Day/Night Temperatures

Originally Posted by Cloudz2600

More than a year later and no links, seems legit lol. Thanks for bumping this thread universe, gonna have to go with UB on this one.

Maybe we could do something about that.
Even though this document is on chrysanthemum's. The information that is contained inside relates to other plants. I've been searching the web for an document to post up and the best I can find is here http://aob.oxfordjournals.org/content/90/1/111.full.pdf

It all has to do with internode and stem length. also has if I remember correctly from my studies, anything drastic change within 10-15F WILL show symptoms of mild shock its system. same goes for the root system when you shock it from either warm or cold water.

Going back to what Uncle Ben had said. I would strongly disagree.
Plants don't do so well when the root system is cold. Matter of fact anything under 50-60 and the root systems metabolic uptake starts to cease up. When I say stay within 10-15F from your day/night, Even human's burn their own bodily nutrients to get the temperature to the level we need it at. Example: its 950F out and your you drink a cup of ice cold water, your body will now burn calories to get that ice water to the temperature your body is set at. So that being said, if your day is 75F and your night is 55F your plants priorities will be set to adjusting temperatures so it can run it's photosynthetic process and NOT on "growing" or "flowering" like you want them too.

If anyone has any questioned on this. just google "biochemical processes's of plants" and look into plants mechanisms for heat and cold tolerance and read about a plants metabolism when related to hot/cold.

Hope We Helped

I have very little fluctuation with my temps..75-77 lights on..70-72 lights off. My plants thrive. Grows that Ive had before with lower dark period temps had bud rot issues, especially bushy indicas..so I like to keep it low 70s.

Growing purple kush currently. Temps have been much higher at night this round compared to last grow over the winter. Most of my plants with major temp variations turned purple 7 weeks in flower. I'm there now and there is no purple on any. They look good but, not the purple color going on that so many like. Including myself. Not that color is what it's all about. Let you all know on the potency.

Originally Posted by BustinScales510

I have very little fluctuation with my temps..75-77 lights on..70-72 lights off. My plants thrive. Grows that Ive had before with lower dark period temps had bud rot issues, especially bushy indicas..so I like to keep it low 70s.

Hey, wonder if I can give some advice. Temps and your relative humidity have a large roll to play in the whole "botrytis" factor. BUT you may be having issues with air circulation. Do you currently have fans running? I mean blowing into your plants that is. If you haven't got oscillation fans to circulate the air and to blow cool air onto your plants, you WILL suffer bot rot issues. Your temps seem to be perfect, but you may need to check your humidity or check the air circulation. anything over 80 and you might have issues. But with your temps, I don't see why this has happened in the first place

Originally Posted by Uncle Ben

High night time temps eat up carbos that were manufactured during the day to the process of respiration versus cellulose production. That's the science.

Me? I'd rather get fat dense colas knowing that I had given my plants a 20F drop in day to night time temps. All fruit bearing plants produce superior quality fruit with a large swing in day to night temps, especially wine grapes. I'll take a Cab that ripens with 55F temps during late ripening over one that has high night temps of say 72F.

Experiment, that's the only way you learn.

dang... ive been keeping my nighttime temps around 75F. thought it might be too cold for it since the lights are off and the intake air is quite cold.

Originally Posted by tommyromano

Maybe we could do something about that.
Even though this document is on chrysanthemum's. The information that is contained inside relates to other plants. I've been searching the web for an document to post up and the best I can find is here http://aob.oxfordjournals.org/content/90/1/111.full.pdf

It all has to do with internode and stem length. also has if I remember correctly from my studies, anything drastic change within 10-15F WILL show symptoms of mild shock its system. same goes for the root system when you shock it from either warm or cold water.

Going back to what Uncle Ben had said. I would strongly disagree.
Plants don't do so well when the root system is cold. Matter of fact anything under 50-60 and the root systems metabolic uptake starts to cease up. When I say stay within 10-15F from your day/night, Even human's burn their own bodily nutrients to get the temperature to the level we need it at. Example: its 950F out and your you drink a cup of ice cold water, your body will now burn calories to get that ice water to the temperature your body is set at. So that being said, if your day is 75F and your night is 55F your plants priorities will be set to adjusting temperatures so it can run it's photosynthetic process and NOT on "growing" or "flowering" like you want them too.

If anyone has any questioned on this. just google "biochemical processes's of plants" and look into plants mechanisms for heat and cold tolerance and read about a plants metabolism when related to hot/cold.

Hope We Helped

dammit... i dont know who to listen to. Uncle Ben said a 20F drop is good and high night temps eat up carbos. but you say it will shock the plant. guess i gotta go research myself. hopefully marijuana plants is just like any other plants when dealing with temps.

Originally Posted by cannav0re

dammit... i dont know who to listen to. Uncle Ben said a 20F drop is good and high night temps eat up carbos. but you say it will shock the plant. guess i gotta go research myself. hopefully marijuana plants is just like any other plants when dealing with temps.

For starts, I wasn't referring to temps in the root zone. Yes, very cold temps at the root zone will impede normal processes.

Again, if you stray far away from mother nature's drills it will show up in various ways. If a plant is using the carbos it made during the day to excessive respiration then production or plant health will suffer. I could care less about internode length on mums.

Temperature

Most plants tolerate normal temperature fluctuations. In general, foliage plants grow best between 70 degrees and 80 degrees F. during the day and between 60 degrees to 68 degrees F. at night. Most flowering plants prefer the same daytime temperature range, but grow best when nighttime temperatures range from 55 degrees to 60 degrees F. Lower nighttime temperatures help the plant: recover from moisture loss, intensify flower color and prolong flower life. Excessively low or high temperatures may cause: plant stress, inhibit growth, or promote a spindly appearance and foliage damage or drop. Cool nighttime temperatures are actually more desirable for plant growth than high temperatures. A good rule of thumb is to keep nighttime temperatures 10 to 15 degrees lower than daytime temperatures.

http://aggie-horticulture.tamu.edu/o...-and-humidity/

I consider cannabis just another annual foliage plant. Also, it's a di-cot.

I think you're splitting hairs as this issue is just one of many regarding general botany. I've been growing for decades. A night temp of 10 - 20F works very well. They just don't "thrive", they grow like weeds. See this thread as an example. I don't think there are many (soil or hydro doesn't matter) that can start a seed and 3 weeks later have a plant ready for flowering. Here's one such journal - http://www.rollitup.org/general-mari...t-pruning.html

UB

My best friend recently went through this issue. He was running his lights at night and turning them off during the day. Everytime I would go visit them I would tell him, something isnt right man. I didnt know at the time that he wasnt turning his ac on during the day to cool it down. When I finally asked the right question (weeks later) it was of course too late for that batch. He fixed the issue after and the difference in the batch he has going currently and that last batch is 100% night and day difference.

You better believe a drop in night temps is important.