Kevin,
Just a wild guess. You did spray copper at a rather high dose for an active growing stage of your trees.
Would those young fruit got copper damage? Copper damage causes russeting on fruit. Could it be those fruitlets were so young so the russeting damage were more severe?
Thank you both (@clarkinks and @mamuang). You both offered some great ideas that I’m going to be researching in about 3 minutes! Both seem like more than reasonable theories so I hope I can figure out which one. I’ve seen Clark’s past posts about boron deficiencies so I really ought to get my soil tested either way so I can eliminate this possibility from any future pear problems. Also, I completely agree that if I was seeing that bright orange fungus I’d be convinced it was pacific pear rust, and I still think it is likely the culprit even though I sprayed. I wonder if the timing of my sprays was such that it was off just enough to allow the deformities but prevent the orange “hairs”. WHen I do google image search for PPR it shows pears JUST like mine. Also, this is the first year I’ve seen Pacific Pear Rust (including the orange fungus) on my Bradford pears- which of course I do not spray! So the spores are obviously here on my place.
Tippy, I also think the copper is a distinct possibility. I wasn’t aware that it caused russeting. That might be an important clue because in addition to my little pears being deformed, they also are extremely russeted. So that is a good idea I’m going to consider. Either way, I’ve certainly learned my lesson with full stregth copper after dormancy!! ha.
The russeting could also be frost rings from cold and not copper. Copper is more likely. This is what cold russeting damage and not copper damage looks like.
@Faygo
Copper needs sprayed pre bloom so pears will not russet. Frost rings are based on variety and bloom time. Copper also kills ice forming bacteria which buys you a few extra degrees of cold tolerance at times. At this point its more about how Kevin is going to avoid this problem next year. Copper is used to retard blossom blast and fireblight. If its rust a fungicide spray retards it. Pear Rust. Another fungicide is used with with scab Apple and Pear Scab Management Guidelines--UC IPM
Typically fungicides are already used such as immunox, captan etc. To control the other host of many pear diseases that are possible Disease Control for Home Pear Orchards. These fungicides do not work well on rust and its best to click the rust link to look at the latest developments on the fight with rust.
Clark…after your helpful post I went back to my pears and took a closer look, and now I’m more confused than ever. Mine seem to have 2 patterns of russeting. Many are russetted about half way, starting at the end/bottom of the fruit and going half way toward top. The others seem to have a ring, just as you described. So, do you think this is frost or copper or both. I know I hit them with full copper when they were a little smaller than a marble, but we also had a very slight frost after petal drop so it could be that i guess?.
These are various green euro pear varieties. The pics look a lot like your frost damage but I tend to suspect copper.
Those are frost damaged pears. Very lucky you got a crop! If the russet was from copper it would not be rings only. Picture 2 could be copper. Picture 5 is clearly cold weather. In Kansas our crop frequently looks like that.
Yes the copper likely retarded the ice forming bacteria and saved your crop. I see those rings as victory scars! Copper can russet fruit but was not the culprit this time.
Thanks for the explanation. I have seen similar damage on my early blooming pears. Does the russet from copper affect the pear taste/quality or is it cosmetic?
I have similar frost damage on my early blooming pears this year (especially in a bottom area), with no copper involved. Happy to have fruit considering the alternatives.
Neither copper or frost damage impacts the flavor of the fruit in my opinion. There are situations where the beat up fruit does taste better so i would not ever rule that out
@patrick in 2017 you were one of the first to have such severe damage. Its very common now showing up just about everywhere and its became much easier to diagnose bmsb damage versus stony pit virus versus rust versis boron. See this link for cross reference Is this a result of rust on pears?. Boron issues should also be considered Boron deficiency / Blossom Blast?
Now I’m seeing this on all 3 of my trees and the trees look super healthy. Looks somewhat like above, these are asian pears housi and 20th century. One tree has around 70% and the others are more like 30%. Is it the virus?