https://pnwhandbooks.org/plantdisease/host-disease/cherry-prunus-spp-bacterial-canker Please note that there are several chemicals that are available for homeowner use against this disease. In the Chemical control area use the chemicals that have a capital H in a square box behind the listed chemical. You can also use chemicals that have a capital H and O in square boxes after the chemical listed.  I did not ask you if you did any preventative spraying to protect your trees. Below is a link that provides guidance on when and what to spray. If you live in certain counties of Oregon there is a requirement to treat your home orchard trees to prevent the spread of disease to commercial orchards. This document will also tell you If you are in a country that require preventative sprays. https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/ec631.pdf “Managing Insects and Diseases in Home Orchards.” This document discusses preventative chemicals to prevent infection by diseases.  I hope that this information helps you.

responder: The Question Asker Replied June 11, 2023, 4:59 PM EDT
response: Thank you! I’m guessing it may be the fungal infection because there were some mummified fruit last year. I have to admit to not being good about picking up after leaves and fruit falls. When you say destroy the leaves, branches, etc. are you meaning burning them?Sent from Yahoo Mail for iPadOn Sunday, June 11, 2023, 1:08 PM, Ask Extension <<personal data hidden>> wrote:

responder: D.Lauer Benton County Master Gardener Replied June 11, 2023, 9:10 PM EDT
response: It may be a little late in to burn this year. You need to get them off your property to reduce inoculum reserve for reinfections next year.  Land fill or hot composting facility are also choices. Be sure to follow up with preventative sprays at the proper times as discussed in 'Managing Insects and Disease in Home Orchards' and if the disease reemerges next year with treatment sprays.