Interesting NC State article about germination temperature.

[CaptainAubrey]

I found this article interesting because it reduced my tobacco ignorance 1 part in an Avogrado's Number of parts. Not that the knowledge gained was small but that my ignorance is vast.

This is too late for southern hemisphere and too early for northenrn but it talks about the importance of letting the sown seed temperature vary from around 68 to 86 between night and day. Mr Duh was wondering why Inkbird had to complicate things by having variable hysteresis in their temp controllers. So dummy me kept the range real tight around 80 degrees for my grow box heated pad plants and I wondered why those in the north window did better. So here is the link for that article:

Germination temps

Another from NC State on flue curing:

2023 Flue-Cured Tobacco Guide

General tobacco growing info from NC State:

NC State Tobacco Grower's Information

I feel like some greenhorn running in here thinking he has found the Holy Grail when I am sure this info is probably on the site but I have not found it.

Now I need to go fix the furnace. Oh joy.

John

 

[deluxestogie]

Interesting data. The germination temp article is specifically discussing commercially pelleted tobacco seed. (Each seed is individually coated with a clay formulation at a factory.) While the theory of requiring diurnal temp variation is the point of the article, as well as hazardous max temps, the data provides no comparison of germination at diurnally varied temp vs. a control group of germination at a constant temp. [I think. There appears to be a lengthy blank area on the page display.] My suspicion is that the benefit of temp variation may be more noticeable with pelleted seed than with naked seed.

My own experience has been with germination in my sun-exposed, enclosed back porch. So there is always some diurnal temp variation during my germination.

Bob

 

[CaptainAubrey]

Good update, Bob. I can't say about pelleted vs non, I only studied inorganic chemistry and only one semester of college biology. I will ax de wife. At the core I think that particular need of the seed would be the same. Would like to compare but have no pellets.

So another job for the kiln, the kiln I am trying to convince the wife would be a good place to culture her yogurt, except in tobacco curing/fermenting season. But then I might need to buy another milk cow. Hmmm.

I am thinking about when seeds are started and the temps can still get too low. I think I will set the on temp to 70 and off to 84. Then maybe add some thermal mass like plant trays with sand or wet sand. For heat I will use something undersized like a grow mat and experiment to see if I can get a slow temp cycle. Maybe open the air vents so there will be some outside air infiltration and influence. Further improvement just jumped into my pea brain. Use the Inkbird as main temp controller but when it can't handle a low outside ambient a KT100 could be set to come on at 68 and raise the temp with more substantial heaters and raise the temp to the same cutoff. Having the seeds/seedlings sitting atop one of the thermal masses would slow the temp response.

Why would I do all of this? It would be IN - THE - NAME - OF - SCIENCE!. No, not really, though I do hope my methods would be rather scientific. The real reason is the same reason I am trying to grow tobacco; to learn, to tinker, to experiment, and maybe enjoy the sublimation of my efforts. And all of that is FUN. The difference between men and boys is the price of their toys. I will go sit quietly in my corner now.