I have been to every French website and they all say the same thing about the heat this summer. The Gummosis is horrible, there is nothing we can do but leave it alone. All of the stonefruit trunks and branches look as if they are dotted with clear rain drops that don’t move. The heat is what is stressing the trees. The plums are starting to shrivel and atrophy. By the end of August it will be over, perhaps sooner as July is this month of heat this year. Horrible to watch my trees go through this. My apples and citrus are just fine. The apricots were excellent again, and the peaches are still rock hard. The mirabelles are troubled, but hanging in. No pun intended.
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Sorry to hear that. I always have a lot of that on my older peach trees. Probably a regular Maryland summer is like the heat wave there? Its in the 90s nearly every day here for several weeks.
Scott, I would take 90! We have had 101-104 degrees five days at a time. The trees are terribly stressed. Worse than last year. Even though my trees are at fruit bearing age when purchased, , I have only had them for four years. Ugh.
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What % has your humidity been, mrsg47 ?
44% or lower. For the south of France close to the Med. that is dry.
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Wow that’s bad! We get lots of 90s but little above 100. Of course we also usually have horrible humidity, much worse than 40%.
Hi Mrs. Gibson.
Gummosis is not a disease in itself, it is a physiological syndrome in response to a stress , ( like the fever in humans, it is not a disease in itself, it is a physiological response to a problem).
Not only is it produced by drought, it can also be produced by excess water, a fungus, or a plague, such as the larvae of wood-boring beetles, etc…
In your case , which has proven to be due to drought and excess heat , the choice of rootstock is essential .
I will tell you that I am from the town of Villarrobledo in the region of Castilla La Mancha, and in my town temperatures reach 45° C (113° F), and more, now we are in a heat wave and every day we are between 45 - 46° C, and I tell you this, because tomorrow I am going to show you, a couple of almond tree plantations, without any irrigation, and so you will be able to check how the G xN 15 Garnem rootstock behaves, with the heat and the drought (it doesn’t affect it in the slightest), it is the rootstock that I use for the stone fruit tree.
You who are in France should use GxN 15 Garnem, and stop having these kinds of problems.
When the gummosis occurs, for another reason, it is necessary to give it its corresponding solution.
Regards
Jose
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Hi Mrs. Gibson.
I am going to show you some photographs, of an almond plantation, which is next to my orchard.
This is the third year in the land of these almond trees (when they were planted they would have been about 20 cm).
Wen I got out of my car to take the photos , I almost died, since we had 46° C (115° F) and only 10% relative humidity.
They have never been watered at all, and this year is extremely dry, since it rained almost nothing in spring.
Look how healthy and vigorous these almond trees are, without any irrigation, and in one of the hottest and driest areas of Spain.
Look how the youngest shoots are
There is an almond tree, which has sprouted out a shoot from the rootstock, which is what makes this miracle possible.
The rootsoock is GxN 15 Garnem.
When gummosis appears in the trees, due to excess moisture in the soil, causing root asphyxia, it is necessary to choose a rootstock resistant to asphyxia.
That is, today, choosing the right rootstock, it is very, very difficult for it to appear gummosis in our fruit trees.
Regards
Jose
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Thank you so much. I felt that the heat was a major factor of the stress. I order my trees on line. I am always told the rootstock, but many times I have no choice. All of my trees are also grown in Very, very large pots. I want to see the photographs you are talking about. Thank you for your reply about rootstock.
It is also a very beautiiful tree.
Mrs. Gibson.
If any of your trees have gummosis on these dates, first of all you have to check that your trees are not affected by bighead worm larvae (Capnodis Tenebrionis), since you are in a risk area.
I am going to show you some photographs, but you have to pay close attention to the trunk and primary branches, to detect very small holes.
Damage caused by the Bighead Worm (Capnodis Tenebrionis), which causes gummosis and death of the tree, if measures are not taken:
- This is the beetle in the adult state.
- Deposits eggs near the roots and the larvae penetrate the soil looking for food in the youngest roots, and remain underground for up to 2 years or more, after this period the larvae penetrate the tree through the roots, feeding on its wood, until it comes out making a hole to the outside and goes from its cycle as a larva to that of a beetle and begins the cycle again.
The adult beetle is very easy to eliminate with insecticides such Deltametrin.
Capnodis Tenebrionis larva inside the tree
Holes made by the larvae, when going outside.
If not dealt with promptly, they will severely weaken the tree one year and kill it the next.
When the larvae are in the roots or inside the tree, there is no other remedy than the chemical fight with systemic insecticides, which penetrate all the tissues of the tree.
The only systemic insecticide authorized in the European Union to combat indoor larvae is Acetamiprid (several annual applications must be made (especially after harvest).
Acetamiprid (EPIK trademark, 35 grams of product per hectoliter of water)
Epik
If you notice that your trees do not have any holes, they are suffering stress due to drought and heat stroke and what you should do is preventively spray with a very cheap product, it is called “Natural White” and it is micronized kaolin clay.
This product is applied by foliar fumigation dissolved in water, it reflects the sun’s rays and is absolutely effective in avoiding stress due to heat stroke.
- Natural white
I hope it helps.
Regards
Jose
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Thank you. Just in case I ordered Deltamethrine today.
44% or lower.
I do have a bag of Surround which is the same.
Yes, Mrs. Gibson, it’s hotter than in the fucking Iraq.
Today not even the lizards resist here.
Since it is a heat wave coming from the south, it brings Saharan dust into the atmosphere, generating haze, and it is hellish.
Today we will have reached 45-46°C in my town without any problem (it’s brutal), you can only be inside the house with the air conditioning running.
Surround is the micronized kaolin from the Basf-Agro company (it is very, very good).
Keep in mind that it will prevent dehydration of the leaves due to heat strokes, but if you have the trees without watering and the rootstock is not resistant to drought, your problem will persist.
Pay close attention to small holes in the trunk (bighead larvae).
I make a lot of emphasis, because the south of France is a high risk area for this bad bug.
With Deltametrin it only kills the beetles, to eliminate the larvae inside the wood, several treatments are necessary for two or three years with Acetamiprid (from the egg stage, until the tree worms come out, it can take three years), so there is to treat with Acetamiprid, for several years, to be sure of its eradication, and later, a couple of annual treatments are advised as preventive , and incidentally the aphids and the green mosquito are killed.
Regards
Jose
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Dear José, I checked my trees. I do have black head beetle holes in the trunks of a number of my trees, but not all. I have ordered all of the sprays in the past few days. They should arrive this week. I found little black holes up and down my trunks and some branches. It is making me sick to see this as my trees are only 4 years old. This is the first time for any insect in my potted orchard, except for aphids. One summer aphids almost destroyed an espaliered apple tree.
I am sick over this insect, as I was so excited to live where sprays are not necessary except for canker. Canker was a small issue but existed.
These are just bottles of spray of the two chemicals you suggested. I bought them both. I will follow the instructions. Thank you.
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Dear Jose, can you please tell me the exact name of the beetle making holes in the trunks of my trees. Thank you!
Dear Mrs. Gibson.
I had well-founded suspicions that your gummosis would be due to the big-headed worm.
Its entomological name is:
-Capnodis Tenebrionis
I recommend 3 fighting methods.
- First :
Fight with “systemic” chemical insecticide (penetrates into all organs of the tree).
The application is made in spring (April) and autumn (mid-September), to eliminate adult beetles in spring before they lay their eggs, and in autumn young beetles that have metamorphosed from larvae.
Two treatments are carried out in spring and two in autumn, and the insecticide to apply is this:
- Active materia “Acetamiprid”.
- Trade Mark name “Epik”
It is a " relatively expensive " insecticide , but keep in mind that the dose is 35 grams per hectoliter of water , so with an envelope of 100 grams , you will have enough for several treatments
I’ll give you a link, where you can buy Epik insecticide, in 50-gram sachets, without the need for a phytosanitary applicator card (this format is intended for gardening)
Epik Insecticida sistemico 50 gr - Sipcam gclid=Cj 0KCQjw5f2lBhCkARIsAHeTvlhdzpFgShJOkmJOAFe_Na3b44b5jPgWSKWA6QPTxMyX-divXGKz4WcaArOfEALw_wcB
But you can buy it on eBay.
Keep in mind that it is applied by foliar spraying, and that the dose is 35 grams of powdered insecticide for every 100 liters of water (you already calculate how many liters you may need for foliar application of your trees).
Keep in mind that Epik is the most effective insecticide against aphids, so you can perfectly carry out three treatments per campaign
- Mid April
- Middle of May
- Beginning of September (to kill the young beetles)
-Second:
Application via irrigation of entomopathogenic nematodes ( Steinernema carpocapsae ) .
If you apply this treatment well, there is no living bug left under the ground.
They must make 2 applications each year.
The months in which it can be applied via irrigation are May, June, July, August and September.
Several factors must be taken into account, so that the nematodes settle well in the roots of the tree:
-Water the tree abundantly, one or two days before treatment
- Carry out the treatment at sunset without sun (ultraviolet rays destroy nematodes)
Instructions for use and dose per tree.
This is the product that will arrive at your home refrigerated (it must be kept in the refrigerator until it is applied).
- Capsanem 50
This is more difficult to calculate hahahaha, so it is better to go too far than to fall short.
The package contains 50 million stage 3 nematode larvae (ready for combat).
The dose per tree is between 1 and 3 million nematodes per tree.
It is essential to apply, taking into account that the water where you are going to dilute it for irrigation, has to be at a temperature between 15 and 20 ° C.
It is essential not to stop stirring the water, so that the nematode larvae do not go to the bottom of the container…
- Third :
You are in an area of high risk of big-headed worms (it likes a hot and humid climate) so in my region there is no presence, since the environmental humidity here is almost zero.
And this advice is very good and is used in risk areas.
As you know, bitter almonds contain a toxic compound called amygdalin, which releases cyanide and is deadly to all living things (a human dies from ingesting 30 bitter almonds).
Well, this compound is not only found in the fruit of the bitter almond tree, but also in all its organs (including the roots).
The use of the bitter almond tree as a rootstock is a lethal barrier against any worms that feed on the root or wood of the bitter almond tree.
Be careful, bitter almond trees hybridized with sweet almond trees are not worth it.
If you want bitter almond trees as a rootstock, tell me and I will arrange the shipment from a nursery in Caravaca de la Cruz in Murcia.
Now it’s your turn to ask anything you want.
Regards
Jose
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Forgot to comment.
You can grow any stone fruit using bitter almond tree as rootstock (even cherries), to grow cherry on almond tree, you simply need to make an intermediate graft of Adara plum (I send you cuttings), to make it compatible with cherries
Regards
Jose
Thank you José, they will not ship to me in France. They will only ship to Portugal and Spain. I will try to get it here. Ugh! 
. Its ok. I found another store that has it. It will arrive next week. The rest of the sprays arrive this week! I am all set to conquer the big headed worm!!!