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Bad fungus on my peach tree!!

 
Brady Stark
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I am volunteering in Italy for a man with a hillside farm and orchard. He has had increasing interest in permaculture over last 30 years and always trying new things. There is a peach tree in the orchard that gives wonderful fruit but he claims that it will only produce with a heavy chemical treatment. There is a fungus in the area that attacks the leaves and decimates its production. For all my research I can't find an Eco friendly answer. Anyone with some tips or references would be greatly appreciated. I'll try and post some pictures of the infected leaves soon for identification. Thanks!
 
leila hamaya
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yeah the peach leaf curl is a b!+@% !

it really sucks.....and its really common. so common i am fairly certain this is what you are talking about.

from what people tell me locally it is more intense in areas with thick forest and lots of conifers, as where i live. i have never heard of an effective way to deal with it, other than yearly spraying. if anyone knows of something, or has even a wild guess, i'm all ears =)

i think theres are a few varieties of peaches that dont get it, such as the blood peaches? or others?

almost all the local peach trees have it and people can only control it by spraying it with something each fall/early winter. being a fungus its extremely difficult to nearly impossible to get rid of it. all that can be done is to try to restrain it each year. at least, peaches can still be harvested from the trees, though probably productivity is much lowered. if people spray for it each winter, well apparently they can still have good crops of peaches. i think some of the sprays are not quite as bad as they could be, there are different ones, some using copper and ??

i will be curious to see if anyone here has tips, ideas or thoughts on this.
 
George Hayduke
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My peach trees tend to drop leaves from a fungus in the mid to late summer. I just let them do it and don't treat for the fungus. In the spring the leaves come out healthy and stay healthy long enough to produce a crop of peaches.
 
John Wolfram
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Location: Lafayette, Indiana
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The "organic" way of dealing with peach leaf curl is by applying Bordeaux Mixture which is a combination of copper sulphate and hydrated lime. Unfortunately, the treatment for peach leaf curl is applied in the winter while the trees are still dormant, so you've missed your chance for this year, but there's always next year.

 
Bryant RedHawk
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Location: Vilonia, Arkansas - Zone 7B/8A stoney, sandy loam soil pH 6.5
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The first thing you need to know about this disease is the way it spreads.

T. deformans does not produce fruiting bodies. It forms a single layer of asci (sac-like structure that contain sexual spores) that break through the cuticle to the surface of the discolored and distorted leaf areas (Broome and Ingels, 2011).
It is sometimes visible as a dusty cover on the leaves. The spores are released and are blown to the bark of trees where they survive during the summer. The sexual spores eventually germinate and produce blastospores. The blastospores multiply by budding (“sprouting” a new spore directly from the older spore) and are washed onto new emerging leaves in the spring.
Symptoms usually appear two weeks after infection occurred. The fungus survives with blastospores on the bark of peach trees and near buds.
During wet weather the spores are washed onto emerging leaves. The spores germinate and penetrate the leaves.
The fungus grows between the cells and induces the distorted blister-like deformation of leaf and young fruit tissue by releasing hormones such as cytokinins and auxins that lead to increased plant cell division and enlargement of plant cells.
The increased amount of cytokinins results in the plant’s increased transport of nutrients to the infected tissue providing more food for the fungus.

Spores produced on the leaf surface by the fungus are
washed or wind blown onto peach twigs and buds.
They remain lodged in bud scales or crevices in the
bark throughout the summer and following winter.
These spores germinate during periods of frequent
rain as the buds open in the spring. If rain does not
occur at this time, the spores remain inactive and
little or no infection occurs.

Only juvenile plant tissues are susceptible to
infection, so if no spore germination occurs at bud
break, then little damage results for that year. Spores
are capable of producing secondary spores known as
bud conidia during periods of wet, cool weather.
Both spore types can remain inactive for several years
on the peach tree until conditions are right for
infection to occur. This explains why peach leaf curl
can periodically cause severe defoliation even though
it was not noticed the previous growing season.
Peach leaf curl can be managed by a single, dormant
application of a registered fungicide. In the home
orchard, some registered products may be labeled for
managing the disease or simply for suppression.

Copper containing treatments are the most effective at the proper (fall) time of year.
Once infection has begun, treatments are ineffective.
This means you must be timely in your application of the preventative sprays.

This Fungi may be pH sensitive, no study has been done on this possibility so it is open to experimentation at this point.
Conditions (atmospheric and nutritional) must be right for the infection to occur.
Interruption of the cycle is the purpose of the sprays now in use, other methods of interruption should work just as well.

Since the conditions for bloom are wet and cool it could be contained by altering the condition if possible.
Fans to dry the tree bark and or artificial heat might create the wrong conditions but would be nearly impossible to implement.

One thing that might work, other than using a chemical spray, would be to give the tree bark a wash in the fall after leaf drop.
If the solution used has a pH the fungi can not tolerate and a wetting agent (soap) it very possibly could remove the spores thus preventing a new spring outbreak.

I am in the process of proposing a study along this method to a local university, since my state is one of the larger peach producers in the USA, I have a fair probability to get a grant to do this study.
If I get the grant, I will post procedures used and results found here.
Anyone interested in this can contact me via pm for more timely updates once I start the study.
I will be using three orchards in different parts of the state, plus a control orchard that will continue to use their present techniques.

For now the best method for control is a pre spring spraying with Bordeaux mix.

removal of the infected leaves and bagging them before the asci can break and spread the spores might be of help but so far no evidence of this being effective has been reported.


 
leila hamaya
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Location: northern northern california
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yeah, thats basically what i thought. people that i know, who usually will not spray any cides on anything, regularly spray their peach trees each year.

i was surprised when one of my friends told me she sprays her peach trees every year, she is definitely doing "better than organic" ....but that was before i realized how every tree in this area has this. i only have a few small peach trees, although they are getting bigger now at 2 years old. from starting a lot of seed last winter, i got about 30 young peach trees this spring. it sucks that it seems inevitable that they get this. really makes me want to get the resistant varieties.

she also told me that even if someone did manage to completely get rid of it, and not just have it go dormant, but actually get rid of it, that the forest and conifers carry the fungus. so , in her opinion anyway, even if someone could get rid of it here, it would just come back.

One thing that might work, other than using a chemical spray, would be to give the tree bark a wash in the fall after leaf drop.
If the solution used has a pH the fungi can not tolerate and a wetting agent (soap) it very possibly could remove the spores thus preventing a new spring outbreak.


this is also what i was thinking about, if this would work...or removing all the infecting leaves and burning them....also jojoba oil. jojoba oil is supposed to be good for powdery mildew, because it coats the stems and leaves, and basically suffocates the spores so they cant spread. i was wondering if there might be an oil treatment anyway. i did read something yesterday about using some oil with the spray, which was supposed to make it stay on longer. but maybe using a heavier oil, or soap/oil + ? , might work....

wikipedia (Leaf_curl) surprised me with having a pretty good write up on this and suggesting this treatment:
The most successful means of treating leaf curl organically is spraying with a Trichoderma mix, which is a natural organic fungus which feeds on the other fungus. Whereas copper applications often defoliates the tree, Trichoderma will only attack the area where the leaf curl is on the leaf, the remaining section remains intact and continues to grow. Regular applications of Trichoderma can eliminate leaf curl completely. Trichoderma should be applied at leaf burst and then 2 or 3 times through the season. However as a living organic substance Trichoderma cannot be applied in conjunction with chemical applications.[citation needed]


this is also an interesting idea:
The traditional gardener's method[6] is to plant peach trees against a house wall under an overhanging roof, possibly covered by a mat during the winter, to keep winter rain from the buds before they burst (and incidentally to delay blossoming until spring frosts are over), until the temperature exceeds 16 °C (61 °F) in the spring, deactivating the fungus
.
 
Patrick Mann
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Location: Seattle, WA, USA
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Here in the PNW I've seen a few cases where folks had built a (transparent or temporary) shed roof over their peach tree to keep it dry during the critical period.

My tree gets curl, but so far it's not been very severe. I remove all affected leaves, prune for light and air penetration, and apply compost to help it recover.
 
leila hamaya
pollinator
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Location: northern northern california
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George Hayduke wrote:My peach trees tend to drop leaves from a fungus in the mid to late summer. I just let them do it and don't treat for the fungus. In the spring the leaves come out healthy and stay healthy long enough to produce a crop of peaches.


this sounds like it could be something else? or maybe it is the same. with the leaf curl the early leaves in spring look freaky, then they fall off, and more normal looking leaves come in. i think it will still produce peaches, but not that many.

i suppose it could have some appeal to just do nothing, if that works for you, then great. but i would think it will get worse and worse each year and then eventually not be producing peaches ? this is a guess, idk for sure...
 
Bryant RedHawk
gardener
Posts: 1978
Location: Vilonia, Arkansas - Zone 7B/8A stoney, sandy loam soil pH 6.5
151
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hau, Leila, T. deformans indeed is omnipresent, to eradicate it in any part of the country would create expenditures along the lines of the USA National Debt, so that is out of the question.

In order for leaf removal to work you have to start immediately upon first discovery (even then you are most likely to late to stop the fungus that year), this would slow the spread down but not halt it completely.

Neem oil would perhaps be better than jojoba oil but the desire is to remove the spores, when they are on tree trunks they are dormant and do not respire so trying to suffocate them would be a moot point.

The fungi actually reproduces in three stages, so to really have an effect you need to stop it at the beginning stage, washing it off the tree trunks in winter and stopping it from blooming in the wet spring is going to be key to control.
The reason copper compounds work is that the copper poisons the spores and a kill is the result.

Yes, Trichoderma can feed on T. deformans but the problem there is that once leaves are infected, the fungus has spread to all the unopened leaf buds already and is sitting there, dormant, waiting for the correct conditions to occur again.
Applying Trichoderma will set up attack of only the current infection. It would need to be reapplied everytime a new infection occurred.

This is what Gary E. Harman of Cornell University NYSAES has found.
" Trichoderma spp. are fungi that are present in substantial numbers in nearly all agricultural soils and in other environments such as decaying wood.
Among their other activities, they grow tropically toward hyphae of other fungi, coil about them in a lectin-mediated reaction, and degrade cell walls of the target fungi.
This process (mycoparastitism) limits growth and activity of plant pathogenic fungi.
In addition to, or sometimes in conjunction with mycoparasitism, individual strains may produce antibiotics.
However, numbers and the physiological attributes of wild strains are not sufficient for highly effective control of plant diseases.
The antifungal abilities of these beneficial microbes have been known since the 1930s, and there have been extensive efforts to use them for plant disease control since then.
However, they are only now beginning to be used commercially.

However, development of biocontrol systems has only begun when an effective strain is identified.
In our research, we have used only T. harzianum strain 1295-22 and T. virens strain 41 in our research for the past decade.
The other components of biocontrol systems are of critical importance and require a great deal of detailed research. "

Once again it would seem that who ever put the information on Wikipedia did not fully research before making their submission. I have found many false or un researched conclusions on Wikipedia over the years.

The mention of copper applications defoliating trees is actually a misnomer since that would be an indicator that the spray was applied far to late to have the desired effect.

The traditional method mentioned is great for home owners with only a few trees. I am working on solutions for the orchard grower.
It is impractical to build roofs over 100 acres of peach trees, they would need to be put up and taken down every year, given the fickleness of weather patterns, it could be a lot of effort and expense for naught.
 
leila hamaya
pollinator
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Location: northern northern california
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interesting, i will stew on that information.
i wonder if a treatment when my peach trees are so young would do anything? they do not, so far have any problems.

and, is it correct to say its implied that beneficial microbes, IMO, wood chip mulch, and mycorrhizal activity could have some effect on this?

i suppose i was suggesting coating the trunk and branches with jojoba (or neem, does seem like a better one) oil, right before bud break? here, thats late winter.
i would gather people have been trying to figure this out for a long time, and that seems too simple, but sometimes people miss the simple.
 
Bryant RedHawk
gardener
Posts: 1978
Location: Vilonia, Arkansas - Zone 7B/8A stoney, sandy loam soil pH 6.5
151
chicken dog forest garden hugelkultur hunting toxin-ectomy
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My first rule of gardening would apply to your young orchard, If it doesn't have a problem, don't treat it like it does have a problem.

My own orchard is full of mycorrhizal fungi, every tree gets a dose at planting time and another dose every month for the first year. I have not noted any problems with pear, plum, fig, or the mulberries.
When I plant our peach trees, next month they will be receiving the same dosing as those already planted.
I am fully vested in mycorrhizal fungi use, it works on everything I have used it on. You can clean up water as well as soils, cultivars grow far better with more nutrition value. I have not found one thing that doesn't benefit through proper inoculation with mycorrhizal fungi.

I would use the oil on the bark before winter leaf drop instead of just before bud break. Neem oil has some anti fungal, anti bacterial properties.
The T. deformans spores like to lodge in crevasses found in barks and around new leaf buds.
Filling these spaces with Neem oil seems like a good preventative measure.
This way the oil may bind up any spores looking for a place to over winter which could allow them to be washed off easily any time, including in the early spring.

Actually is appears that significant amounts of research have only been happening since the early 1970's. Prior to that most of the research was focused on stopping disease instead of prevention.
When I was in college one of my professors was starting a study on fruit tree diseases with the hopes of finding real cures or treatments that would last longer than one season.
I was one of his student teachers and we worked on several projects over the two year period before I finished my masters.
We found some successes but mostly the slant was on "chemical treatments" (copper isotopes). His study went on for ten more years after I left school.
 
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