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Question from Angela (received 6/19/20) -

I have some brown spots coming up on the leaves of two recently planted apple trees (a honey crisp and a braeburn). Do you know what the problem would be? Thank you for your help!

Answer from Marion Murray, Utah Extension Integrated Pest Management (sent 6/19/20) - 

That is a fungal disease called apple scab. Although it is around, we rarely see it causing any damage on Utah apple trees because of the hot, dry weather.  But when conditions are like what we have had in June (cold and rainy), then it can show up.

The weather is expected to get hot and dry again, so the fungus will not continue to spread.  Therefore, a fungicide application is not warranted.  The leaves showing infection now will remain as they are, but there shouldn’t be any more spread.

However, if you use irrigation that lands on the foliage, then yes, this will cause further spread and a fungicide is warranted.

The disease may show up next spring, so you can use Spectracide Immunox right after bloom, and repeat 2 weeks later.

Feel free follow up with me if any more questions arise.

Take care