That is a pretty strong AS mix. So fertilizer burn would be my first guess. When you say watered in well what does that mean? Apply the mix and then plain water immediately?

Funny with the recent talk about AS in this forum. I thought that 1 tablespoon per 2 gallons (I think you actually said 2 1/2 gallons) was about the amount that you stated that you used to use, in your 1 and 7 year blueberry thread, and you were using it on much smaller plants :-) Anyway, every 2 weeks on this 3 year old bush I usually water first and then apply so it gets drawn down in. Should I water heavily/flush the container and see what happens? Maybe this Kabluey is more sensitive to the AS than the others. Thanks. Ed.

Could also be some kinda of bacteria/canker. Your plants look very healthy Ed! Keep up the good work. It shows, very nice plants;)

I there anything I can do if it's some kind of bacteria/canker? I'm going to flush the pot this morning, and remove any more affected leaves. I'll probably remove the affected branches. Sorry for the pictures at dusk yesterday. Wanted to get them posted asap. Ironically the Kabluey was growing the best of all of them, extremely dense foliage and practically out of control. I had to prune a few lower branches just to be able to water it. Very good sweet berries too. Well, this ought to take it back a notch :-)

Ed,

Don't remove the branches. Dry ground then fertilizing is not a good idea. Even if you water first then hit it with the fertilizer is not good. Water today fertilize tomorrow much better or if the pots dry out that fast water wait a couple 3 hours then fertilize. It lets the plants soak up the water first to fill any moisture deficit they may have so they then take the fertilizer up slowly. All that being said I don't think it is fertilizer burn anyway. Fert burn is almost always a leaf edge in burn at least on some to most of the leaves.

I believe what you see is gloeosporium? Or a fungus of some sort. Has it been very rainy up your way? How is the fruit does it show any effects?

OK thanks everybody for your responses. It has been very rainy. 13" since June 1. If you notice there is also red spots on some of the leaves. The rain might have something to do with it, even though the container drains well and they are in a breezy spot to dry out quickly, the foilage is very dense which might be part of the problem. The little bit of fruit that it bore this year didn't seem to be affected at all....big sweet berries....the best of the lot actually. I flushed the soil this am and didn't remove any leaves or branches. I might remove some leaves later. I was going to spray with a fungicide, but on my Daconil bottle there was no instructions for blueberries, so I figured Daconil wasn't intended for blueberries. Is there anything else I can do, or is it a waiting game? Why not remove a few branches? Wouldn't a little pruning possibly benefit as well as get rid of affected branches? Thanks again. Ed.

Ed,

I misunderstood what you meant.....I thought you were going to take off any branches that showed a sign of the problem. Removing a few branches to let in more air is a good idea. There is nothing wrong with removing the diseased leaves.

Ed:

The rate I recently posted about was 1 teaspoon (3 teaspoons=1 tablespoon) per 2.5 gallons. Your concentration is nearly 4 times stronger. Yours is near or above the rate that caused damage in the referenced study. Your rate is only safe if it's followed and/or preceded by plain water. One teaspoon, 5 ml, per two gallons would be fine.

Here is a link that might be useful: mixing rate for 21-0-0

Looks environmental, as in recent heat wave with direct sunlight.

Also, the containers appear to be small for such large plants. Easy to run out of water before you realize it!

Bamboo: You understood correct, I was thinking of removing the affected branches, which weren't that many anyway, but I won't do it. Will probably just remove the bad leaves and prune appropriately.

Fruitnut: I saw the recent discussion about the lower application rates for AS, but I was having good results (until possibly now,) with the old rates. Will definitely have to rethink how much AS I'm going to give them. I do apply it preceded with plain water.

Update: Another bush, our Farthing is also showing signs of the same thing, so I flushed that container also. Something else that might be at play is the weather in that it was warm and rainy and now is sunny, and hot 90+. Maybe some sun damage?? Today when I was researching blueberry diseases I saw the red ringspot virus. The pictures are exactly what I have on some of my bushes and I think almost everybody gets the stuff from time to time and I've seen lots of posts from people asking what the red spots are. No cure for the redspot virus except removal of the leaves.

I do agree with bamboo and jean, your issue looks more like heat/too dry rather than fertilizer burn. So it's probably the sudden change in weather and not enough watering. But I've burned them with AS and it's easy to do.

Fertilizer burn would damage the entire plant.

this damage is one-sided.

Jean, sorry I missed your earlier post. (Edited: We were both just typing at the same time) I agree that it might be environmental, but the pots are not that small. The bushes have practically doubled in size in the last 2 months w/12"-18" of new growth. Besides the nursery pot with the 2 y o Sweetcrisp, the smallest container is the 5 gallon bucket in the foreground. The small beige pot is not a blueberry. None of the plants are more than 3 years old, and the largest one, the one I had the problem with, is in the largest container, about 15 gallons. There is a 25 gallon 5 year old Blueray barely visible in the back right, loaded with berries and covered with tulle for bird protection. All that being said, I think you might be right and I overestimated how much rain was actually getting in the pots, and then the hot sunny weather. FWIW I have four, 25 gallon pots standing by for some major potting up this fall :-)

This post was edited by edweather on Wed, Jul 17, 13 at 0:37

Ed,

It is probably a combination of factors and that is where it gets tough to diagnose. Stress on plants can be shown in many ways and it makes things happen that would not if the plant was happy.

I don't worry much about the fungus..some years it is bad here and some years not..this is a not year:) The plants don't seem to care much in either case but I do hate looking at those splotchy leaves.

I'm having problems with tomatoes in pots, well just one. My blueberries in raised beds are doing great in this weather. If your problem is too much water, and you flush the pots, it should get worse. Plants are tough to grow!

Bamboo, fruitnut, and jean, Looks like it was probably lack of water. The browning leaf issue that was accelerating quickly 2 days ago has basically stopped. Am watering every day now with the 90+ heat and sun. No problem with overwatering, the mix drains well. Yeah, I'm not too worried about the fungus, it was just fun to find out what it is. I have a little of it every year. Thanks to everybody.