Yellowing leaves a sign of heat stress?

[gasificada]

Has anyone ever experienced yellowing leaves as a symptom of heat stress?

I have two lots of plants; one lot at my place and one lot at my mum's place. I treat both lots almost identically (same soil, same fertilizer, I keep the soil at the same moisture level, etc, except for the plants at my mum's receive far more sun). Now here's the thing: the ones at my place are very green and bushy while the ones at my mum's are starting to go yellow (particularily the old growth) and I am thinking heat stress or something similar may be the cause.

Unfortunately I do not have my camera with me at the moment but I will try and get photos up either tomorrow or the day after. For now I will try and give a bit more detail though....
- it is particularily the older growth that is yellowing
- some of the yellow leaves are blotched with a light green (not quite yellow, not quite green)
- burns on some of the edges of the yellow leaves
- veins don't appear to be darker or lighter than the rest of the leaf (hopefully rule out some deficiencies or overdoses?)
- new growth is light green instead of a healthy green and sometimes curling upwards (I have had the same curling appear on younins that have sat too close to a hot light)
- main stems appear to be OK (i.e. normal colour)
- plants are still setting pods

Could these be symptoms of heat stress? Or if it is not heat stress per se, could heat still be a factor? (e.g. affect by increasing or decreasing the uptake of nutrients, etc?)

 

[Timmmy newbie]

bbooo I just replied and it vanished

Eck and again.

A few of my plants are displaying the same symptoms. The wierd bit is that its only a few and not all of my plants. I treat all the plants the same way but only two of them look bad. I've been dosing mag and cal and nothing seems to be changing.

The weathers wet and fairly cool here at the moment so maybe thats all it is but it doesn't explain why only two of my plants are like this.

I'm trying to lower the ph of the soil to see if that helps.

Will keep an eye on this post, hope you find the answers.

 

[gasificada]

Thanks Timmmy, I hope we both find our answers!

I managed to take a couple snaps today....

I know they're not the best but it was pissing down rain so I had to be quick before me and my camera ended up soaked to the bone (something I could probably live with but my camera sure as hell couldn't!).

 

[gasificada]

And just for comparison, the plants at my place....

(They were germinated and potted up at the same time as the others.)

 

[megamoo]

Some of my plants are displaying the same things with the yellowing and dying off of the lower down older leaves. It has been very hot here in Perth, I am going to set up a shadecloth screen for them so they don't bake through summer. I am also a high risk person for over watering and fertilizing too.

What are any other differences you can think of between the conditions? Are there neighbours at your mum's place who spray pesticides or something like that? Night temps? High winds?

After a second look at the pics I do immediately think too much hot sun.

 

[franzb69]

yellowing could be due to overwatering.

 

[Timmmy newbie]

I would consider the first two pic's as being normal for lower old leaves. At some point their going to die off and drop.

The visual difference I see is that your pots look like they must be fairly well sheltered from the rain and weather. The pots with the yellow plants look like there out in a yard getting lots of rain and colder night temps but I would be guessing yours are getting a lot of heat from their surroundings during the night along with shelter from the rain..... maybe lol

Don't mind me I had a blinder of a night lol

 

[gasificada]

I would consider the first two pic's as being normal for lower old leaves. At some point their going to die off and drop.

The visual difference I see is that your pots look like they must be fairly well sheltered from the rain and weather. The pots with the yellow plants look like there out in a yard getting lots of rain and colder night temps but I would be guessing yours are getting a lot of heat from their surroundings during the night along with shelter from the rain..... maybe lol

Don't mind me I had a blinder of a night lol

Definitely.... sounds logical to me!

I'm going to move the ones at my mum's under the shade for a couple weeks and see if it makes a difference. Whatever is causing it is sure to do with the fact that they are doing it a bit more rougher than the ones at my place.

 

[jolokia_jas]

Another possibility is that they could be root bound, they are getting more sun than those at you're house so could be growing faster, I'd just pop one out and check and if it is problem solved. I had the same yellowing when my plants got root bound a fair while ago. It's an easy check and quick result. If they are root bound just give the roots a bit of a tease before you pot them up. They don't look to be too big for those pots though so that probably won't be the case, can't hurt to check though.



And Timmy I remember you saying in you're thread that you didn't cut the root ball back on a couple of you're overwintered plants, are htese the ones that are yellowing?

On the other hand a couple of those leaves do appear to have slight sun burn but that would be more apparent on the upper leaves as the lower ones would be shaded by the others.

Also if you've been having rain like I have then quite possibly they are getting too much water and flushing all the nutrients out of the pots before the plants can get any. Are you using liquid ferts or granulated? if you're using liquid try granulated so they don't get flushed out as quick and the plants get a chance to use them.

Just my 2 cents. Hop it helps.
And good luck



Jas