I'm not positive what that might be...but keep a close eye on it incase its a fungus of some kind and spreads? Since you've only had it since July...Lowe's has a one year guarantee on their trees as long as you have the receipt. You can always exchange it if you think that "stuff" might spread or you can spray it with "fungicide"...try and get a clear picture and take it to local fruit nursery and see what they think it could be. Good Luck!