My golden delicious apple tree is ailing - Ask Extension
My apple tree is sick. Pictures are attached. A fungus?
The tree was delayed in leafing out and had no blossoms this year. I watered it, remov...
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My golden delicious apple tree is ailing #656790
Asked June 27, 2020, 1:32 PM EDT
My apple tree is sick. Pictures are attached. A fungus?
The tree was delayed in leafing out and had no blossoms this year. I watered it, removed mulch from around the trunk and waited for recovery, which didn't happen. It was fine last year - produced 30 golf ball size apples with normal leaves. Its pollination partner, a honey crisp, is normal.
A diagnosis and/or suggestions for treatment are really appreciated.
- Donna Duncan
El Paso County Colorado
Expert Response
Hello Donna,
thank you for your question regarding your apple tree. As you probably have seen all over town, this past winter has caused a lot of damage to all kinds of vegetation.
I'm glad to hear your "honeycrisp" apple tree is well.
I believe that you might have a couple things going on with your apple tree. The delay in your trees budding this year is contributed to the winter damage that started in October with a sudden drop in temperatures and again in April. We have seen the damage on evergreen starting in winter and now a lot of deciduous vegetation is showing damage too. Ash trees, maples lilacs etc, all kinds of bushes and trees are slow in budding or not budding at all. I think that is the reason that your tree is delayed.
If the tree was trying to recover from this past winter when we were hit with another freeze in April, which is probably responsible for "no flowers" this year.
With all this stress your apple is very susceptible for disease.
In the last link below you can read about diseases that effect apple trees (fireblight, powdery mildew etc.).I appreciate you sending pictures along with your question, unfortunately I am only able to magnify the one with the single leaf.
I don't believe that it is fireblight at this time, the fungus would attack your apple tree at the time of bloom (which your tree didnt have) and it would show a bunch of leaves brown and dry. I also thought of Powdery Mildew when I saw the picture of the single leaf, but the grey fuzzy coating would be all over leaves and stems. I am not able to magnify the other leaves to inspect further.
Just recently CSU has put out information of a recent discovery of fruittree leafrollers being a nuisance this year:
"The FRUITTREE LEAFROLLER overwinters as eggs within a flat gray egg mass on twigs. Eggs hatch in spring shortly after leaves have emerged. Young larvae tie up leaves with webbing and feed inside this shelter. When mature, larvae pupate in the rolled leaf and adult moths appear two weeks later to lay eggs. There is one generation per year. Control: Leafroller outbreaks are often highly sporadic, and numerous natural controls usually prevent high, damaging populations. Supplemental controls are rarely needed for plant protection. Horticultural oils applied during the dormant season are effective at controlling overwintering egg stages of this insect. Applications should target the twigs, where egg masses are laid."
https://wiki.bugwood.org/HPIPM:Leafrollers
http://treefruit.wsu.edu/crop-protection/opm/leafrollers/
If you can, inspect the rolled up leaves and see if you can find larvae/caterpillars growing inside, or inspect your leaves for further grey fuzzy coating for Powdery Mildew.
I attached a link for future reference that talks about things to look out for and prevent on apple trees.
https://extension.colostate.edu/topic-areas/yard-garden/backyard-orchard-apples-and-pears-2-800/ apple diseases
I believe that your apple tree is struggling to recover fromthis past winter and there is a chance that it might have insect damage by the fruittree leafroller which could be treated, as mentioned in above links. The apple tree might take a couple of years to recover just from the winter hit.
thank you for your question regarding your apple tree. As you probably have seen all over town, this past winter has caused a lot of damage to all kinds of vegetation.
I'm glad to hear your "honeycrisp" apple tree is well.
I believe that you might have a couple things going on with your apple tree. The delay in your trees budding this year is contributed to the winter damage that started in October with a sudden drop in temperatures and again in April. We have seen the damage on evergreen starting in winter and now a lot of deciduous vegetation is showing damage too. Ash trees, maples lilacs etc, all kinds of bushes and trees are slow in budding or not budding at all. I think that is the reason that your tree is delayed.
If the tree was trying to recover from this past winter when we were hit with another freeze in April, which is probably responsible for "no flowers" this year.
With all this stress your apple is very susceptible for disease.
In the last link below you can read about diseases that effect apple trees (fireblight, powdery mildew etc.).I appreciate you sending pictures along with your question, unfortunately I am only able to magnify the one with the single leaf.
I don't believe that it is fireblight at this time, the fungus would attack your apple tree at the time of bloom (which your tree didnt have) and it would show a bunch of leaves brown and dry. I also thought of Powdery Mildew when I saw the picture of the single leaf, but the grey fuzzy coating would be all over leaves and stems. I am not able to magnify the other leaves to inspect further.
Just recently CSU has put out information of a recent discovery of fruittree leafrollers being a nuisance this year:
"The FRUITTREE LEAFROLLER overwinters as eggs within a flat gray egg mass on twigs. Eggs hatch in spring shortly after leaves have emerged. Young larvae tie up leaves with webbing and feed inside this shelter. When mature, larvae pupate in the rolled leaf and adult moths appear two weeks later to lay eggs. There is one generation per year. Control: Leafroller outbreaks are often highly sporadic, and numerous natural controls usually prevent high, damaging populations. Supplemental controls are rarely needed for plant protection. Horticultural oils applied during the dormant season are effective at controlling overwintering egg stages of this insect. Applications should target the twigs, where egg masses are laid."
https://wiki.bugwood.org/HPIPM:Leafrollers
http://treefruit.wsu.edu/crop-protection/opm/leafrollers/
If you can, inspect the rolled up leaves and see if you can find larvae/caterpillars growing inside, or inspect your leaves for further grey fuzzy coating for Powdery Mildew.
I attached a link for future reference that talks about things to look out for and prevent on apple trees.
https://extension.colostate.edu/topic-areas/yard-garden/backyard-orchard-apples-and-pears-2-800/ apple diseases
I believe that your apple tree is struggling to recover fromthis past winter and there is a chance that it might have insect damage by the fruittree leafroller which could be treated, as mentioned in above links. The apple tree might take a couple of years to recover just from the winter hit.
Dear Heike,
Thank you for your detailed response to my question about my golden delicious apple tree's curled and sparse leaves. I see no signs of the leafrollers, no chewed leaves, no browning or spotting. Your analysis that it made a weak attempt to recover from the two late freezes seems the likely explanation. However, I researched the internet for apple trees that grow in zone 4 before the purchase. It gets fertilized, mulched and netted. Should it come back healthy/normal next year?
Thank you again,
- Donna Duncan
Hi, Donna
I am following up on Heike's response. Even though the trees are hardy to zone 4, they can still be strongly affected by sudden freezes, because they don't have time to harden off. In this case, it was a double whammy, because the tree was caught off guard (so to speak) in the fall, and then was hit again in the spring when it was beginning to bud out.
The leaf curl makes me wonder if the tree is getting enough water. Is it on the same irrigation system/schedule as the honey crisp? Is it on a bit of a slope or higher ground, and therefore better drained?
Regardless, make sure to give it a little extra water this year. If the tree has enough resources, it will make a good recovery, but if it doesn't leaf out well next year, it may not make it.
I am following up on Heike's response. Even though the trees are hardy to zone 4, they can still be strongly affected by sudden freezes, because they don't have time to harden off. In this case, it was a double whammy, because the tree was caught off guard (so to speak) in the fall, and then was hit again in the spring when it was beginning to bud out.
The leaf curl makes me wonder if the tree is getting enough water. Is it on the same irrigation system/schedule as the honey crisp? Is it on a bit of a slope or higher ground, and therefore better drained?
Regardless, make sure to give it a little extra water this year. If the tree has enough resources, it will make a good recovery, but if it doesn't leaf out well next year, it may not make it.
