The dreaded F word (Fireblight) is showing up in our orchards


#41

When I had a few apple trees on MM111 I never sprayed anything for fireblight and I never worried about it. The second year after I planted a bunch of dwarf trees on B9, I got clobbered by FB and almost lost the entire orchard and my investment. From what I understand even large orchards run into FB problems when conditions are perfect for the growth of the bacteria. Below is an interesting but sad photo of a commercial orchard in Michigan who lost a big portion of their Gala apples on M9 in 2000 to a FB epidemic.


#42

That’s a sad site to see in an orchard. You never can tell what your going to get hit with.


#43

Oh man, that’s really sad. Out here in southern California I’ve never seen a hint of fireblight on Apples rooted on M111.


#44

Gala is a variety that is highly susceptible to FB.


#45

Good point and M9 is likewise. The two together are a recipe for dead plants. Once the fb gets into the roots it’s game over as the picture attests.


#46

Exactly right. Gala and M9 is not a good combination, especially in a FB prone location like mine. I chose B9 for all my trees due to my concern about FB . Unfortunately, its not very vigorous in my climate and is no longer recommended for commercial plantings in NC. Its good that all my trees were on B9 when I had my FB epidemic. I had to cut the leaders about knee high on a lot of the trees to get rid of the FB. I pulled a lateral up and made it the new leader which worked pretty well. When I had the epidemic, I started by cutting infected shoots and placing them in a 50 gallon trash bag. A week later I filled two pickup trucks with infected material. I followed the standard practice of removing the blight as soon as possible by cutting about a foot below the infection. Unfortunately, the FB kept coming back again and again, Eventually I was advised by the apple PHD to quit cutting the FB out because the huge FB bacterial count my orchard was infecting every new cut . The expert was right and the rate of new shoot infections slowed. The M9 rootstocks would not have survived that trauma.


#47

B9 in studies I’ve seen is one of the lowest yielding rootstock. Lowest yield efficiency which I think is yield/size.


#48

Seeing some hits on blossoms here now

What precisely is meant by “terminal bud set” wrt to FB?


#49

I have seen similar research. M9 beats B9 in a big way in yield efficiency but you have to contend with the FB problem. The Geneva rootstocks with their high yield efficiency and FB tolerance are the obvious choice but they are still in short supply for a standard price ($10). Lots of Geneva at Cummings, but not at prices I can afford. I did notice that Adams County Nursery added a bunch of Geneva rootstocks to their catalog but they were sold out.


#50

Does anyone ever see FB on ornamental crabs? Or are they, as a group, selected specifically for FB resistance?

I cannot ever recall seeing shoot blight or blossom blight on an ornamental crab. But perhaps as a group they bloom too early to be FB susceptible here and have fewer rat-tailed blooms than Malus domestica?


#51

I moved the cuttings to a less humid area that is cooler seems like the Fire Blight is not causing any new damage.


#52

Ornamental crabs do get fireblight here.


#53

Good news for me I hope. No new FB strikes found this morning.


#54

Please excuse my lack of knowledge. What are Altoona and how are you rooting them?


#55

My Altoona, is doing well … I top grafted it on a good size limb. The Altoona is a name given to a saved pear of which we do not know the variety. It came from Altoona IA


#56

My Altoona pears look good also , no strikes


#57

I’m still cutting out fb daily here. It sure does move fast in 1 yr old wood. Remind me to never again let 1 yr wood flower. I didn’t know it could do that. Pulling them below horizontal really works.

Anyone else using the ugly stub approach to pruning out fb? If fb is visible again in the stub a few days after pruning does that mean I didn’t cut back far enough? Or is that expected with the approach. Will it move from the stub into bigger wood or stay isolated in the stub?

We have rain forecast for the next six days. This should be interesting.


#58

I remember you had some really bad FB on yer Priscilla last year, even into the trunk. How is that tree doing this year?


#59

Can’t say we’ve had any strikes yet this year on either our old or new trees, knock on wood. Some of the oldies got hit pretty bad last year.

But, after inspecting my trees this morning, iit looked like I had a deer strike on one of my Winesap branches. Argh… Hate those B&$%#es.


#60

I use it and mark the cut area with dayglow spray paint to make sure I clean it up next winter.

I have seen the problem where FB returns where the first cut was made. I’m not sure if I failed to get all the FB or if the pruning wound provided an entry point for a new infection. Unless the strike is oozing, I would not cut it off unless no rain is expected for several days or perhaps a week. When I had my FB epidemic a few years ago, the more FB I cut out, the more new strikes I got! Often below the area I just removed. Finally the apple PHD told be to quit cutting the strikes out and the problem slowed down.