Yellow spots turned to brown rust

[goodforyou]

My problem befor ten days ago is continuing.
Ten days ago i posted a problem with yellow spots (see link) https://www.icmag.com/ic/showthread.php?t=367721

but now some leaves have turned to rust.



Now they are in 6 weeks in flowering.



I looked under the scope the leaves, but I did not find any bugs, spider, crawles, eggs… They are clean. The rust is on the top of the leaves.


They are getting Plagron alga bloom + plagron green sensation in the rainwater one feed a week, pH is 6,5








.
I'm very worried it looks like a big problem. Can anyone recognize my problem?


Sorry to my bad English

 

[pongster]

hey bro,
my two novice cents:
- "damage" is only on the fan leaves attached to the main stem, starting from bottom to up. (i assume the lower leaves already fell or removed due to this "damage")
- there is no damage in the leaves of the buds, which are newer.

i've seen this before... in my own tent. pH lockout + typical and normal fade of flowering.

only a couple of weeks to harvest, those leaves are gone... i wouldn't do anything, doing amendment at this stage might impact on the flavour/smoke and will not do much for the fade and yield at this stage... let it finish.
best regards brother

 

[TanzanianMagic]

My problem befor ten days ago is continuing.
Ten days ago i posted a problem with yellow spots (see link) https://www.icmag.com/ic/showthread.php?t=367721

but now some leaves have turned to rust.

Now they are in 6 weeks in flowering.

I looked under the scope the leaves, but I did not find any bugs, spider, crawles, eggs… They are clean. The rust is on the top of the leaves.

They are getting Plagron alga bloom + plagron green sensation in the rainwater one feed a week, pH is 6,5

View attachment 510779

View attachment 510780

View attachment 510781

View attachment 510782 .
I'm very worried it looks like a big problem. Can anyone recognize my problem?


Sorry to my bad English

It's either potassium (K) or phosphorus (P) deficiency or lockout, and I'm going with K, because of the pattern of damage to the leaves. It could be P, because the damaged leaves curl upward. The damage moves up the plant, so it is most definitely a mobile nutrient deficiency (NPK, Mg).

The cause - that depends. Both are locked out at a low pH, and also with low root temperatures. Also, too much PK can lower the pH.

Nutrients - I don't know what the medium is that they're growing in: soil, coco coir, etc.

Either way, the problem may be the Algae Bloom.

Also, it is really important to know what the medium is that you're using to grow, because there are different nutrient formulas for different media.

These pictures are better than the previous ones, however it doesn't show where the plants usually grow - unless they're growing on that porch.

More info leads to better analysis.

They are getting Plagron alga bloom + plagron green sensation in the rainwater one feed a week, pH is 6,5

That'doesn't tell me - what nutrient concentration are they getting? What soil are you using? Are the plants on the floor or are they off the floor (root temperature).

My advise is to first fix the problem, and then get rid of damaged leaves, because at this point you can still get a good harvest. Cannabis plants don't need a lot of leaves to grow flowers.

 

[goodforyou]

hey bro,
my two novice cents:
- "damage" is only on the fan leaves attached to the main stem, starting from bottom to up. (i assume the lower leaves already fell or removed due to this "damage")
- there is no damage in the leaves of the buds, which are newer.

i've seen this before... in my own tent. pH lockout + typical and normal fade of flowering.

only a couple of weeks to harvest, those leaves are gone... i wouldn't do anything, doing amendment at this stage might impact on the flavour/smoke and will not do much for the fade and yield at this stage... let it finish.
best regards brother

Thanks brother. I removed the damaged leaves, now I will watch what happens.

 

[goodforyou]

It's either potassium (K) or phosphorus (P) deficiency or lockout, and I'm going with K, because of the pattern of damage to the leaves. It could be P, because the damaged leaves curl upward. The damage moves up the plant, so it is most definitely a mobile nutrient deficiency (NPK, Mg).

The cause - that depends. Both are locked out at a low pH, and also with low root temperatures. Also, too much PK can lower the pH.

Nutrients - I don't know what the medium is that they're growing in: soil, coco coir, etc.

Either way, the problem may be the Algae Bloom.

Also, it is really important to know what the medium is that you're using to grow, because there are different nutrient formulas for different media.

These pictures are better than the previous ones, however it doesn't show where the plants usually grow - unless they're growing on that porch.

More info leads to better analysis.

That'doesn't tell me - what nutrient concentration are they getting? What soil are you using? Are the plants on the floor or are they off the floor (root temperature).

My advise is to first fix the problem, and then get rid of damaged leaves, because at this point you can still get a good harvest. Cannabis plants don't need a lot of leaves to grow flowers.

I put one plant on the porch to take a better photo in daylight.


In this condition are two Northern Light plants. The rest looks are OK.


I grow in a tent. Temperature by day is 24 ˚C, by night is 19 ˚C. Moisture is 50-53%.

All plants are treated equally and the same time. I use Plagron grow mix soil in 8L fabric pots.


What do you suggest that I flush the plants?
THNX for your help and time.

 

[Teddybrae]

It's fukn SENESCENCE! Your plant does not need these leaves any more because it is now into flower and all the nutrients in those (OLD) leaves has moved to the flowers. This is NORMAL especially for Sativa varieties. (It's like when human hair turns grey. Pretty soon the human will be finished.)

 

[TanzanianMagic]

I put one plant on the porch to take a better photo in daylight.


In this condition are two Northern Light plants. The rest looks are OK.


I grow in a tent. Temperature by day is 24 ˚C, by night is 19 ˚C. Moisture is 50-53%.

All plants are treated equally and the same time. I use Plagron grow mix soil in 8L fabric pots.


What do you suggest that I flush the plants?
THNX for your help and time.

Also:

- What is the nutrient concentration?

You should also check the EC/PPM of the run-off of the first drops of clear water you can pour through the medium.

It is likely that the plant isn't absorbing all the nutrients, and they're building up in the medium.

- The stake

It looks like a source for infections. It looks like potassium deficiency/lockout, however there could also be some leaf septoria or mildew involved.

 

[goodforyou]

Also:

- What is the nutrient concentration?

You should also check the EC/PPM of the run-off of the first drops of clear water you can pour through the medium.

It is likely that the plant isn't absorbing all the nutrients, and they're building up in the medium.

- The stake

It looks like a source for infections. It looks like potassium deficiency/lockout, however there could also be some leaf septoria or mildew involved.

Thanks again for your thoughts.

Is it necessary to measure EC / PPM in organic fertilizers?



Plagron writes, if we use organic fertilizers we don΄t need to measure EC / PPM. Also, in organic schedule (Canna, Biobizz, Plagron…) is not indicates EC / PPM value.



Anyway, I'm going to use an EC meter, but I'm not sure if schedule for soil will bi OK to check EC / PPM.



Kind regard

 

[TanzanianMagic]

Thanks again for your thoughts.

Is it necessary to measure EC / PPM in organic fertilizers?

Plagron writes, if we use organic fertilizers we don΄t need to measure EC / PPM. Also, in organic schedule (Canna, Biobizz, Plagron…) is not indicates EC / PPM value.

Anyway, I'm going to use an EC meter, but I'm not sure if schedule for soil will bi OK to check EC / PPM.

Kind regard

An EC/PPM meter is the only way to accurately know how much nutrients you are feeding the plant. Including bottled organic nutrients.

You should flush the plant slowly with clean water, and then feed 0.4 EC of the high P/K Green Sensation, plus 0.1 EC of epsom salt.

Also, there is no real need for the algae bloom yet. Personally I've never liked the stuff. If you use it, you should used in very small amounts (start with 0.1 EC), because it is basically a fertilizer on it's own.

 

[goodforyou]

An EC/PPM meter is the only way to accurately know how much nutrients you are feeding the plant. Including bottled organic nutrients.

You should flush the plant slowly with clean water, and then feed 0.4 EC of the high P/K Green Sensation, plus 0.1 EC of epsom salt.

Also, there is no real need for the algae bloom yet. Personally I've never liked the stuff. If you use it, you should used in very small amounts (start with 0.1 EC), because it is basically a fertilizer on it's own.

Thanks again for your help and advice. You helped me a lot. Now i'm going to buy EC meters.

 

[Cvh]

I really don't see the point of measuring EC in Organic.

EC measures Electrical Conductivity of salts dissolved into a liquid. Organic nutrients haven't yet broken down into salts. They are still organically bound.

Here is a short article about EC/PPM and why it's not much of a help if you grow organically.
https://www.google.com/amp/s/blueskyorganics.com/growing-guides/ppm-and-you-a-quick-guide/amp/

Try to get yourself also a copy of a good book about growing organic (Cannabis).

Here are some book recommendations:

Teaming with Microbes by Jeff Lowenfels
True Living Organics by The Rev

Peace

 

[TanzanianMagic]

EC measures Electrical Conductivity of salts dissolved into a liquid. Organic nutrients haven't yet broken down into salts. They are still organically bound.

If they're dissolved in a solution they're measurable. And Algae Bloom is almost like a molassis based nutrient solution in itself. And of cours Green Sensation is synthetic - and it's great, I use it myself on some plants, rarely, when I want to stimulate fast root growth because of the phosphorus.

If you measure runoff you'll know. And Algae Bloom most definitely can burn the roots of plants.

 

[Cvh]

^Adding organic matter to water doesn't break the organic bound. If you measure an EC, the result will be off. Organic matter added to water doesn't instantly turn into electrical conductive salts...

 

[TychoMonolyth]

Every time I get that my soil is way too hot. I flush in the tub for 5 minutes. I'd cut the soil 50/50 with something like coco or cheap potting soil and perlite. Transplant may be in order.

 

[Cvh]

https://www.google.com/amp/s/blueskyorganics.com/growing-guides/ppm-and-you-a-quick-guide/amp/

...
I’m growing organically and my readings are way off!

Yeah, this gets a little complicated. PPM are a straightforward measure for hydroponic or standard, synthetics-based growing. There’s a set number that’s ideal for each stage of growth, and that’s it. Organic growing is a little different. Part of the philosophy of organic growing is that the nutrients don’t just come from some refined, synthetic fertilizer. The soil itself should be fortified and made nutritious for your plants using natural, organic ingredients. Why does this affect PPM readings?

Rich, healthy organic soil is more complex than artificially fertilized soil or hydroponic solutions. The nutrients are stored in more complex molecules than with artificial fertilizers, that are released slowly over time. EC meters work by measuring the electrical conductivity of salts in water; organic nutrients haven’t yet broken down into simple salts. It’s like the difference between complex carbohydrates found in whole grains and refined white sugar. The organic nutrients get broken down by microorganisms over time, much like complex carbs get broken down by our digestive system. Therefore, the PPM readings you get from organic soil won’t reflect the actual nutrients that soil contains.

However, they may not be lower, as you might expect them to be. Why? There are plenty of non-nutrient solubles found in organic fertilizers that can confuse your readings. Remember how we talked about solubles in tap water earlier? This is a similar concept; many organic soil additives can end up adding acids and carbohydrates that are electrically conductive, thus throwing off your TDS meter’s EC readings.

Is it worth testing organic soil for PPM?

Good question. Due to the complex nature of organic soil, EC readings will be too inaccurate to determine whether the appropriate amount of nutrients are present in the soil. To determine if organic soil is well-balanced for your growing system, you’ll need to carefully monitor pH, watch the plant for signs of nutrient deficiency or imbalance, and learn from experience. If you have the resources, you can send a soil or plant matter sample to a lab for analysis. Alternatively, you could always rely on our simple four-step process for growing flavorful and potent organic cannabis.

 

[TanzanianMagic]

^Adding organic matter to water doesn't break the organic bound. If you measure an EC, the result will be off. Organic matter added to water doesn't instantly turn into electrical conductive salts...

Have you ever poured Algae Bloom into a quart of water and observed whether it increased the EC reading? Because it does. And the reading is and remains stable, which is how you know.

 

[goodforyou]

Thanks guys for yours discussing and sharing the experience.

Very good article about EC/PPM.

I'm going to do some EC tests on my flushing plant and solutions.

 

[NEED 4 SEED]

It's fukn SENESCENCE! Your plant does not need these leaves any more because it is now into flower and all the nutrients in those (OLD) leaves has moved to the flowers. This is NORMAL especially for Sativa varieties. (It's like when human hair turns grey. Pretty soon the human will be finished.)

Not necessarily. I sometimes have the same damage also in veg.