Apple tree health

Question: I have a large mature apple tree that this year has a ton of apples.

All of the apples have a scab or rust on them.  Picture attached.

Any ideas how I can slow this for this year and prevent in future?

Also it's a very large mature tree and desperately needs to be pruned, any guidance for pruning a large mature tree?

responder: An Ask Extension Expert Replied July 22, 2023, 12:09 PM EDT
response: Hello,  Here are two (2) publications that will be of great benefit to you:  Check out: Chapter 2 - Tree Fruits - See Pages 30 through 32 - Pruning Mature Fruit Trees and Pruning Old, Neglected Apple and Pear Trees Chapter 7 - Pest Management and Disease Control in Home Fruit Plantings (Apple and Pear Diseases - Page(s) 87 - 102)) in the Midwest Home Fruit Production Guide - Cultural Practices and Pest Management Bulletin 940 from the Ohio State University Extension is at this link:  https://plantpathology.ca.uky.edu/files/mw_home_fruit_productn_b591.pdf   I highly recommend that you purchase the bulletin because you will get the latest information! The Bulletin is 148 pages in length and handles tree fruit and small fruit - If you want to purchase this Bulletin ($26.00), go to this link:  https://extensionpubs.osu.edu/midwest-home-fruit-production-guide/   Check out:  Controlling Diseases and Insects in Home Fruit Plantings - Bulletin 780 Spray Schedules for Pest Control on Apple and Pear - The Ohio State University Extension is at this link: https://cuyahoga.osu.edu/sites/cuyahoga/files/imce/Program_Pages/ANR/DigIn/Controlling%20Diseases%20and%20Insects%20in%20Home%20Fruit%20Plantings%2C%20Bulletin%20780%20%28whole%29.pdf.   I highly recommend that you purchase the bulletin because you will get the latest information! The Bulletin is 42 pages in length and handles tree fruit and small fruit - If you want to purchase this Bulletin ($5.00), go to this link: https://extensionpubs.osu.edu/controlling-diseases-and-insects-in-home-fruit-plantings/  Management - Apple Scab Apple scab overwinters in leaf litter as small black fruiting structures called pseudothecia. Ascospores, the primary inocula, form in the spring and are discharged in response to wetting events. Ascospores can be released as early as green tip, but peak ascospore release generally coincides with bloom. Apple scab is managed primarily through the application of fungicides from green tip through midsummer. The destruction of leaf litter in the fall by flail mowing or through the application of chemicals that hasten leaf litter degradation, such as urea, helps reduce primary inoculum. The severity of infection depends on varieties inherent resistance. Cortland, McIntosh, Paula Red, and Crispin are extremely susceptible; Delicious, Empire, Gala, Golden Delicious, Ida Red, and Spartan are moderately susceptible. Resistant varieties include Goldrush, Enterprise, Florina, Liberty, Jonafree, Macfree, Novamac, Nova Easygro, Prima, Priscilla, Sundance, Scarlet OHara, and William's Pride. From the MSUE article: Apple Scab - Integrated Pest Management - Michigan State University at this link: https://www.canr.msu.edu/ipm/diseases/apple_scab  Management - Cedar Apple Rust Eliminating red cedar trees in the vicinity of orchards helps to reduce disease pressure. However, it is difficult to remove all sources of disease because the infective spores can travel on air currents for several miles. Pruning the "cedar apples" from cedar trees is an alternative to removing the tree itself. Where the disease is a problem, fungicides are applied from tight clusters through petal fall. The varieties Cortland, Crispin, Golden Delicious, and Jonagold are susceptible to both cedar apple and quince rust, Ida Red and Paula Red are susceptible to cedar apple rust, and Delicious and Empire are susceptible to quince rust. From the MSUE article: Cedar Apple Rust - Integrated Pest Management - Michigan State University at link: https://www.canr.msu.edu/ipm/diseases/cedar_apple_rust  I hope this helps!

responder: The Question Asker Replied July 22, 2023, 2:00 PM EDT
response: Thank you for the detailed response.My large apple tree I've nursed back to health since I got the property.Is there. a way to DNA test the tree to determine what type it is?-seanOn Sat, Jul 22, 2023, 12:09 PM Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied July 22, 2023, 4:48 PM EDT
response: Hello,  Your question: Is there a way to DNA test the tree to determine what type it is?  Here are two areas that may answer your question.  Gardening hotline at <personal data hidden>. Mondays, Wednesdays, or Fridays - 9:00 a.m. -12:00 p.m.  MSU Plant and Pest Diagnostic Lab Lab email: <personal data hidden> Lab phone:<personal data hidden> Hours of operation: Monday through Friday, from 8:00 AM to 5:00 PM.  I hope this helps!

responder: An Ask Extension Expert Replied July 22, 2023, 5:56 PM EDT
response: UPDATE!!  Here is another response from another responder back in 2020:  I assume that you are trying to identify what apple variety you have. Michigan State University does not do genetic testing to identify apple varieties. The University of California Foundation Plant Services https://fps.ucdavis.edu//dnamain.cfm and several private firms do testing. At the U of Cal facility, the cost is about $355 for one sample. This testing works only if they have your particular variety in their database. The last time I looked at the number of varieties in their database was not very extensive.   William Shane Replied on May 28, 2020, at 8:24 AM EDT  I hope this helps!