Some Clues About Early Budding

[deluxestogie]

Perhaps we have clarified a bit about the timing of tobacco plants beginning to flower. This possible insight comes from a study of the weed, Arabidopsis thaliana, which has replaced tobacco in basic botany research. [Nobody will fund anything having to do with tobacco these days.]

The revelation is the result of the stunningly unremarkable discovery that indoor artificial lighting and temperature control are not natural. Doh! We now have a couple of decades of laboratory data on Arabidopsis, including all sorts of detailed genetic and enzymatic interactions and effects, but nearly all of the research was undertaken using the very same "standardized lighting and temperature" conditions. That makes for tidy comparisons.

In the discussion in the link below, a small number of adventuresome researchers finally got around to comparing indoor-grown and outdoor-grown Arabidopsis. They looked at the activity of a particular gene that is known to influence the transition between vegetative growth and flowering, then looked at the possible causes for the differences they documented.

https://phys.org/news/2018-09-morning-gene.html

I'll just get directly to the punchline:

• standardized "daylight" fluorescent lighting has a different spectrum from sunlight, and this influences the amount of activity of a gene that can trigger flowering
• daily cycling of growing temps--to mimic outdoor conditions--results in a different time of day during which this gene is most active

In my own tobacco seedling production, the trays are on wire shelves on my back porch, and exposed to natural sunlight and day/night cycles. Although the porch temperature is not the same as outdoor temp during the early spring, it does cycle somewhat during the day/night cycle. I have seldom experienced significantly early tobacco blossom formation.

So, no direct answers here. But some of our confusion may be the result of the complex interactions between

• different light spectrum
• different day/night lighting cycles
• different ambient temperatures
• different ambient temperature day/night cycles

And everybody's seedling production conditions are different from everybody else's.

Bob

 

[OldDinosaurWesH]

Interesting, if somewhat confusing.

I germinate and start my seedlings in a south facing window using natural light and natural daily light cycles. I supplement the natural light with florescent bulbs that I have set on a timer meant to imitate the naturally available light cycle. The major difference in my system and a totally natural light / temp. system is my use of a heat pad which maintains fairly constant temp. of about 70 degrees.

So I guess I'm mixing the natural with the artificial in regards to seedling production. As to how this regime ultimately effects the bloom cycle in my tobacco is difficult to ascertain.

Based on my three years growing experience, most of my tobacco types seem to bloom on a fairly consistent basis. Starting in late July and through August seems to be the prime blooming period for most types. That being said, each individual type seems to have it's own cycle with some blooming earlier and others blooming later. Some blooming really late.

I'm still unsure how the FT gene fits into this scheme of things. I'm of the opinion that environmental stresses will definitely effect the bloom cycle. Other than that I'm uncertain.

All I know for sure, is that I'm lucky to live in an area where early frosts are a rare thing. Even with the latest of bloomers, I can still get some seed.

Good work Bob. You are tackling a difficult subject. Keep digging and I await your results.

Wes H.

 

[FmGrowit]

I'm going to go out on a limb here and predict the team at phys.org will make an announcement within the next 50 years that the earth is round.

 

[skychaser]

..."Arabidopsis thaliana, which has replaced tobacco in basic botany research. [Nobody will fund anything having to do with tobacco these days.]"....

I've sold tobacco seed to 3 different research groups this year. Two in the US and one in Japan. Been a half dozen others over the years. There is still a lot being done with tobacco.

I saw this article on phys.org. It's one of my favorite websites that I read almost daily. I'm not sure how this study relates to my tobacco growing, aside from finding a gene involved in flowering. All my seed is started and grown under natural light and my plants are in the greenhouse within a day or two of sprouting. Even in the greenhouse the temps fluctuate widely from day to night and closely follow the natural outdoor temps, ranging from a low of 40f (where the heater kicks on) to a high of around 85f. They are planted out at 8-9 weeks around the 1st of June. It's the same routine every year. So I don't think it is anything to do with what is happening to them in their infant stage of life.

The experiment I would like to conduct would be taking half the seedlings of several strains and planting them out as I normally would, and planting the other half in a controlled greenhouse environment where the temp and light could be controlled. About 2-3 weeks after planting I would put shade cloths over the control group to mimic overcast conditions and drop the daytime temps to the 50's - 60's for two weeks. Then return them to the outdoor conditions the other half are experiencing and see what happens. All I need in a greenhouse with some really good A/C. Better yet would be to have 3 control groups. One gets shade cloth, one gets the temp lowered and the 3rd gets both. My anecdotal observations tell me the lower temperature would be the trigger.

Anyone wanna fund my experiment? I would make good use out of the greenhouses after the experiment is over.

 

[skychaser]

I'm going to go out on a limb here and predict the team at phys.org will make an announcement within the next 50 years that the earth is round.

Well, that's just silly. All I have to do is look out the window to tell that the Earth is flat! geez.....

 

[deluxestogie]

There is still a lot being done with tobacco.

I am being a touch hyperbolic. But even the folks that maintain the ARS-GRIN tobacco germplasm bank at NCSU (the GRIN of seed requests from yesteryear) do their damnedest to avoid using the "t" word in describing their plant genetics research. And much of the rush to using Arabidopsis thaliana has been to enable research grant requests to be written without using the unfortunate "t" word.

Historically, GRIN as well as federal funding of plant genetics research in general (and in many cases the creation of Extension Services) were started, to a large extent, because the USDA officially (and correctly) recognized the need to improve tobacco production in the US, and to identify genetic resources for imparting disease resistance to commercial tobacco varieties. Tobacco was a priority to the federal and state governments back then. Now, ARS-GRIN has essentially disowned the tobacco resources, and defunded them, requiring NCSU to cough up the financial support for it.

Phys.org is the only free source I know of that aggregates the most recently published research from widely ranging fields of study. Some of it is just PR from university publicity offices, but most is the real deal.

Bob

 

[skychaser]

Graham Hancock's news link is pretty good. But it used to be a lot better. They cut back to publishing just a few new stories each day for some reason. Used to be whole page full. https://grahamhancock.com/news/

 

[CT Tobaccoman]

Interesting, if somewhat confusing.

I germinate and start my seedlings in a south facing window using natural light and natural daily light cycles. I supplement the natural light with florescent bulbs that I have set on a timer meant to imitate the naturally available light cycle. The major difference in my system and a totally natural light / temp. system is my use of a heat pad which maintains fairly constant temp. of about 70 degrees.

So I guess I'm mixing the natural with the artificial in regards to seedling production. As to how this regime ultimately effects the bloom cycle in my tobacco is difficult to ascertain.

Based on my three years growing experience, most of my tobacco types seem to bloom on a fairly consistent basis. Starting in late July and through August seems to be the prime blooming period for most types. That being said, each individual type seems to have it's own cycle with some blooming earlier and others blooming later. Some blooming really late.

I'm still unsure how the FT gene fits into this scheme of things. I'm of the opinion that environmental stresses will definitely effect the bloom cycle. Other than that I'm uncertain.

All I know for sure, is that I'm lucky to live in an area where early frosts are a rare thing. Even with the latest of bloomers, I can still get some seed.

Good work Bob. You are tackling a difficult subject. Keep digging and I await your results.

Wes H.

From when I used to work in Connecticut on shade tobacco, I remember seeing a chart in which maturity and ripeness can be ascertained by keeping track of the degree days after plants are set into the field. We never actually did this because we relied on our own experience, but I guess this is one method by which it can be done.

 

[deluxestogie]

Growing Degree Days is an interesting prospect. I'm not sure how that would clarify the sometimes wildly differing blossom times from one variety to the next, without variety-specific data.

If anyone is interested in giving it a try, here is an on-line growing degree day calculator: http://www.greencastonline.com/growing-degree-days/home You just plug in your zipcode (US), a base temperature, and select a date range.

The calculation requires a "base" temperature at which a particular species of plant begins to actively grow. Most common ones use 50°F. I was unable to find one specifically for tobacco. So I guess 50°F is a reasonable guess.

I don't know of any guidelines for tobacco, so your mission, should you choose to accept it, is to crunch the numbers, and see what you come up with.

Bob

 

[CT Tobaccoman]

Growing Degree Days is an interesting prospect. I'm not sure how that would clarify the sometimes wildly differing blossom times from one variety to the next, without variety-specific data.

If anyone is interested in giving it a try, here is an on-line growing degree day calculator: http://www.greencastonline.com/growing-degree-days/home You just plug in your zipcode (US), a base temperature, and select a date range.

The calculation requires a "base" temperature at which a particular species of plant begins to actively grow. Most common ones use 50°F. I was unable to find one specifically for tobacco. So I guess 50°F is a reasonable guess.

I don't know of any guidelines for tobacco, so your mission, should you choose to accept it, is to crunch the numbers, and see what you come up with.

Bob

I'll have a look through my stuff and see if I can find the degree day paper for tobacco that we received from the Ct Ag Experiment Station. The idea was to judge when different primings would be ripe

 

[skychaser]

I'll have a look through my stuff and see if I can find the degree day paper for tobacco that we received from the Ct Ag Experiment Station. The idea was to judge when different primings would be ripe

I don't think degree days affect tobacco as much as some other crops, but there definitely is an effect. We had a summer a couple years ago where the daily high was 5-10 degrees below average for most of the summer. It was nicer for us, but everything we grew was 2-3 weeks later in blooming and ripening, including the tobaccos. I've never seen any numbers on tobaccos. I'd be very interesting in seeing some info on it. But I don't think degree days, plus or minus the average, would be a cause of premature blooming. It happens too early in the season for the degree day total to matter much yet.

 

[ChinaVoodoo]

Growing degree days is also used for predicting the best times to spray for specific insects, as their life cycles are also predictable.

There is a research weather station near my house and I can get up to date GDD info. I contemplated monitoring the tobacco by it, but I think it would be too much work with as many strains as I have been growing. Maybe if I just singled out one strain.

 

[skychaser]

Growing degree days is also used for predicting the best times to spray for specific insects, as their life cycles are also predictable.

It can be used to predict the exact day some things will happen. Quite fascinating to me when I first learned about degree days.

 

[deluxestogie]

The timing of some biological processes are mostly dependent on accumulated energy input. Kind of like boiling an egg. You can hard boil it at 212°F in 10 minutes, or you can accomplish the same thing in 20 minutes at ~130°F. I would guess that both methods have nearly the same impact on your electric bill.

Bob

 

[plantdude]

My old advisor used to swear up and down that arabidopsis knew when it was spring and would germinate and grow better even though we were growing our plants in a growth chamber in the basement of the biology building with no natural lighting. It was one of the few things I think we ever agreed on. I often wonder if plants are not picking up on more environmental cues than we realize.

 

[deluxestogie]

No question. Arabidopsis thaliana is as smart as a cabbage. Too bad you were not born a generation earlier. Nearly all of that kind of university research, up to the early 2000s, was undertaken using Nicotiana tabacum. Social, financial and political pressures caused plant physiology and genetics research to abandon tobacco, so that the "T" word wouldn't appear on grant proposals and websites. (Even ARS-GRIN abandoned ownership of the tobacco germplasm bank, turning it over to a privately funded enterprise at NCSU's department of Plant Genetics.)

As to a plant "knowing", you might find Daniel Chamovitz' course, "What a Plant Knows", available on-line at Coursera.org, informative and fun. You can audit it for free. Lots of plant sensory and behavioral commentary.

Bob

Understanding Plants - Part I: What a Plant Knows

Offered by Tel Aviv University. For centuries we have collectively marveled at plant diversity and form—from Charles Darwin’s early ... Enroll for free.

www.coursera.org

 

[plantdude]

No question. Arabidopsis thaliana is as smart as a cabbage. Too bad you were not born a generation earlier. Nearly all of that kind of university research, up to the early 2000s, was undertaken using Nicotiana tabacum. Social, financial and political pressures caused plant physiology and genetics research to abandon tobacco, so that the "T" word wouldn't appear on grant proposals and websites. (Even ARS-GRIN abandoned ownership of the tobacco germplasm bank, turning it over to a privately funded enterprise at NCSU's department of Plant Genetics.)

As to a plant "knowing", you might find Daniel Chamovitz' course, "What a Plant Knows", available on-line at Coursera.org, informative and fun. You can audit it for free. Lots of plant sensory and behavioral commentary.

Bob

Understanding Plants - Part I: What a Plant Knows

Offered by Tel Aviv University. For centuries we have collectively marveled at plant diversity and form—from Charles Darwin’s early ... Enroll for free.

www.coursera.org

Thanks, I'll have to check the course out.
It's funny how anti tobacco the government became yet last month they bought millions of dollars in bonds from Phillip Morris as part of their cov19 stimulus package. Tobacco growing is still an important crop in American agriculture.
What got me into growing tobacco was a post doc who gave me a bag full of seeds from one of their indirectly gov funded research projects. The seeds sat in my seed box for years until I planted some the winter before last on a whim. They are fascinating plants to watch grow and I fell in love with them. I still have no idea what variety the lab strain of seed was/is - probably some weird GMO I just thought it was funny that it was the government that indirectly got me started on growing tobacco.

The only thing that would put me off of using tobacco as a research tool is that they are tetraploid. I've worked with wheat and a few other polyploid species before and I have to admit that simple diploid organisms are much easier to follow from a genetics standpoint.

 

[deluxestogie]

Tetraploid is double the pleasure, double the fun.

 

[GreenDragon]

A.t. does have several advantages over N.t. as a research specimen. As @plantdude noted, it has a simpler genome, a shorter life cycle (allowing for more generations per year), and most importantly, much smaller space requirements. I never liked working with it though.

 

[GreenDragon]

Also, for many plants, flowering is also influenced by the ratio of Red to Far Red frequencies of light. This ratio is affected by overhead and nearby plant growth, but it also varies by the season due to the angle of incidence to the sun. You can induce or prevent flowering of some species in the lab by manipulating the hours of sunlight and exposing them to a burst of a specific (red) wavelength of light after the main lights are turned off.