Either water starved or fert burn. Its a SHB of some kind but really know way to tell what vareity untill you get some fruit. Even then its just a eduacated guess. The leaves shape resemble Emerald but there are many varieties with leafs like that. I dont see any mulch in that pot. A 3 to 4 inch layer of course pine bark mulch will do wonders for blueberry in a pot. You should be watering daily at this point in the summer and the mulch will keep it moist and some what cooler in this heat.

After thinking about it, it could also be some kind of bacterial canker of some kind but more than likely water or fert issues.

To me it looks like they dried out...small pots and heat sometimes twice a day watering may be needed.

Ok great! Will add some mulch today. I have red mulch, will that work? I think it is pine. I do water it daily, and actually added some fertilizer after it started looking brown. Thanks for the help!

Do I need more than one blueberry plant to pollinate and get berries? I got one blueberry this summer and then a bird ate it! Lol

I have seen this on my blueberries and it is due to a couple of possible reasons: one, the roots of the plants are drying quickly therefore mulch is needed, if not already provided. This will help retain uniform moisture that most berries (except grapes) will need to survive.

Another factor is acidity, that causes blueberry roots to be unable to absorb nutrients. Under this situation, no matter how much more fertilizer is added, it will be useless or only marginally useful.

Very similar problems may be found due to iron deficiency in the soil, or due to insufficient acidity.

To cure the second problem, I have found that soil acidifier AND iron chelate added to the area proved to cure the issue.

My recommendation would be to try all 3. Blueberries die really quickly and you do not want to wait and watch.

Hope this helps, and please post back what worked and what did not.