Posted: 27/10/2013 at 09:35
Good morning! Unfortunately the quality of your pictures is not good enough to show the detail needed.
The browning of the stem is probably due to aging and thickening to support the plant.
The white 'leaf' you refer to I can't see well enough to comment on.
As has already been mentioned, the prospect of getting apples - if this is indeed an apple seedling, is a long way off. Apple trees are usually grafted not grown from seed. Certainly continue with growing your seedling, I would like to see some future pictures but in order to produce apples within your life time, you will have a much better chance in purchasing a good young tree from GC or a supermarket in spring.