I have a young cucumber seedling/plant. It's ready to go to its position in the garden now, but I'm really concerned about the damaged leaf. Is this infectious? What should I do to make sure the other leaves remain healthy?
Here are the photos:
Just to confirm, I can't see any insects or anything else, the plant has been grown indoors from seed. Other plants from the same seed packet seem to be doing just fine, the plant pictured is the only one that seems to be affected.
(very amateur gardener, obviously )