I have a semi-dwarf Golden Russet apple tree planted in my back yard. I planted it last year (along with an Ashmead's Kernel) as bareroot stock, about 3-4' tall and slightly branched. I sprayed it with a basic horticultural oil in late winter while it was in the silver tip (very close to green tip) stage. It leafed out very well this spring. Today, I noticed some markings on my leaves. Is this anything I should be concerned about- is it early scab, fire blight, cedar rust, something else, or does it just need more (or less) water? I have not noticed any aphids or other bugs near these trees. I have included both a closeup of the leaves, and a full photo of the young tree.