Where are you? I doubt your problem is related to spraying and if it is you need to know what is afflicting a plant to have any business spraying it. Apricots are fragile trees but one would need to know your zone to make any recomendations.

I'm in California near San Jose, prime apricot country. Brown rot is the most common disease here. Gumosis (according to the nursery person I consulted) is a symptom, not a disease. It is consistent with brown rot. We get lots and lots of weeping sap forming amber lumps, deep splits in the bark that are slow to heal, and twigs that blacken and die. We do get some good fruit but it all drops to the ground in a couple of days. I have never known whether this is a characteristic of this particular variety, or whether it is a symptom. Spraying with copper is recommended by the UC Davis home orchard website. Normally I would spray in fall and spring, but when I saw more lumps of weeping sap and had some leftover copper in my tank from spraying my roses, I did so today.

My zone is listed above with my name, USDA 9, Sunset 16.

Rosefolly

Rosefolly:

1. When a backyard grower such as myself offers advice, it is most often limited to our personal experience, without the benefits of scientific methods employed by university studies. Some of these personal observations may nevertheless have some validity, though another risk is to apply those observations across different climates.

2. With those cautions in mind, I can tell you that of the around 10 different varieties of apricot I have tried to grow, (some of which have been gone for years), the most disease resistant, productive, and otherwise reliable cultivar I have grown is Tomcot. My early experiments with West Coast varieties such as Tilton, Wilson, and Hungarian Rose were all failures, with early onset of disease, low fruit set, and nearly 100% fruit cracking before maturity. I still have two, fully mature 14-year Tomcot trees with no sign of bacterial or fungal disease, although I also have a younger Puget Gold and a Goldcot out there. I keep nursing them along, and they don't show disease problem yet either, but Tomcot has already shown me it can survive the long haul in a Northern Virginia climate that has all the fruit tree diseases known to mankind. Tomcot, like Puget Gold, was introduced by the Washington State Univ. development program. I am pretty sure that Goldkist, like Goldcot, is from Michigan State. It is not clear to me why an apricot like Tomcot from the PNW does so well here, but it does.

3. To say that Gummosis is a symptom not a disease is wordplay. Symptoms do not occur without an underlying disease, although diseases can exist without exhibiting symptoms. Gummosis is the visual indicator of infection by any of a number of fungal organisms, and I would give you their Latin names if I had them handy. Bacterial canker is a disease of different origin, which exhibits very similar symptoms -- sap leakage and limb dieback. Perhaps a fruit tree scientist could tell you the difference between the two by looking, but I don't think I could. I believe, but cannot swear, that most of my problems here have been bacterial in origin. When you describe the deep splits in your bark, that leads me to believe your problems may be bacterial canker as well, since Gummosis usually does not reach such a severe stage.

4. The best treatment I know of for either of these diseases is more than one strong copper application during the dormant season. I do the first in early winter; the second just around bud break. I am convinced that the strength of the copper application, as well as full coverage, are the keys to staving off disease on stone fruits. I use Kocide 2000 (copper hydroxide), and apply it at a mixing rate of one full ounce (around 3 tablespoons) per gallon. If I were using anything weaker than Kocide, I would adjust the mixing rate accordingly. I do not use Kocide at all during the growing season, since I have observed leaf damage even at greatly reduced mixing rates.

5. Obviously, there are other things you can do to keep a stone fruit tree healthy, such as careful orchard cleanup, and prompt removal of any limbs showing signs of canker or sap leakage. (Your mushrooms, BTW, are growing on necrotic wood or roots, and as such are a symptom only of dead wood.)
But if you live in an area where there are many apricot trees around, and some of them are unsprayed and infected, it may always be difficult to prevent infection on your trees, whatever the variety.

6. Your tree, as you describe it, might as well come out, and the sooner the better. Trees with widespread infections do not recover, and can spread their problems to neighboring trees. The key to dealing with bacterial and fungal infections is prevention, not cure. If you can find a Tomcot to buy, try it and we can compare notes in about 10 years. By that time I will be a super-geezer or nothing at all. I should also mention, BTW, that Tomcot is a delicious apricot, fully freestone and easy to freeze or dry, as well as being the earliest ripening cultivar I have seen.

Don Yellman, Great Falls, VA

Jellyman:

Thank you for your time in conveying to us, the readers of this forum, the benefit of your experience and wisdom. Your reply to Rosefolly about apricots is just so articulate and cogent in addition to it's being accurate and so useful.

However, may I, as a junior geezer, hazard a difference of opinion with the master geezer? Eventually, when part of you is compost, much of your knowledge will still reside on this forum as well as my hard drive. Further repositories will be in the minds of the readers of this forum who will, in turn, be passing it on. This chain will continue for a long time. And the substance of the chain-repository is how to make food -- not something to be casually dissmissed by the inhabitants of our planet. Certainly all this is NOT "nothing at all."

Tony

Jellyman, I am going to follow your advice and remove the tree. I do agree that there is little that can be done to save it at this point. I did some more reading and agree that the symptoms sound more like bacterial canker than they do brown rot. I appreciate you taking the time to answer my question so thoroughly. Silicon Valley where I live is former orchard territory, plums, cherries, and apricots, so any disease that afflicts those trees is probably all around us.

Thanks again.

Rosefolly

Hi Rosefolly:
I am living 75 miles away in Carmel Valley and have the same problem with gummmosis-however in my case it has been analyzed as Eutypa dieback. I think my mistake was not sanitizing my pruners between trees, as well as not pruning in the summer since the fungus is spread with the rains and prune cuts. The UC website has a lot of information. Anyway the Autumn Royals and Blenheims are coming out and being replaced with nectarines.
Good Luck
Joe

Hi Rosefolly, San Jose used to be prime apricot country, but I think most that has been paved over. I don't think one can say this is caused by brown rot. Gumosis is caused by disease, but there are a number of different things that can cause gumosis. Two things I would do would be to cut off the diseased wood. Second I would make sure to prune in late fall, either August or September.

I used to grow Apricots commercially near Patterson and we used Rovlar commerically to control brown rot. Rovlar used to produce a small bag that was sold over the counter to home gardeners. They discontiued that years ago but who knows, maybe you'll find it again. Brown rot starts at the bloom stages and it is critical to get the appropriate fungicides on during this period if brown rot has been a problem or if you have experienced wet weather during this period.

Coppre sprays like Koicide can ruin apricot blossoms if you are not careful. There are other garden fungicides sold over the counter that are supposed to control brown rot, how effective those are I wouldn't know.

When I was a boy in southern CA almost 50 years ago, we had an apricot tree that was my first experience with a fruit tree. The tree has never been sprayed and thrives to this day (my 86 year old dad still owns the property). I still love apricot trees but they are much more difficult in zone 6 northeastern NY. I use Indar fungicide with great success to control brown rot. 2 sprays a season are usually adequate.

I doubt that the problem with your apricot was the disease susceptibility of the variety. My neglected apricot was not unusual, there were many all over my region and yours that thrive without chemical input.

I suspect your problem is in the soil. Apricots need a rich, light, well-drained soil to be strong. Often diseases are in fact a symtom and not a cause and even if my guess doesn't hit the mark, I bet your problem is environmental and most likely in the soil. Check soil pH etc.

Rosefolly,

I would make one California-specific emendation to Jellyman's excellent and comprehensive post: in many locations, Armillaria fungus can and will attack living plant tissue. You should be able to find plenty of information on this disease by "googling" the terms "armillaria root rot" and "oak root fungus".

You mention "a huge eruption of mushrooms coming from the (tree) base", so it strikes me that your plant may be dealing with this fungal problem as well. If so, there's not a darn thing you can do about it. (I would agree that removing the tree is probably a good idea in any case -- it sounds like it is old and declining, perhaps from multiple causes.)

If you do have Armillaria in your soil, you will need to plant a replacement tree with a resistant rootstock. (If such a thing exists; I'm not certain whether there are any Armillaria-resistant rootstocks for stone fruits.)

Mushrooms in the soil is not useful as a specific diagnostic tool. Fungus will always feast on dying roots whatever the cause of decline.

Well, the tree is gone. I did wonder about armillaria myself, but the master gardener I called said just what harvestman said, that it could just as easily be dying roots. I am sad to say it was actually quite a young tree, only seven years old. As for resistant rootstocks, both Marianna 26-24 and Myrobalan 29C show some resistance to armillaria. I am quoting from the Bay Laurel Nursery catalog here.

In any case we will replace the tree with another apricot, and in quite a different part of the garden. We've decided to do a bit more research before selecting a cultivar. At this point we are considering Harcot and Royal Rosa, both recommended by that same master gardener. We are attending a seminar on fruit tree varieties for our area this weekend, and hope to get more information there.

BTW, the MG told us that based solely on description, it could as easily be Eutypa dieback as bacterial canker. Apparently the two look much alike to the novice (me). I don't know much about this, but boy I am learning as fast as I can.

This is more than a general "mushrooms in the soil" issue. For specific diagnostic information, here is the following link.

Here is a link that might be useful: UC IPM On-line -- Armillaria Root Rot in Apricots

Rosefolly,

Ah, you posted just as I was replying. Yes, there certainly could be multiple issues going on. If you do have Armillaria in your soil, you should choose a resistant rootstock for your replacement plant, which was kind of my point in mentioning it in the first place -- but you've already done your research!

By the way, "Blenheim" remains the gold-standard for flavor, and you should be able to grow it just fine in San Jose. It is not particularly resistant to brown rot, so you would have to spray. (If I don't spray, the brown rot pathogen starts to get out of control pretty quickly in wet years.)

You might want to be sure if you have Oak Root Rot or not so you can plan for it, if that is the problem. The characteristic looking mushrooms are a good symptom. I have it in an area around my oak tree, and grow plants in large pots there. Drainage, air exposure of upper roots, is everything with this disease. Planting four different cultivars in a raised bed would let you know in a few years which were the most disease resistant to your particular soil conditions- a survival of the fittest, as well as giving you an apricot harvest spread out over time, and not a big glut to deal with in two weeks. A Tomcot, Blenheim, Moorpark, and Autumn Glow planting would give you apricots all summer. Be careful to sanitize you pruners, as JoeGrower suggests, and to dormant spray. Even the most disease resistant varieties need a little help from their friends now and then.

rosefolly,

Last year I planted several plums grown by Dave Wilson Nursery in California. The trees also came with a rootstock label that says "MYRO 29 C ROOTSTOCK. Shallow but vigorous root system tolerates wet soils, is immune to root knot nematodes and has some resistance to Oak root fungus." I was glad to find out why I never heard of these diseases. Root knot nematodes are a southern pest and Oak root fungus is a West coast disease. Our Gypsy Moths here leave us only the stems.

http://groups.ucanr.org/slomg/documents/Pests_&_Diseases3863.htm

I am surprised that brown rot would be a big issue in Sacremento. As I said earlier, I have seen many succesful apricot trees bear fruit in Southern Ca without spray. The one at my fathers house has born fruit for about 45 years in a row without a spot of brown rot. If you were right on the ocean it would be another matter though in S. CA unsprayed apricots do well by the beach.

The Harrow Station where Harcot comes from looks at brown rot as an issue and strives for resistance. Harcot is one of the resistant ones.

You never responded to my suggestion that the problem may be environmental. When I was in Hort-shool we use to say that the pathologist will always find the pathogen but the horticulturist will find the cause. In many years of managing plants I have never rescued a plant with information I've gleaned from a pathologist though I've gone their for advice several times. Maybe you're confident that the soil conditions are optimal and your tree must have suffered from something more exotic than the usual horticultural problems.

Harcot is indeed resistant here in Davis. It is one of the very few apricots that bore fruits when we had the worst period of rainy days during the bloom time a couple of years ago. Harcot is also resistant to late frosts, usually by doing several batches of bloom, could be just my tree. Harcot is a lot better tasting than Tomcot, but I agree that Tomcot is already excellent tasting. The taste of Harcot is like a sweet yellow nectarine with very mild acid, truly outstanding.

Major problem though for people in San Jose or the Bay Area is that this is one of those high chill apricots, perhaps requiring 700 hours or more, so I could not recommend this for the Bay Area and other low chill areas.

In the northeast we always have rain during bloom time but I guess our cooler weather is less conducive to blossum blight (brown rot on blossums) as I've yet to encounter it. It is our humidity as stonefruit ripens that tends to often rot stonefruit. Because apricots ripen before the humidity really sets in they are amongst the least brown rot susceptible though some varieties get scabby.

The brown rot pathogen is easily controlled with either Pristine or Indar and a single spray would control blossum blight in any conditions, I believe.

The original posting suggested not that the tree was losing fruit to brown rot but that it was killing the tree, so all this discussion may not even apply as this diagnosis may well be wrong to begin with. In my experience, brown rot ony affects the health of a tree with inadequate vigor to begin with. Beyond damage to the fruit none of the trees I manage has ever been seriously affected by it except seriously neglected trees competing with weeds in poor conditions.

I realize that I'm a long way from central CA but my climate is much more conducive to this fungus than inland CA which is pracitically a desert during most of the growing season. Is anyone posting from that area speaking from a great deal of hands on experience? This would be instructive.

I thought the tree is already to be replaced as the discussion ensued, if so, what cultivars would be better, given the history. Tomcot would be the best suited, based on Don Yellman's excellent advice. Harcot would also be nice, but recalling that the place is around the Bay Area, it would not get enough chilling hours in most years.

We are 12 miles west of the Sacramento Capitol as the crow flies. In our area a couple of years ago, during prolonged low intensity rains around bloom time, there were severe brown rot, blossom blight on apricots. Peaches also got the blight and rot aside from peach leaf curl. Fruit sets were generally poor. During those times, Tomcot, Goldkist, Royal Rosa, Harcot apricots fruited adequately without needing to thin out (that means just adequate fruits).

Last year, we had relatively very dry spell during the bloom, and almost all stone fruits whose diseases did not get deeper into the tree, they have limb breaking yields.

Those are a few observations from around the neighborhood who seldom spray their trees. Oftentimes, it is useless to spray your trees in an urban setting, because of the neighbors. And even if you did get their permissions, not everyone will spray at the same time. So you will always have a reservoir of diseases and their vectors. Often hobbyists have a plethora of cultivars in close proximity of each other and not big blocks of monocultured trees. Planting distances of trees are designed for machineries to pass through in commercial orchards and these spacings are never applicable for a city backyard in prime costing land.

Commercial growers and home hobbyists have different objectives in raising fruit trees or plants in general and have dramatically different environments in which they operate. I take the observations and experimentations of hobbyists and home growers with proper context and value them much better than the standard methods meant for commercial growers. One has to consider these primary differences when discussing various issues.

When I moved into my house in 1981, there were two large, fruiting apricot trees, along with other fruit trees. I tried to add more. One at a time, certain trees would get sick and die, including one of the mature apricots. The more I watered, fertilized and cared for them, the faster they died. A few rose bushes did the same. Other trees, roses thrived, for no apparent reason. The problem seemed to be localized in one section of the yard. I contacted a local aggie college by email, described the problem, and the nicest instructor did a home visit, collected samples, studied them at his lab. He made a diagnosis of oak root rot. He was able to give me a few suggestions about how to deal with it, and I did some research on my own. Im so grateful to him for taking samples and giving the correct diagnosis. Plant diseases can be as specific as human diseases, and often there is a specific cure as well. But a correct diagnosis is essential.
The mature apricot dying was a relief. Both trees would have a heavy glut of fruit right when my job was crazy busy, 12 hour days, and I could only watch a mound of rotting fruit build up on the ground by flashlight under both trees, with so many wasps the kids were afraid to play in the back yard. I swore I would never let that happen again, as much as I valued my fruit orchard.
The second mature apricot died last year, amid a flourish of Armillaria mushroom caps around the base. The new four trees in one box of healthy apricot/aprium trees is thriving, as are my three other "four boxes". There is almost always something fresh to nibble on from the orchard throughout the year, with extras to share.

I grew apricots commercially in the CA Central Valley for years and have some experience with brown rot. Normal winter years was not a problem as we sprayed Rovral during the bloom stage. There was one year we had a brown rot problem which happened during the El Nino years. We had non-stop rains from February though April and the sprays were not enough. The trees looked fine and the fruit looked okay until it hit the fruit bins where they rotted away.

I have never seen brown rot affect anything other than the fruit. As far as what is going on with this poster's tree, I think there are two different things going on. There maybe something in the soil. Sometimes we just lose trees. Happens to everyone. As far as watering is concerned, Apricot trees in general can tolerate wet soils as well as other stone fruits. It depends on the rootstock. Nemaguard is somewhat sensitive, but we had 29C rootstock and we used to flood irrigate the apricot orchard and there was one area that did not drain well. There would be standing water there for an extended period, same for the winter, and those trees thrived.

Our orchard was planted on previously mixed native forest land cleared and planted 50 years ago. Oak root fungus is everywhere in our soil. We have to dry farm our orchard or the fungus goes into rampant summer time growth and will kill our trees, even those pro ported to be "resistant". Al

According to UC Agricultural Extension (http://ipm.ucanr.edu/PMG/r5100911.html), Eutypa is a fungus that causes gumosis. Eutypa is spread by moisture--rain, fog, sprinklers. For that reason, you should NEVER prune apricots in the rainy season, because the fungus spores will enter the cuts. You should never put sealer over the cuts either, and let pruning cuts heal naturally. Fungicide can be applied in winter if you really must prune in winter. It is preferable to prune apricots, grapes, plums, and cherries in summer - July/August, after harvest.