Yes @Richard was right on that part where he said its dormant which is why it’s the mystery disease. Just like good and bad gut bacteria in people. That’s not to say it doesnt spread externally it does do that too. Some orchards are constantly spreading infection. The interesting unknown is what triggered it in my orchard this year? There are no cankers i remove trees if they need it. There is no way to know at this time if @alan orchard has trees with dormant fb. There are trees that the bark changes color slightly they have fb but it never is on the outside. Older trees have less vigor and less fireblight damage
3 Likes
I wonder if FB is spread by the birds or bees in my yard, is it possible.
1 Like
Squirrels appear to spread it on my trees or at least open them up to infection when they climb the trees to get at the fruit. They scratch the bark with their claws and break branches, which likely gives the bacteria an entry point. I noticed the branches that were getting robbed by squirrels getting fireblight this year, while untouched trees or branches were spared.
3 Likes
Richard said in CA it spread when trees are dormant which has nothing to do with what you are saying, as far as UC Davis guidelines are concerned. He said that is the time it enters trees while my understanding it that it usually enters though tender new growth, generally in spring (although spring technically comes in winter where Richard lives, but it is biologically spring nevertheless). Tissue in spring is most tender and many diseases are more prevalent then.
Now I’ve learned something, but the questions I now have- does this have anything to do with the diseases spread and how did the bacteria get there in the first place? Does this have any significance at all in the control of the disease or its spread?
Finding some isolated bacteria living within the living tissue of a tree doesn’t mean much by itself. Perhaps it is walled off the way fungus is in trees on a regular basis. The article doesn’t say anything about this being a regular source of inoculum for the diseases spread, does it? Maybe someday that will be discovered to be the case, but is there any evidence of it now?
And do those bacteria eventually multiply and cause symptoms? If so, when?
Without explanations there is no way to know if the discovery of living FB in healthy trees is relevant to controlling fire blight at all. It could be just an irrelevant fun fact- the document is from 1979 (was it even published in a legitimate peer reviewed outlet?) so if that discovery was significant it seems it would have long since made its way into the general literature of how to control FB and its cycle of spread.
The document is almost 50 years old! No corroboration since?
1 Like
I believe too much nitrogen , either from fertilizer application, compost, or just excessively fertile soil, etc…, is the biggest factor that encourages fire blight . Trees with excessive growth are prone to bad fire blight infection. Conversely, trees with low to moderate nitrogen status are much less susceptible.
I push young trees with nitrogen to get them bigger than a deer can eat for about 3yrs…after that I want to slow them down ,aiming for around , on average 10 inches or less of shoot growth . Seldom get fire blight on trees with low nitrogen status.
4 Likes
You have heard of the 65/65 rule. That’s % of humidity and temperature that are fireblight triggers.Pear tree Fireblight research so you dont have to - #18 by clarkinks
3 Likes
Have you tried that Fertilome Fire blight spray. I was hoping that would help
4-n-1: D’Anjou, Bartlett, Bosc, Comice
I have been debating on if I should start over with that avocado tree.
1 Like
Thanks Barry. There has not been any ooze or cankers. And the black seems to be just on the leaves, not the branches.
1 Like
Thank you Dennis. Do you have any recommendations?
1 Like
Thank you so much for sharing.
One things that gives me hope is that I don’t see any quick progression. It seems to stop at the leaf and at most 1/2 of it.
I’m excited to learn from everyone.
1 Like
Yes what would you recommend in place of this?
I also asked in a reply to you, but I will ask just in case you miss it. Have you tried the Fertilome Fire Blight Spray? Now that I think of it, will treating a tree for FB that doesn’t have FB harm it?
1 Like
how would you treat it?
1 Like
Your FB looked like this? Sorry, I just want to make sure I understand.
1 Like
Hey Alan, forgive me if I missed your vote, but do you believe my pear tree has FB?
1 Like
Once it is in the wood, it will not respond to any treatment other than pruning it out. Sprays have to be done preventatively when conditions are ripe for infection. It’s difficult to know for sure whether any given spray application actually prevents anything because symptoms don’t usually present until a couple of weeks after the infection event. And just because conditions were right for infection does not mean there was actually an infection event.
1 Like
Spraying strep on a healthy tree wont hurt it, but I don’t think it would cure it even if it was infected.
Thats a brand new tree that does not appear to have FB. I’d let it grow another couple of years.
1 Like
So I understand, your vote is that it’s not FB. And you recommend letting it grow a while longer to see if more symptoms occur? Cankers, oozing, black branches.
1 Like
I’d just let it be, unless you see progression to the leaf stem and into the node.
1 Like
Thank you
1 Like
I have a Wild Goose plum that I thought was possibly fire blight, but the more I diagnosed I think it may have been caused by either watering causing splashing on the upper limbs, either that or simply heat stress since we are having some record heat days lately. First you might check your local soil conservation service to determine if native soils in your area are low in some of the trace minerals that plants use to uptake nitrogen. That could give you some clues as to what nutrients the plant needs to recover. Then If you have access to an organic soil nutrient that contains most of the trace minerals you could try mixing additional nutrients into the top soil and mulching that with a couple inches of compost. If compost is not available mulch with peat moss. Sometimes new plants need to adjust to new environmental conditions. They tend to suffer transplant shock, maybe when you planted it it was just bad timing. There are many possibilities, but it seems to me the color looks like a nutrient deficiency. So try to treat it for recovery by next spring
Good luck,
Dennis
2 Likes