Brown spots on leaves of decorative pear tree

Question: I have a decorative pear tree that last year developed some large brown spots on leaves on a section of the tree.  I removed all of the branches with the spotted leaves, but this year it came back on even more that last year (in the surrounding sections).  Any help would be appreciated.

responder: Colorado Master Gardener, Denver County Replied July 27, 2023, 1:12 PM EDT
response: Thank you for your question. Unfortunately we are unable to provide you with an accurate answer. This would best be answered by looking at the plant closely and the photo does not provide enough detail.

responder: The Question Asker Replied August 03, 2023, 1:12 PM EDT
response: Hopefully these pix are ample.  Thanks!       From: ask=<personal data hidden> <ask=<personal data hidden>> on behalf of Ask Extension <<personal data hidden>> Sent: Thursday, July 27, 2023 11:12:08 AM To: rosskelman <<personal data hidden>> Subject: Re: Brown spots on leaves of decorative pear tree (#0111680)

responder: Colorado Master Gardener, Denver County Replied August 03, 2023, 2:43 PM EDT
response: Hi Ross,  Thank you for sending the additional 2 photos; it appears your pear tree is experiencing “Leaf Scorch”. There are a variety of free online resources available to the public and based upon research done at the Colorado State University Horticulture School. Below is an excerpt from Fact Sheet #2.911 on this topic:  “Once leaf scorch has occurred, there is no cure. The dehydrated portions of the leaf will not turn green again, but with proper water management, the plant may recover. Prevention of scorch needs to begin with winter watering. A deep soaking once a month, when there is no snow cover, will help prevent root die-back due to dehydration. The roots of mature trees extend outward several times the height of the tree, and this entire area needs water. To water in winter, choose a day when the air temperature is above freezing and water early enough in the day for the water to soak in before the nighttime freeze. Water that freezes on the surface will cause root suffocation and make the problem worse.  During the growing season, water deeply and as infrequently as possible. This can be difficult when trees are located in or near lawns, but a deep and infrequent watering schedule will benefit your lawn as well, encouraging deep root development. Trees typically need less frequent irrigation than lawns do, but the two can coexist. Remember that roots need oxygen, and this means the soil must be allowed to dry out somewhat between watering."  https://extension.colostate.edu/topic-areas/yard-garden/leaf-scorch-2-911/

responder: The Question Asker Replied August 03, 2023, 8:26 PM EDT
response: Being that the brown patches are sometimes in the middle of the leaf, can this still be leaf scorch?  Is there anything else, that it might also be?   Thanks!   From: ask=<personal data hidden> <ask=<personal data hidden>> on behalf of Ask Extension <<personal data hidden>> Sent: Thursday, August 3, 2023 12:43 PM To: rosskelman <<personal data hidden>> Subject: Re: Brown spots on leaves of decorative pear tree (#0111680)

responder: Colorado Master Gardener, Denver County Replied August 04, 2023, 11:17 AM EDT
response: Another possibility is called anthracnose which is a fungal disease that affects a wide variety of deciduous shrubs and trees and which is more severe in years of cool, wet spring weather. The pathogen overwinters in leaf debris which fits with your description of observing the same thing on your pear last year.  I wish I could give you a definitive diagnosis but I can't based solely on photos. I recommend you submit a sample to the diagnostic lab at the CSU SPUR campus, up at National Western  https://agsci.colostate.edu/soiltestinglab/. That is your best bet for a definitive diagnosis but there is a small fee so, short of that, you could bring a sample to the Denver Extension office in Harvard Gulch Park for them to take a look under a microscope to see if that reveals any fruiting structures https://denver.extension.colostate.edu/ Call first to make sure someone is available<personal data hidden>).