I have come to the disturbing realization that crown gall is damaging and may even be destroying plum trees in my nursery, which is going to cost me thousands of dollars if the worst is true.
I’m just looking for any shared experience about this disease as commercial guidelines are extremely pessimistic. I may just have to destroy scores of trees and try to find new land to start over where the disease doesn’t exist. However, commercial guidelines have tended to be excessively pessimistic in my experience.
For instance, next to the plums I’m growing peaches that have never been stunted by the disease- there’s nothing in the literature I’ve seen that suggest that as even a possibility as it indicates equal susceptibility.
I’m hoping if I keep trees well fertilized that can sustain adequate vigor to be useful trees even if they have minor gall infection on the roots. The literature does say that any infection at all means it exists throughout the tree, however.
Very sorry to hear about this on your plum trees Alan. Can i offer something that seems to help grape growers? Streptomyeces Trichoderma and some of the bacillus have seen to be effective and incredibly high dosages of like actinovate made into a slurry (So like a 1:5 water) or a effective alive Trichoderma harzanium applied at incredibly high strengths. I would also try to apply a broad based beneficial bacteria that gets into the plant maybe something like Quantum Light or something with the Rhodospirillum bacterias. If this is not cost effective you could buy the single bacterias and using a pump air stone and sugar mixture in 5 gallon (or larger buckets) and brew them for 24 hours (multiplying the bacteria) but not over 48 hours (can start brewing other things by then). Trichoderma is multiplied by using rice cooker and the mushroom growing bags and takes about 14 days, this may be too weird and requires a bit of fungal identification knowledge or a few youtube videos.
I think broad based sprays of these at regular rate for all your trees could be beneficial and over time could reduce or remove this infection from heallthy trees. I definitely second giving the trees nutrients to overcome this but before hitting with nitrogen i would make sure they are good on most importantly all micro / trace elements including copper boron sulfur iron P and K.
Before hitting with beneficial bacterias and after cutting out infection sites there is anecdotal evidence of fresh squeezed garlic oil being effective as well as garlic being combined with a strong foliar phosphite spray (although maybe you need leaves and open stomata for this the goal is to absorb the phosphite and the garlic oil in the tree)
On which rootstocks do you see the crown gall problem? According to literature and my experience, Citation is most susceptible to crown gall. Myrobalan is also susceptible but less than Citation. Marianna is supposed to be resistant. One possible solution that should work well for light soil is apricot seedling (should be more resistant to crown gall than any plum or peach) with myrobalan interstem.
I didn’t see crown gall for 15 years then started seeing a little bit and now, over 25 years since my first plum tree order, it is epidemic. Maybe it was the extremely wet seasons recently. Or maybe I got some contaminated trees.
This is sad , if that is your main nursery area.
As it may need to be abandoned as a nursery.
It’s not systemic throughout the tree , as I remember ,such that you could still cut scion wood , well above ground.
But the soil / rootstock are contaminated., and should be kind of "quarantined " . Likely was brought in on contaminated stock.
This is the only effective control I know of, and it won’t stop a infection, but will help protect new uninflected plants from getting infected. Used as a root dip. Still , I would not use that area as a nursery. https://www.evergreengrowers.com/nogall.html
Those are active cultures in the nogall and it states they grow well on peat so you should be able to mass reproduce that as well for your entire orchard.
So i wonder if that is just a weak version of the agrobacterium that lets plants create there own immune response similar to a vaccination or if it actually works with the plant to form a protective layer against other agrobacterium like it states, or if it just outcompetes the other agrobacterium. When you look up Rhizobium rhizogenes you mainly get really interesting results about hairy root disease, it is a gram negative bacterium that is also aerobic. What is your experience with it @Hillbillyhort has it had success to any plants already infected or just as a new dunk before planting?
Black knot at most sites here can be controlled with constant vigilance. I cut out galls as soon as they become visible. As long as trees are in adequate sun this has always worked. But once it gets away from you- all bets are off.
On one occasion I successfully restored an older Santa Rosa plum tree by fiercely butchering it with stub cuts that removed all smaller wood with visible galls- but it was the only plum on the property at the time. When I attempt this at sites with several plum trees completely covered with galls I’ve consistently failed to adequately reduce the disease to make it manageable, although maybe if I could stay on top of it with bi-weekly gall removal it could succeed.
I’ve heard good things about Galltrol or the equivalent NOGALL. Just make sure you don’t dip the roots (spray them). One nursery guy told me years ago that DWN was dipping roots in Galltrol. Because they supposedly overused the solution, they ended up basically inoculating all the trees with R. radiobacter (the causative agent of grown gall) instead of inoculating them with A. radiobacter (active culture in Galltrol and NOGALL).
I have real problems with crown gall in my nursery area, if I reuse it. Once I had about 10 trees in a row I had to pitch because of C. gall. I’ve tried planting them before and the galls get really bad if they are showing C. gall and replanted. Something about digging them up and replanting sends the galls into hyperdrive.
I’ve tried cutting the galls off and replanting, but as you know that doesn’t get rid of the galls because the roots are already affected systemically.
I’ve gotten around this by continually moving my nursery area to virgin ground. If I couldn’t move it, I’d probably try the Galltrol NOGALL route.
I’ve seen some gall on my trees for years and ignored it because my trees seemed to sustain vigor just fine. This year my plums didn’t give me the usual growth and I’m not sure why, but I’m seeing more gall on small trees that I dig up to grow larger out of a fenced area where I start them.
From what I’ve seen, vigorous trees aren’t brought down by the gall in the orchards I’ve planted. However, when trees have failed I haven’t been looking close enough at the roots- I will now.
I think the disease takes over more when the tree can’t outgrow the galls. That’s probably why moving them can be deadly- the reduction in vigor.
Whats scary about the galltral or nogall is it seems like it may be a retarded cousin to the Crown gall and with a high enough application rate you get a non retarded crown gall introduction eventually? I wonder if the cultures could be weakened before application some how and I would definitely not grow anything like that because who knows how they differentiate those bacteriums.
Its amazing how many beneficial bacterias for people are also beneficial to plants and i really try to stick to those but this is obviously more along the lines of bringing a gun to a knife fight.
@Olpea / anyone else with CrownGal experience -
I have a small orchard and last week I pulled out most of my trees. 50% of Myro Plums/Pluots & 50% of citation Plums/Pluots & 30% of roses all had crown gall
Unfortunately due to upcoming travel I rushed and planed new bare root trees in the same area (and I pruned the roots ) New trees are peaches/nectarines/apricots on citation.
Will applying a soil drench of NoGall or Galltrol help offer some protection assuming the bacteria has not already infected the new tree?
I’ve never used it, but heard good things about it. If the trees haven’t been in the ground very long, I think you might benefit w/ No Gall/Galltrol.
Probably to get the best benefit would be to dig up the trees and cut a very small portion of any roots which have already been cut. That way you are removing any bacteria from fresh cuts. Then spray the wounds and the roots with NoGall/Galltrol. I know that’s probably not what you want to hear, but that’s probably the best way. I’m not sure how much benefit you would get by just watering the trees w/ NoGall. It could help some.
If the trees you dug up didn’t have crown gall terribly bad, then you may get by w/ no treatment on your new trees at all.
I have crown gall in my soil, but most of the time it doesn’t affect performance, that I can tell. But we get plenty of water and nutrients in the soil, so even if some roots are girdled, the tree is able to get enough nourishment and water to perform decently. My blackberries are the worst (blackberries are very susc. to crown gall). Last spring I noticed galls even coming out of the ground (first time I’ve noticed that). They seemed to perform OK though.
However if the trees you removed had visible galls from the soil line, that may be too much pressure and warrant treatment.
I think you can order Galltrol from the manufacturer. I don’t know what the minimum order would be or what the shipping would be. Since Galltrol/NoGall are live cultures, they are very perishable. If you buy from a merchant, I would probably ask about the climate control of the storage facilities and make sure the product is not expired. Galltrol says their product lasts 120 days under refrigeration.
No experience but it looks like you want NoGall instead of Galltrol as the K1026 strain is an engineered version of the K84 strain that Galltrol uses (i.e. K1026 less susceptible to infection by pathogenic crown gall strains).