Can't Identify Defect on Growing Haralson Apple - Ask Extension
Hello,
I've been growing apples for many years but I can't identify the defect shown in the attached photos. Details:
1) The defect is on appro...
Knowledgebase
Can't Identify Defect on Growing Haralson Apple #841515
Asked July 19, 2023, 2:22 PM EDT
Hello,
I've been growing apples for many years but I can't identify the defect shown in the attached photos. Details:
1) The defect is on approximately 5% of the apples.
2) The defect is primarily on the ground facing side of the apple (away from the sun).
3) All apples with the defect are misshapen.
4) There are no visible problems inside the apple.
5) The defect seems to develop a crack over time (but not on every apple).
Hope you can help!!
Thank you.
Washington County Minnesota
Expert Response
Hi ,
I think that is apple russet. The skin turns brownish and rough but there is no interior damage.
https://ipm.missouri.edu/MEG/2019/5/russet/
Does the link describe what you are seeing ?
Sally Granath
St. Louis County MG
Hi Sally, thanks for your answer. I'm familiar with russeting but my defect is always present longitudinally from the stem to calyx in varying widths around the growing apple. Apples with this defect are always misshapen (smaller) on the defect side. It's as if the portion of the apple with the defect has stopped growing.
At early thinning time I saw none of it but as the apples are growing I'm seeing more every day. We have had severe drought here until a few days ago, so russeting conditions are not ideal. I see it on my Haralsons and Haralreds and to a lesser extent on my Honeycrisp trees. Only one or two on my State Fairs.
I'll let you know if I ever figure it out. Thanks again.
Bob Berger
Hi Bob,
I found this interesting information;
https://extension.psu.edu/apple-skin-disorders-scarf-skin-and-russet
I had not heard of apple scarf. Yours is a perplexing case. It sure seems like just the skin cells are affected since you detect no internal damage.
Here is a link with lots of great photos to look through;
I'm going to send your problem on to an Extension person who can probably figure this out.
Sally
Sally,
Thank you! The links are great but you're right, I don't see my defect anywhere. I can take more photos if needed, I have plenty of examples.
Really appreciate your efforts here...
Bob
This phenomena is known as cracking. It is weather related—heavy rains and high humidity after a period of drought. It is probable that the humidity level is higher near the ground. It is also more likely to happen with russeting. Haralson apples are prone to russeting. Solutions include pruning trees to increase air circulation, use of plant hormones and avoiding certain chemicals. Read more about it at the following websites:
1. https://apples.extension.org/apple-fruit-cracking/
2. http://applescout.ca.uky.edu/fruitcrackingstemendsplittingandinternalringcracking
3. https://extension.umd.edu/resource/managing-apple-growing-conditions-prevent-fruit-cracking
4. https://www.ag.ndsu.edu:8000/agriculture/extension/extension-topics/gardening-and-horticulture/trees-and-shrubs/apple-trees/diagnosing-2
1. https://apples.extension.org/apple-fruit-cracking/
2. http://applescout.ca.uky.edu/fruitcrackingstemendsplittingandinternalringcracking
3. https://extension.umd.edu/resource/managing-apple-growing-conditions-prevent-fruit-cracking
4. https://www.ag.ndsu.edu:8000/agriculture/extension/extension-topics/gardening-and-horticulture/trees-and-shrubs/apple-trees/diagnosing-2
Hi Mary, thanks for the help. Cracking may be the problem but it doesn't seem likely for two reasons:
1). We've had no rain to speak of until the last week and I've seen it on the apples for at least the last 3 weeks.
2). The defect looks quite different from what's shown in the photos and it's very consistent north to south on the apple.
Anyway, thanks for trying!! This seems to be a tough one.
Bob Berger
Pictures can be deceiving. You may want to take it to a local orchard and get their opinion from several apples. Or you can send a sample to the Plant Disease Clinic for microscopic analysis.
https://pdc.umn.edu/
https://pdc.umn.edu/
Thanks again for your help Mary. Yes, they can be very deceiving. I will certainly let you know if I am ever able to find out what it is. I've been growing apples on these trees for 31 years and this defect is unique in my experience.
