VPD? Mosaic Virus? Just curious....

hydrolyzed

Active Member
Day 28 of flower here....all of my 10 plants have what looks like either a Mosaic Virus, or what I have seen in other pictures as a VPD problem.

I know VPD is an issue right now in my room, it runs at 86F @1300ppm CO2, and the humidity is supposed to be (going by the VPD chart) between 75%-85%...it's at 50% with the AC off, and drops to 40% when the AC kicks on. At night, the humidity goes up to 90+%, temps still 86F.

I think I'm going to get a humidifier to bring day time humidity up to 70%, and a dehumidifier to bring night time humidity down to 50-60%.

I was always taught that warm humid environments are perfect for mold and bud rot to set in and to get humidity as LOW as possible past the halfway point in flowering when you have buds densing up...also that very dry environments make the plants try and protect itself from drying out by producing more Trichomes.

Is this just old, outdated information? Stuff is changing every few months in this hobby now so I never know if what I read last is still the way we are doing things!!

I have gotten bud rot in a few grows here before when the humidity was about 70% and it got too hot....and now I'm being told, for VPD reasons, to put my week 5 flowering plants in 80% humidity 86F every day.....it worries me!

Thanks
 

Attachments

mike4c4

Well-Known Member
you need to get the humidity down thats all there is to it. day and night. yes day to because one leaf can lay on another and there it starts again,one drop of water on a bud and so on.
 

jondamon

Well-Known Member
I've seen issues like this before.

I've had a couple of leaves do this.

When I noticed mine I upped the Ca intake of my plants and the problem seemed to halt at just the effected leaves.


Some say TMV, others say broad or russett mites, others say genetics.



Can't really answer the RH question other than I keep mine below 55% and above 35%.

I do know that when elevating levels of Co2 the humidity should be a little higher to aid transpiration and photosynthesis so that the plant can utilise the extra available Co2 and actually make good use of it.

Does the VPD chart allow for plants that are prone to botrytis?



J
 
Top