Growing Methods vs. Nicotine Level

[deluxestogie]

I stumbled into an article in an 1878 issue of Scientific American. (It's via Google Books, which did not allow text capture, so please forgive my use of an image of the 134 year old text.)

Another interesting finding from more recent research is that in plants allowed to develop full seed heads, the nicotine content of the leaf is 20%+ lower than if the plant is topped.

In general, to produce tobacco with lower nicotine:

• plant closer together
• do not top the plant
• allow all leaves to grow
• harvest the leaves earlier than full ripeness (beware of difficulty color-curing)

.
The opposite would be true for increasing the nicotine level:

• plant at full spacing
• top the plant
• remove upper leaves when topping
• harvest the leaves as late as possible (yellow-ripe is already color cured!)
• select the upper-most leaf for highest nicotine

Bob

 

[Jitterbugdude]

Ah, to have a portable nicotine counting machine! Last year I harvested a small portion of my 15 different varieties at 1 week, 2 week and 3 weeks after topping them. I harvested the rest as you traditionally would ( starting at about 3 weeks after topping). So far I have not been able to tell any difference in nicotine levels. Since other factors are involved with nicotine levels, such as nitrogen content of the soil, heat, rainfall etc I'm not so sure its as simple as the list from the above article. I would love to know how they determined the nicotine levels. It was 1878 after all.

On the other hand, it makes sense that planting more plants in a given area would reduce nicotine levels since there are now more plants competing for the same amounts of nutrients. It also makes sense that harvesting them earlier would have the same effect.

Randy B.... bewildered about nicotine

 

[deluxestogie]

It was 1878 after all.

Scientific American, though always directed at an educated audience, has never been a scientific journal as we would understand one, so methods and data are seldom discussed. By 1878, however, quantitative analytic chemistry was fairly well developed. I guess that we can read the quote from SA above as if it had said, "all other conditions being equal..."

With regard to just the topping, though reported here only in Samsun:

Nicotine %

• Bright flue-cured: 2.76%
• Samsun Sun-cured Not Topped: 1.60%
• Samsun Sun-cured Topped: 4.32%
• Samsun Flue-cured Not Topped: 2.29%

Bob

 

[FmGrowit]

Take this for what it's worth. I was interrupted four times while trying to understand it. It's pretty technical writing, but I think it says suckers do not produce higher amounts of nicotine than the original plant, but regenerated roots will produce higher amounts of nicotine in the plant tissue generated from the regenerated roots.

Tobacco is a perennial, so in theory, you should be able to keep the root stock alive (over-winter like a cana lilly) and use that root stock to grow new plants. Those plants should have a higher degree of nicotine than the plant tissue from the year before.

Again, I think that's what this report says.

Take a look for yourself though

 

[FmGrowit]

Here's a study from China

It is believed that the nicotine concentration in tobacco is closely correlated with the amount of nitrogen (N) supplied. On the other hand, N uptake mainly occurs at the early growth stage, whereas nicotine concentration increases at the late growth stage, especially after removing the shoot apex. To identify the causes of the increased nicotine concentration in tobacco plants, and to compare the effects of different ways of mechanical wounding on nicotine concentration, field experiments were carried out in Fuzhou, Fujian Province in 2003 and 2004.

Excision of the shoot apex had almost no influence on N content in the plant; however, it caused dramatic increases in nicotine concentration in leaves, especially in the middle and upper leaves. An additional increase of the nicotine concentration was obtained by removal of axillary buds. The wounding caused by routine leaf harvests, however, did not change the leaf nicotine concentration, and neither did reducing leaf harvest times. The present results revealed no direct relationship between N supply and nicotine concentration in tobacco leaves, and indicate that not all kinds of mechanical wounding were capable of stimulating nicotine synthesis in tobacco plants.

Since nicotine production is highly dependent on the removal of apical meristems and hence on the major sources of auxin in the plant, and application of 1-naphthylacetic acid onto the cut surface of the stem after removing the shoot apex markedly decreased the nicotine concentration in different leaves and the total nicotine content in the plant, the results suggest that decreased auxin supply caused by removal of the shoot apex as a kind of mechanical wounding might regulate nicotine synthesis in the roots of tobacco plants.

Wang SS, Shi QM, Li WQ, Niu JF, Li CJ, Zhang FS.


Key Laboratory of Plant Nutrition and Nutrient Cycling, Ministry of Agriculture, China Agricultural University, Beijing 100094, China.

 

[FmGrowit]

[h=1]THE GROWTH, NICOTINE AND PHOSPHORUS CONTENT OF TOBACCO GROWN AT DIFFERENT SOIL TEMPERATURE, MOISTURE AND PHOSPHORUS LEVELS[/h]Growth, nicotine and phosphorus content of tobacco, as influenced by soil temperature, soil moisture and soil phosphorus levels, were investigated by growing the flue-cured variety Hicks in a combination of three soil temperature, four soil moisture, and three soil phosphorus treatments.Soil temperature of 22 °C. and soil moisture of 75 per cent of available moisture appeared to be the best for the over-all growth of tobacco.

The over-all growth was a little lower at the 30 °C. soil temperature than at the 22 °C. temperature while at the 14 °C temperature it was very poor. Nicotine and phosphorus content in leaf tissue decreased with decreasing soil temperature. A decrease in soil moisture decreased the growth but increased the nicotine content of tobacco. Phosphorus content was influenced little by soil moisture treatments. Low soil moisture treatments were more detrimental to growth of tobacco at the low soil temperature than at the higher ones.

Phosphorus produced growth responses at the low soil temperature only. Nicotine content was not influenced by soil phosphorus treatments. Phosphorus applications increased the leaf phosphorus content. At the 14 °C. soil temperature there was an increase in leaf and stalk weight and leaf area with added phosphorus while at the 22° and 30 °C. increases with soil temperature were very small. Stalk weights increased with increasing phosphorus applications at the higher but not at the lower soil moisture levels. The growth was decreased more at the soil temperature of 14 °C. and soil moisture treatments of 25, and near 0 per cent of available moisture than at the soil temperature of 22° and 30 °C. At the low soil moisture phosphorus applications decreased root growth while at the higher soil moisture treatments this phosphorus effect was reversed.

Canadian Journal of Plant Science, 1960,

 

[FmGrowit]

This article seems to suggest the nicotine levels in the plant are determined within hours of germination. It all goes back to what we've pretty much already know though. Start your seeds in warm soil and keep the seedlings moist. Promote strong root systems and the plants will take care of themselves after that.

Very interesting read

 

[deluxestogie]

That last article, on the alkaloid content of germinating tobacco seed, is both interesting and puzzling. Thank you for the link. What would be significant is if the nicotine level of the germinated seed correlated in some way with that of the mature plant leaf. This research did demonstrate that ~80ºF is the sweet spot for tobacco seed germination. Their untested and unsubstantiated assertion that the "alkaloid composition" of the seed reflected that of the mature plant seems to be merely indicating that the ratio among the four alkaloids that were measured is the same as other researchers have reported in the mature leaf. They discuss no method or result that would indicate that high nicotine in the 144 hour old seedling leads to a comparably high nicotine in a plant matured from that seed.

I read through the 3 page article several times, hoping to understand what it is that they were attempting to clarify. I believe their goal was to demonstrate that nicotine is contained within the ungerminated seed of N. tabacum (others had already shown it to be present in the seed of N. rustica), and that the decrease and subsequent increase of its level (and the levels of the other three alkaloids) during germination are consistent with the assertion that tobacco alkaloids serve an active role in plant metabolism, rather than simply being a waste product or byproduct of that metabolism. Their demonstration that alkaloid production in the seed radicle was optimum at ~80ºF shows that alkaloid production is maximized at the same temperature as optimum metabolism.

I give the authors a B for effort, and a C for clarity and write-up.

My conclusions from laboring over their paper are:

1. Seed will germinate best at ~80ºF.
2. Seedlings will have maximal nicotine when germinated at ~80ºF
3. No correlation has been demonstrated (in this paper) between seedling nicotine level and mature leaf nicotine level

Bob

 

[FmGrowit]

Yes, I used to very strongly promote 70ºF soil temperature for germination, but most data suggests 80ºF is the optimum temperature. I do know from personal experience that tobacco seeds will germinate at 70ºF in less than 48 hrs, but I'm sure seed age would affect those results.

These are all just a bunch of recipes for a similar dish. Take the best pieces and parts from all of them and create your own recipe...season to taste.

 

[taxedenuf]

Hi Guys
I've been thinkin about gettin a gadget like this just to see where i'm at with my baccy.I smoke alot so never really notice a buzz but possibly my baccy has no buzz.

 

[deluxestogie]

Yes, I used to very strongly promote 70ºF soil temperature for germination, but most data suggests 80ºF is the optimum temperature. I do know from personal experience that tobacco seeds will germinate at 70ºF in less than 48 hrs, but I'm sure seed age would affect those results.

Of course, for most home growers, the germination temperature is regulated by a combination of spare light bulbs and hamster wheels. Germination heat mats [~$30 per standard 1020 tray] raise their temp to 10ºF above ambient, more or less, unless they are attached to an additional thermostat [~$30-$50 for one that will control multiple mats]. Since we know that germination falls off rapidly as the soil temp approaches 90ºF, care should be used in trying to keep the soil at 80ºF by haphazard means. (In the study discussed in my previous post, they germinated the seed on filter paper in a petri dish located inside a temp controlled chamber.)

I guess that aiming for 70-80ºF might provide a comfortable margin for DIY germination. If you have a room that's already regulated to 70ºF, it seems like it should do just fine for germination. Much below that, it would need supplemental heat.

That same study exposed the seed to 8 hours of intense light prior to beginning the germination, and none during germination. While we've discussed whether or not tobacco seed needs that light, my overall impression from multiple sources suggests that the fresher the seed is, the more likely it is to exhibit photo dormancy, and need the light treatment. That said, I don't know how fresh is that fresh. I would imagine that attempting to germinate seed that was harvested only a couple of months earlier than the planned germination date would benefit from it, and that two year old seed would not. March germination of last August's seed is anybody's guess, though I suspect that it may not require light until the cotyledons emerge.

Bob

 

[BigBonner]

From my use of the tobacco soil . I put moistened tobacco soil in a plastic jar then add raw seeds into a plastic conatiner close the lid shake the jar mixing all the seeds through out the soil . they will germinate all through out the soil .After they germinate I pour them out on a flat pan then plug them into my float trays .

Exaple , I just germinated several varietys of seeds in my bed room next to a heater at about 75 degrees . They all germinated within four to five days to about a quarter inch long . No atrificial light and there is a lamp beside the bed and corner . No lights were left on and curtains was closed . Seeds germinated through out the soil .

My samsun came up in just a few days ottoman and bursa was next the ones that took the longest was perique and Ct Broadleaf .All the seeds were put in the jars at the same time .
I was just checking to make sure my seeds germinated ok before Im ready to use them .

 

[BarG]

I like that, Keep it simple stupid! [kiss it]. A quote from a famous american navy seal Dick Marcinko. The First head of seal team six, { where was 1-5] The ruskies couldn't figure that out. Back to seeds, do you separate with or without water to separate plants roots, when I plant in box of soil roots are so well established I have trouble separating without a bowl of water to keep from damaging roots?

 

[BigBonner]

BarG

When the seeds germinate and are about a quarter inch long , I just dump out the entire soil and pick up the seedlings one by one . In this type of soil it will fall apart easily and then put the seedlings into trays just like plug tobacco plants
Plug tobacco plants come in a float tray with tiny plants and I think it was 288 plants per tray its been so long ago I just remember exactly . They are tranfered from those trays to the 200 or 250 cell trays . This method was easily done .

I like that, Keep it simple stupid! [kiss it]. A quote from a famous american navy seal Dick Marcinko. The First head of seal team six, { where was 1-5] The ruskies couldn't figure that out. Back to seeds, do you separate with or without water to separate plants roots, when I plant in box of soil roots are so well established I have trouble separating without a bowl of water to keep from damaging roots?

 

[dkh2]

Man that is a good way to do it.
Now why didn't I think of that ?

 

[SmokesAhoy]

Well I've noticed my tobacco being very weak, thank you for this thread. Based on this I will germ in may and plant in june. This might t have been my problem as I started in february last year so the max germ temp would have been 50•f

 

[FmGrowit]

Smokes,

You might want to start them a little earlier than that. A heating pad would work fine or electric blanket, maybe a crock pot. Even if you use a cardboard box, try to start the seeds earlier than May. Maybe just have Larry send you some.

 

[Daniel]

I did a little experimenting with germination temperature last year. It was not strictly controlled but was done indoors. I found that my seed germinated best at 80 degrees minimum. Lower temperatures by even 10 degrees seemed to make a noticeable difference. Higher temperature, as high as 90 degrees, did not seem to make any difference and possible slightly lower germination rate. I recall last year that some comments where made about not cooking seed with the higher temperatures. It is my suspicion that at 90 degrees I may have experienced some damage to the seed at the very least.
I do have the ability to build an incubator that can keep temperatures very constant and humidity stable. I still think it woudl be beneficial to experiment with germination temperatures. It is my basic principal that it is impossible to grow a plant from a seed that was not started well. In practice I put a lot of time and care into that first 4 to 6 weeks before they will be planted outdoors. That care starts from the moment I spread the seed on soil.

This year I am going to change my method of starting seed in two ways. 1. I will work to keep the temperature at or as close to 80 degrees as possible. I may even set up an incubator to germinate the seed. 2. I will not fertilize while they are being grown indoors (first 4 weeks). Last eyar I started feeding when the sprouts had 4 true leaves. This year I hope to actually get a slower start with the plants and see how it effects the development throughout out the season. This may at first appear counter productive but is not necessarily so. One fact that cannot be avoided is that the plants must at some point be transplanted to the outdoors. this transition is a shock to the plant. Last year I noticed a failry long period that my plants seemed to be effected by shock. What contributed to that shock I am not completely certain. I do think it is safe to assume that transplanting alone was part of the casue. local weather was another. And that in a couple of cases our care of the tobacco helped a little. Still I believe this shock can be reduced from both direction. First by better care in when the plants are set outdoors, the care they are given once they are and by not having them growing so much by leaps and bounds when they are transplanted. It is my thinking to produce a slower growing but more resistant transplant. We will see how it all works out.