Rust

[THC123]

Hi guys

I think i have rust on my greenhouse girls.

Brown spots on leaves

Tomorrow i can take pics, anyhow i just wanted to know, how fast can this ruin the plants?

They are in week 2-3 of flowering and i dont wanna spray them.

 

[ozzieAI]

I use neem oil to deal with rust and spray up week 6 without any issues. 3ml per litre works for me

 

[THC123]

I have greencure that should also work no? It is totally odorless

 

[ozzieAI]

i have no idea what greencure is. from my experience pure neem doesn't leave any smell or taste and stops rust in it's tracks

rust will damage the leaves and will only affect the buds once the damaged leaves enter into the buds then i tend to get damage to my buds. this process can take a few weeks to occur...

 

[ozzieAI]

just looked up greencure should work...but again i have no experience

check here: https://www.icmag.com/ic/showthread.php?t=215085

 

[THC123]

This is rust right?

 

[soil margin]

I would start considering other possibilities honestly. Rust is a fungi that goes after sick/unhealthy plants. Very rare to see it just pop out of nowhere into a clean, healthy garden. If it is rust you should be able to rub the sick part of leaves and get rust on your fingers.

I have seen nutrient lockout and salt buildup cause issues that look similar to this. Perhaps flush your plants well with clean PH'd water for a few days and see if the problem subsides. Take some pictures of the bottom of the leaf as well that would help to see whats going on.

Your plants also seem to match the description of phosphorous deficiency I found on another site, one other thing to consider:

"Deficiencies will show in older leaves first. Leaves turn deep green on a uniformly smaller, stunted plant. Leaves show brown or purple spots."

 

[Easy7]

Rust will attack the healthiest of plants as much as the weakest. That is not rust from what I know. I went into a wheat field once, there was rust all over the wheat. It's called wheat rust, and it came home and got all over my small 250w plants. I killed them because there was no point in fighting something so damn horrible.

Wheat rust spreads like wildfire, it will leave rust on your fingers when touched....awful awful stuff.

 

[soil margin]

Rust will attack the healthiest of plants as much as the weakest.

It can but it's very rare from my experience. The only time I've seen it on healthy plants is because of ridiculous humidity and poor ventilation/air circulation. You would probably see other problems as well if plants were in an environment like that.

 

[THC123]

actually there is no powder of any kind involved, just brown necrotic round spots

I dont get anyhthing on my fingers

 

[Easy7]

I figured that from the pics. To me, and I am no expert on nutrient imbalances, it looks like nutrients got on the leaf. Are you suing chems?

 

[THC123]

We figured it out, it is brown blight or brown leaf spot

I treated them with greencure now. I can treat my moms with a chemical fungicide.

I will also treat the leaves of the flowering plants in the greenhouse with a washing cloth and the chemical fungicide so i dont get anything on the buds

Hopefully I will be able to harvest this way.

The most important thing is that my indoor moms dont get killed because of this as i have kept them for so long

 

[MynameStitch]

does it wipe off or leave like a stain looking like when you wipe it?

 

[ozzieAI]

that looks similar to what i get THC and as stated earlier pure neem oil stops it in its tracks. to help stop it spread you can also pick the affected leaves and remove from the grow area. i don't bother doing this as rust is throughout the area i have been growing my plants for years. yes you can spread it to other plants...if the conditions are right for it to grow...

good luck

 

[THC123]

does it wipe off or leave like a stain looking like when you wipe it?

no just brown spots that seem dead and the spots get bigger and are often circular in shape

 

[MynameStitch]

does not sound like rust... rust can be wiped off if I remember right..... I will double check....
How are your plants doing now?

 

[ozzieAI]

nah rust doesn't wipe off...

 

[THC123]

yeah but if i think about it it cannot be rust as i treated them preventively with a anti mildew/rust fungicide just before flowering so it has to be something else like brown blight-leaf spot

 

[ozzieAI]

you could be right there THC...but they can both be treated the same way: http://www.colostate.edu/Depts/CoopExt/4DMG/Pests/Diseases/leafspt2.htm