Chlorosis on an apple tree.

Asked July 7, 2020, 4:40 PM EDT

Is it safe to keep spraying my tree every 2-3 weeks to correct the chlorosis with the apples on it? Will this affect the edibility of the apples?

Pennington County Minnesota

3 Responses

It would be helpful to know what you are spraying with. Apple trees aren't typically chlorotic. Have you had a soil test done to determine the pH of the soil (which can lead to chlorosis)?

As for safety issues, read the label. The label is the law.

I have sprayed my apple tree with chelated iron once several weeks ago. I thought I would spray it once more since it still looks slightly chlorotic. I have slightly alkaline soil and have added sulphur this spring and in the past. The tree hasn't shown these signs before, but we had a very wet fall and a wet spring which seemed to promote the chlorosis ( 8-9 inches this spring ). I wasn't sure if I should spray again since the apples are developing. It doesn't list any specific fruit bearing trees on the label. It has no mention of anything about spraying while there is fruit. I know the spray is a short term fix until I get the pH right.

Thanks for clarifying things. Typically apple trees don't need to be treated for chlorosis. While chlorosis can be somewhat weakening, it doesn't usually require treatment. Slightly alkaline soil (pH below 8, for instance) won't usually cause it in apple trees (I grew apple trees that were not chlorotic in 7.8 soil). If you've not done so already, get a soil test done:

Excess water can have an effect on iron uptake by trees. The drainage of your soil may be the issue here, and soil amendments, like foliar sprays, will only be short term fixes.

As for the specific question about chelated iron affecting the apples, I've not read anywhere that it does, and numerous places recommend it on fruit trees for treating chlorosis. For instance:

I've seen labels that place no restrictions for use on vegetables. So I see no reason why you couldn't use the product when there is fruit on the tree.