My "stump" Oak disease or sunburn or Jap. beatle

I collected this "stump" Oak three years ago with few 4" new shoots and transplant to my garden. Was just curious how is gonna root and if it will survive. "Stump" is doing good I did some basic pruning and give some bonemeal fertilizer. The weather this summer is hot and humid. After tree start second shoots this happend...drying back? sun stroke? fungus? jap.beetle? or all this together? I sprayed with Bordo on Sunday evening [first treatement] Also did some insecticide two weeks ago Malathion [aphids, jap.beetle] Can someone respond on this? Any experience as such would be high appreceated

Yesterday I went to closed by nursery and they have most Jap. Maples sheded under pergola and they all look like my Oak. So probably not sun burn? Is strange nobody has comented on that yet?

Hard to say for sure, my guess would be japanese beetles. But, the black could be bacterial / fungal or sunburn. So my comments really don't limit the possibilities.

I would consider treating for the beetles, a product like Bayer Tree and Shrub, but check the label to see if it lists Japanese beetles.

For the possibility of fungus / bacterial problem, at the growing end of branches I think it could be combated by placing the trees in more exposed situation, more sun and air movement. Oaks usually want a fair amount of sun. They are not an understory tree. Another possibility it water. In some cases too dry between waterings will blacken newer growth, this damage is largely mechanical, being caused by the lack of water. What is surprising is that damage to the roots from too much water can cause new growth to blacken, though the cause is more often fungal or bacterial, but the dying roots don't move water around well and the new growth, looks like it has been burnt by too much sun or drying out. SO check the soil, dig your finger in and check before you water. If 1 inch under the surface it is very wet, you might have been watering too much.

So I really haven't narrowed down the source of your problem, but if you check the soil you might be able to eliminate the 2 possibilities of too much or too little water. Only you know how much sun the tree is getting, it could also be caused by heat stress.

Does the sun beat on the side of the pot? If in the middle of the day, you touch the outside of the pot, and it is hot to the touch, the sun might be cooking your roots. In which case use plywood, or styrofoam or cardboard to make a temporary shade to keep the sun off the pot.

All these are possibilities. Check them out, a good chance one of them is causing your problem.

Thanks Leo for very knowledgable respond. My bad I didnt mention the tree is planted in open ground. When I found it there was almost no fine roots and "stump" was already digged out and left bareroot I don't know how many days. Chance for survive was like 1: 1000!! Than I decided to plant in garden. Amazingly tree/stump start budding next spring and I have it for third year. I think I'll grow it another one or two years with hard pruning and will see if is ready to transplant to a pot. So with this more details about tree origin will help to give correct advise. So far sprouts are very vigorous and I do hard prun them and they keep growing. After two treatment with Bordo rust on leaves stoped and jap. beetles sezone is over too I guess.

Powdery mildew, that's what that is. If you go into the woods right now you'll probably see all the young saplings in the understorey covered in it. It's very common and rampant on oaks that have DRY roots and poor air circulation. Easy enough to kill, though, with most garden fungicides.

Japanese beetles are the work of Satan.

Check for thrips. Contact your local extension agent. The Bayer Tree & Shrub may do the trick. Prune off the affected shoots & sterilize your clipper.
Iris

Thank you Treedwarfer and Iris. Thats basicaly what I did [aplyed fungicide] just have to clip the new shoots.