Rusty Spot on my Blueberry only like two weeks left?! What now??

[PrezDickie]

Photo period blueberry grow in soil under led she just started to get so lightening and yellowing edges of lower leaves but these random "rusty" spots are showing up toward the buds near the top? and i don't know what they are? i'm already a few days into final flush is this mite damage? a mold? what? and do i need to worry? i've been cutting it out where every it shows up

 

[PrezDickie]

yikes whole night up on the forum and no responses, maybe i do have a weird problem, just hope someone can ID this for me

whatever it is it just isn't on the leaf surface its causing small spots on the back of some and you can see the damaged area thru the back

 

[astronomy420a]

hey mate, at this point, i think everything is fine!! not alot of the rust, what your doing is right, anything with rust remove,
and i think flushing will take care of it! cut the brown out and leave the green part of the leaf, the buds will suck out whats left in the cut leaf as she winds down:smoke: your in like flint!

 

[lostboy]

Hi,
I have similar probs. always happens in late flowering.

I add cal/mag in the correct amount then some more thinking it a def
But it makes no difference.

Hope you get it sorted and if I do I'll let you know

Lostboy




This is one example. I have more which look more like yours. I try and post them later for comparison. Peace

 

[The Medicine Man]

Some plants late in flower get very very hungry for mag. blueberry wasn't something I thought would get very hungry for anything tho. I've got one running right now and it can't take nutes at all like the rest of my plants.

 

[Muddy]

If you're that close to harvest it's just the plants starting to feed off the stored energy in the fan leaves. Very normal and not something to worry about. By the time they are ready to harvest all those fan leaves will have turned yellow and died off. Don't remove them, just leave them and let nature take it's course.

 

[PrezDickie]

the fan leaves are just starting to turn lighter green and yellow at edges but these rusty spots are almost all on sugar leaves by buds?

 

[Hugo]

It looks like Mn deficiency.

At the newest leafs it must be an imobile micronutrient. From the litterature I gather it's most simillar to Manganese deficiency/toxicity.

First deficiency symptom usually is a interveinal chlorosis of young and then older leafs before necrotic spots appearing.
First toxicity symptom is a chlorotic, dark orange, rusty-brown mottling on the younger leafs. Progression to older leafs after. Growth is slower and overall vigour is affected. Toxicity is compounded by low humidity. Increased transpiracy augments manganese transport into foliage. Low pH can cause that toxic intake of Mn. It also causes deficiency intakes on iron and zinc.

Looking at your pics I'd say it's Mn Toxicity. Treatment is being investigated at the moment. Prevention goes throught maintaining a soil pH at 6.3 and above.

 

[Hugo]

http://aciar.gov.au/files/node/2200/mn061_part_6_pdf_51477.pdf

 

[low_and_slow]

How did this turn out in the end? I get something similar late in flower when my pH is below 6.0...was curious if you ever resolved it or if the plant just finished off and lost some sugar leaf.