Possible mildew question on behalf of a greenhouse grower...

[qpwoeiruty]

I gave someone I know a couple of photoperiod seeds for their greenhouse, I only really use autos. It's their first grow and it looks good at the moment. I went round to see them the other day and they had some powdery stuff on the leaves. I've never had that as an issue before and it doesn't seem to be hurting them too badly at the moment at least but I was wondering what it was and if it's going to be an issue. The whole greehouse seems to have some degree of stuff on it and I think it might be mildew.

 

[Canuck147]

Look under the leaves - fungal gnats - also known as 'The Borg'.

 

[MeEasy]

When I zoom in I see little black guys that look like spider mites but I don't see any webbing. I've never seen the Borg that Canuck147 is talking about but with no webs he's probably closer than I am. I can't zoom enough to make out the black guys for facial recognition lol

 

[qpwoeiruty]

I'll get a pic of the underside next time I swing by there

 

[qpwoeiruty]

And they would cause a powdery stuff on the leaves?

 

[MeEasy]

Here's a link with some pictures of them. I'm not sure that it is from your picture it looks like it could be

https://www.growweedeasy.com/cannabis-plant-problems/how-to-get-rid-of-spider-mites

 

[homegrown]

Ya..thats not WPM..you got bugs.

 

[CaptainWiese91]

Thrips only In the early stage is my opinion.
could also be spider mites, they only develop the web in the late stages because the colonies are getting to big for the leaves.
Spider mites in early stages is possible without seeing any web at all..

 

[MeEasy]

Thanks that's good to know I've only seen spider mites once. My brother in law works for a greenhouse that grows hemp he helps me out quite a bit but two or three years ago they ended up with them and I went over because I was curious and there were webs all over the bottom half of three different plants. Obviously they had been in there for awhile so to know that they won't have webs in the beginning is good to know.

 

[CaptainWiese91]

I have them in my veggie garden. But the alcohol kills them right away.

 

[qpwoeiruty]

Could you describe what alcohol you use and how you use it... For example isopropyl alcohol or grain alcohol, whether you dilute it and I'm assuming you spray it.

 

[CaptainWiese91]

Isopropyl alcohol, bought in a garden store. 60% alcohol and 40% water.
Yea I spray it. Just before lights are out or the sun is down.