Help Identify this Pear Disease

[Rit]

Fungal Infections

Pear tree leaves, fruit, twigs and branches can become infected by fungus. Some of the symptoms of fungal infection are black spots on leaves or stems, early leaf drop or curling and blackening of the leaves. Flyspeck, sooty blotch, fabraea leaf spot and pear scab are all fungal infections commonly affecting pear trees. Prevent fungal infections by removing fallen fruit and leaves promptly, disposing of these away from the pear tree itself. Treat fungal infections with fungicidal sprays. Follow the directions on the fungicide label for correct application.

fabraea leaf spot .... that's my guess ....

"Symptoms & Signs
Fabraea most noticeably first manifests itself as small, purple-black spots on leaves and fruit. Spots gradually enlarge into brown lesions 1/8 to ¼ inch in diameter. When the infection is severe, defoliation can occur and fruit will become deformed and not sellable and/or drop off the tree. Fabraea may also infect shoots, again appearing initially as purplish spots, becoming lesions/cankers which may persist into the next growing season. Leaf and fruit infections are most notable in the Northeast and Midwest, but in the Southeast , shoot infection can be significant. Severe infections can result in reduced flower bud formation for the following season."

"Disease Cycle
Similar to apple scab, much Fabraea overwinters in leaves on the orchard floor. Farther south, overwintering is also likely to occur in shoot cankers. Spores are released from leaves with rain from mid-May to July (in the Northeast and Midwest) and result in primary infection on fruit and foliage. Shoot cankers spread Fabraea from late-April through May (in the Southeast) with more driving rains. Length of wetting for infection to occur can range from 12 hours at 50 degrees F. to as little as 8 hours from 68 to 77 degrees F. Infections take about 7 days to become visible. Once primary infection occurs, secondary infection can spread rapidly with rain and wind during the summer, particularly during wet seasons."

"Chemical Control
Contact/protectant fungicides are necessary to control Fabraea leaf spot. EBDC fungicides (Manzate, Penncozeb, Dithane) and Ziram give good control. (But EBDC’s have a 77 day Pre-Harvest Interval.) Early season fungicide application(s) for pear scab (as long as EBDC’s or Ziram are included) will prevent initial infection by Fabraea. Where disease pressure is high, however, summer-long fungicide applications (once the pear scab season has passed) will be required, particularly in wet summers. Late-maturing varieties may even need fungicide sprays into the early fall to prevent Fabraea from infecting fruit."

Wow thanks for taking the time to put that together.

 

[OakSeeds]

My pleasure Mr. Rit; after all, we're all here to learn from and help each other. Besides, it's way too wet to attempt to get anything done in the woods today. Hoping for sun tomorrow.

 

[J B]

I’ve had bad luck with Bartlett pears this year. Both 9-10 year old trees. A little fire blight last year, but I’m pretty low maintenance on my trees (plant volume) so I did not cut it back. One is completely dead now. The other one had a lot of die back. Maybe this some of this damage was done with the very cold temps last winter? One tree does have some bark damage on the south side and it’s on a south facing hillside. I have some Potomac and Shenandoah pears. Both of them seem to be doing just ok. My younger Geo/Keifer pears seem to be doing better. So far, I’ve had better luck with apples here.

 

[blueKYstream]

I checked that pear tree again a couple weeks ago and then yesterday. On July 2, I noticed a bunch of little black "crusties" on the leaves. If you touch the leaves they roll off. I don't figure they were a big deal. Yesterday, I checked and it appears that pear scab has returned again this year. I'm wondering if this tree will be an ongoing diseased tree and I should convert it to another pear?

Not sure what those crusties are (July 2)


This half the tree has scab bad (July 12):

This side not quite as bad:


P.S. the leaves are wet, because I sprayed it with fungicide after taking the picture.

 

[TreeDaddy]

Has Native Hunter seen these pics?

Once seen ,he will identify and end the thread

bill

 

[Prof.Kent]

Black leaf spot. Fungal infection. Is not fireblight.

 

[blueKYstream]

Black leaf spot. Fungal infection. Is not fireblight.

Yeah, I think you're right about black leaf spot or Fabraea maculata. I planted the tree in early summer last year and had that issue. It dropped 3 sets of leaves before finishing out the year looking clean. Clearly, the problem reared it's head again this year. None of the other pears nearby appear to be affected at this time. I'm curious if it makes sense to try to convert this tree to another cultivar (I'm assuming in the late winter) or wait it out and see if it corrects itself?