Heat stress

[blanchdave]

the tallest of my plants start showing some slight signs of heat stress on some of the top leaves a few days ago.......

I've installed more fans and have been keeping an eye on her for the last few days and it doesnt seem to be getting any worse.

Heres my questions:

1. Is it ok to just leave her be as long as it doesn't get to bad ?
2. What exactly does heat stress do to the plant ?

Thanks

[dankfest999]

I dont know what exact effect heat stress has on the plant, but i can tell you one thing for sure:

Adding fans does not lower the temperature of the room.
When the fan blows on your skin, it feels cooler, but this is an illusion--- in exactly the same way that the outdoor temperature might be 20 and the windchill makes it feel 0, but the temperature is nevertheless 20... so blowing air on the plants will not have a strong enough effect to lower the room temp. (still a good idea to use your fans, though, for other reasons)

Also, there is a difference between general heat stress and light burn. If your plants are too close to the lamp, they effect will appear to look like a burn, almost as if it were caused by flame or something. You would definitely notice if you had this problem.

General heat stress means that they are not too close to the light to be burned, but that it is simply too damn hot in the room (above 80,85). I'm not sure what the effect of this is, nor do i know how it manifests in the plant... but i can tell you that it will stunt their growth for sure.

[blanchdave]

thanks for the reply,, and well explained !!!

I think its stress and not burn......so to lower the temps should i jus add more intakes or exhausts ? the 1's im using at the min for intakes are just pc fans.

[motorheed]

intake & outake fan mate

have the intake low down & your outake up top

all the best

[Hashmouf]

You must have a fresh air intake and have a place for old stale air to escape to or temps will continue to rise in the entire room. Take readings of temp directly under the light as well as a area in the room that is not directly near the light, if they are the same you have a problem. The ambient temp of your room should get no higher then 90 degrees Fahrenheit if this occurs you need better ventilation intake and exhaust. Plants can handle heat issues much better if they have a steady supply of CO2 but if all the CO2 is depleted and the same stale air is circulating around the room you basically have a oven and are baking your plants. The room must have some sort of ventilation, plants need fresh air and old air must be removed to keep temps and CO2 levels at a suitable level.

One of the main effects of heat stress is plants turning Hermie, heat stress is a main cause of this more then any other factor. Control your temps, supply a fresh air source and let old air out at least twice a day and any other problems will be avoided. good luck