What is that white substance. It looks like the tree has been heavily sprayed with something while it was blossoming and that killed the blossoms.

Lime-sulphur?

With home trees & gardens truly, truly, truly, less is more with regards to sprays, fertilizers, and the like.

Even in most commercial farming situations these treatments are done more to give the produce a waxy artistic look rather than actually needing the treatments in most situations. The losses would be negligible if the commercial farmer removed one diseased tree and replaced rather than treat the whole orchard but they must have that unblemished produce.

I'm just being truthful here.

The white substance is Surround, a clay substance intended to deter insects with physical irritation, without toxicity. I sprayed after 95% petal fall- I have a few trees which bloomed quite late, which I mostly skipped.

Looks like that is the cause of the fruit kill. Sorry. Next year.

I doubt that is the cause. It is widely used and I haven't seen any reports of Surround causing this. Also, I remember being a bit worried about set, particularly on this tree, when I first sprayed. I put a few coats of Surround on just in case, but I didn't see many apples which had clearly set. Looking now, I see a total of 1 apple on the tree.

You'll find it's isn't fire blight. The cause was the spray.

OK, I've attached a link that shows that you use kaolin spray after apples have formed. You killed the formation of the fruit by clogging the respiration of the fruit with ultra-fine kaolin clay.

Here is a link that might be useful: Link to University of Washington Home Apple Spraying Schedule

AgroCoders:

Surround is totally inert with regards to the trees and fruit. It's just clay. I'd suggest you quit posting so much when you don't know what you are talking about. You've repeatedly given ill informed posts on multiple topics.

Oh, I know what I'm talking about. You don't. You ignored the directions for use and killed your apples.

Do the same thing next year and kill your apples again.

I did not just fall off the turnip truck you know.

Agro, you did just fall off the turnip truck and must have hit your head if you dismiss FN's input. Show some respect for those whose experience far surpasses your own. He would never bark at another contributor unless they were doing real harm.

Surround does not kill flowers. I'm in the northeast and my unsprayed flowers of certain varieties suffered the same symptoms, probably because the flowers were weak to begin with and then faced many cool wet days just as they opened.

That is not FB either, IMO..

For what it's worth, I've been fighting fireblight for the first time on one of my apple trees and I've had blossom blight like in your pictures. Various new growth with the drooped over tip like in classic fireblight pictures, etc. (see attached picture...sorry for the blurriness) This is a 4-1 apple tree and I've pruned away at least 50% of the one variety. I think I caught up with it.

Do you have any cankers on your tree or other visible fireblight signs like new growth turning black and drooping?

And I've never heard of surround hurting flowers. For anyone who thinks so, find me one google link that describes that issue.

Bob, that looks like blossom blight to me. I've had a lot of it some years. The Surround has nothing to do with it.

Scott

Thanks All.

Harvestman, I checked back on my notes and last month's weather (from the Weather Channel- I don't keep notes on temps :) ). The tree opened first blooms on 5/2, and was likely at full bloom when we had 4 days of rain starting on 5/7. The first 3 days were mostly in the 50's, while the 4th day heated up to almost 80. I'm hoping for this to explain it, but it is also possible that the cold/wet conditions encouraged FB. I should also note that the Hudson's Golden Gem tree less than 10 feet away bloomed within 1 day of the Red Boskoop (they were two of the first trees both this year and last) and HGG is covered with apples (I've had to thin quite a bit).

Sharppa, I haven't seen any other signs of FB, so I am crossing my fingers. I did a quick check for cankers and didn't see any earlier today. I'll keep an eye out for it though.

Scott, how do you normally deal with blossom blight? Does it normally spread into the trees? I'm not sure how much I need to prune off, given it seems to be pretty dry and not spreading further (that I can see).

My Jonathon had a lot of that on the western side of it but healthy apples forming on the top and eastern side of it, which indicates to me that the blossoms stayed wet too long on the western side of the tree. I've had this happen to Asian pears before. It could be blossom blight- there was no active fungicide in the tree, but I would expect the pathogen to infect flowers all over the tree. Same thing also happened with my Braebern.

Both these varieties have whimpy flowers..

Bob I just pull off the blossoms and dispose of them. This helps reduce the amount of pathogen in the orchard. This year I had only a couple clusters total get infected but I have had hundreds some years.

Scott

Last year, one of the lower braches on my 20th century pear had something very similar to Bob's picture showed. All flower clusters along the entire lenght of that branch shriveled and turned brown. Leaves and the branche were not affected.

At the time, I did not take a picture or bother to ask here. Now, I know it's blossom blight and I should have done what Scott suggested.

This year, that tree has not flowers likely a result of overbearing last year. That branch is in fine condition as the rest of the tree.

I'll keep an eye on that tree next year but don't plan to spray for blight yet. Hopefully, it's a one year trouble.

Yes, in the 20 + years i've been growing bearing age asian pears it only happened once and i never apply fungicide to a. pears.

I'm not even sure it can be controlled with fungicide as my helper at the time had seen it in a commercial orchard where they spray like there's no tomorrow.

Thanks Scott. I'll pull them off. I'm glad I don't need more drastic action.

Hopefully we have a better spring next year. But, a warmer spring could lead to a late frost, so it is a bit of a balancing act.

I think I also have blossom blight on my North Star sour cherry(below pic). It has the same type of issue, but since cherry aren't susceptible to fireblight, I think it may be brown rot (see below link). I notice more on the bottom and inside of the tree. Maybe I need to open it up a bit more next year. I'll definitely clear off the dead clusters, hopefully before it can get to the nearby peaches.

Here is a link that might be useful: Brown rot blossom blight on sour cherry

There are almost no sweet cherries here this year. Never seen them completely wiped out by rainy conditions just as they were forming before. It might have been the one really warm night from what I've read recently about apples losing blossoms. Apparently wet and warm can be worse than cool and wet- not only because it serves fungus but because it weakens the tree when it is cloudy but warm at night- trees use more energy when it is warm.