Hello,

This looks like Gnomonia leaf blotch, a minor disease of strawberry. If you only see a few lesions and they remain restricted to the edges of the leaf, there will be no need to control it. if it seems to be spreading, make sure that leaves are not kept wet overnight e.g. from irrigation water (irrigate early morning so that leaves dry off during the day). Common fungicides recommended for other leaf spot diseases should work if needed. You are welcome to send me some leaves in the mail for confirmation of the fungus. Best wishes,