indoors.. outdoors..??

in the ground?? .. potted??

i think we need those pix also ...

and once you get those pix up ... there is a very active fruit forum for other opinions ...

if you dont know.. what you have there.. is understock.. for grafting.. should you ever wish to try that ... otherwise .. there is no way to know the 'quality' of your seed grown apple.. short of growing them for a very long time.. to get an apple off them ...

regardless .. it most likely is NOT a pest.. but one of the many diseases that afflict apple/malus ...

and what you will find.. is that apple.. in terms of 'production' involves a very proactive use of chemicals.. up to 6 times per year .... i am sure there are ways to do it organically.. but these wont be a plant and forget.. and hope for harvest type of thing... nor a pop into the GW and wing it thing.. you will need to start researching all this and become VERY proactive .... and the fruit peeps can help you with IPM ... integrated pest management.. which would also include disease ...

ken

Here is a link that might be useful: apple leaf diseases ....

drew, we need more information from you to be able to offer any truly helpful advice. Pictures are very important.