Bacterial canker is considered an untreatable infection in stone fruit and cherries.  When the infections become severe enough, the block of trees may be pushed out and replanted for a fresh start.

Our experience indicates it is possible to reverse bacterial canker infections. We can’t point to a specific nutritional profile or disease suppressive soil microbial populations as having produced the resistance. We used soil mineral analysis and plant sap analysis and fine-tuned soil amendments, fertilizers, and foliar applications based on the results. Bacterial canker disappeared from trees that had previously been infected to the point of being destined to be pushed out the following year. Today, these trees are a productive block five years after the initial applications were made.

Lynn Long and I discussed this specific cherry block in our conversation on the podcast here.

John: We’ve worked together on some orchards where we’ve seen some interesting things concerning bacterial canker. At one farm that we at Advancing Eco Agriculture have worked on, the incidence of bacterial canker has been greatly reduced―I think to the point where now, after several years, we can say that it seems to have been eliminated on a couple of blocks. Many growers have asked what we did and what products we used.

And the answer, as Lynn has pointed out so well, is that we don’t know. We worked with nutrition products, we worked with biological products, and we tried to manage that ecosystem. As the ecosystem changed, bacterial canker pressure changed. We can’t point to one thing and say that we did one thing that made a difference. I agree with you that there seems to be the potential to shift that disease in particular, and perhaps others as well. This would be really exceptional.

Lynn: Bacterial canker is a disease that is pretty relentless once it gets into the tree. Occasionally, you’ll find that the canker will dry up and will not progress any further, but much more typically, once it’s established, it will continue to grow and expand and will eventually kill part of the tree, or all of it.

When this grower approached me, he mentioned that he was having some severe infection with bacterial canker. There’s really no effective chemical that you can apply on that tree that is going to stop an infection once it’s started. You can help prevent infections by using some products. One particular product would be copper, but even that’s not all that effective.

When I saw this orchard, there were infection strikes all over the trees. It really did not bode well for the future of that block. But then the grower started to do some of the things we’ve been talking about―using compost and mulching and using some of the AEA products. As I’ve mentioned before, we can’t point a finger to any scientific data that says this turned it around. All we have are observations.

After the first year, the grower came back to me and said that those cankers had dried up. This was in the summertime, and these cankers do go dormant in the summertime. I thought, “Let’s see what they look like in the fall and then in the spring, and we’ll make a better assessment then.” The next spring came around, and the next summer, and the cankers had stopped. For two or three years I went back to that block and continued to look at it, and I saw no more advance of that disease. The oozing that comes about as a result of that disease―from the sap coming out of the tree―had totally stopped. The infections had dried up. It was pretty remarkable. It was quite atypical of what we would have expected for a commercial cherry orchard that was so badly infected. 

P.S. Several weeks ago I wrote about our observations preventing and managing spider mites predations with nutrition, which we have been quite successful with. Today at 4 PM EDT AEA is hosting a webinar where we will describe the plant nutritional profile that allows spider mites to be present, and how you can shift away from this profile. If spider mites are a challenge for your crops, you won’t want to miss it. You can sign up here.