Neem disease

I have a neem sapling that is in a pot. It has been growing nicely and very soon I will need to give it away to be planted in the ground. Lately I am finding that the bottom leaves of it are turning yellow at the edges. The leaves have started to be covered with what looks like brownish dust. Also there is little resin exudate oozing out. Can someone help me identify what needs to be done. Is it nutritional deficiency or is it some form of infection. Please guide me with necessary actions to be followed. I am a newbie to gardening.

 

Any ideas as to what is wrong? This started all of a sudden. This started from the older set of leaves and now almost the whole sapling is covered with brown dust. The bottom leaves are yellow at the edges. Resin exudate now I can see near the new leaves too.