The Real Seed Company describes Mango Thai #2, a traditional Lao sativa landrace, as Cannabis sativa subsp. indica var. indica. They describe indicas as Cannabis sativa subsp. indica var. afghanica. This is from the "new cannabis taxonomy" of McPartland and Small, 2020.
Genetics impart some percentage of either C. s. var. indica ("sativa") or C. s. var. afghanica ("indica"), to produce what we call "sativa-dominant", "indica-dominant", or 50/50 balanced. A plant that exhibits strong sativa traits will typically have the best chance of natural resistance to botrytis. Some indica-dominant or indica-leaning hybrids will contain enough sativa-associated pine terpenes (incl. terpinolene) to also have natural resistance to botrytis.
A lot of people will say that the sativa morphology contributes to bud rot resistance. I haven't experienced that in my grow, and as I'm saying, my conditions are ideal to test this. Landrace tropical sativas are big plants with big, long colas. I think this morphology isn't some kind of a magic bullet against botrytis spores landing on bud surfaces, taking hold, and growing. A bud is a bud, and a cola is a cola—the botrytis organism doesn't care. But if these spores land in a trichome forest that's off-gassing anti-fungal terpenes, this lowers their ability to take hold. That's my understanding. The pine terpenes are anti-fungal.
This is a very good question. I've studied this quite a bit. My understanding is there is a defense signalling system inside the cannabis plant, and this signalling results, at least in part, in the release of cannabinoids and terpenes from the trichomes. (There may be other mechanisms inside the plant that bring chemical defense to the site of infection; however, I am not aware of those—the literature is quite complex.) Some phenotypes may have better signalling than others. So for example, it's possible that the sativas have better signalling for specific pathogens, but nonetheless, the cannabinoids and terpenes must be there and present in order to be activated.
Another good question! Well, I for one don't really care. To me it's far more important not to have to deal with bud rot which can destroy a whole harvest. That said, the presence of terpinolene and other pine terpenes may be sufficient to bring strong bud rot resistance, while at the same time myrcene, limonene, and beta-caryophyllene may also be prominent, rounding out the overall flavor. Lots of true sativas will have terpinolene and pine terpenes. Terpinolene flavor is described as sweet, citrus, floral, pine. Weedmaps describes Northern Lights #5 flavor as "sweetly tropical with a subtle herbal musk". NL5 is an indica with substantial terpinolene and pine terpenes.
As I mentioned above, yes, they originated in warm, tropical, wet India. At some point in the evolution of cannabis, some phenotypes began producing terpinolene and the other pine terpenes in the trichomes. If these helped the plant's defense against tropical pathogens, then the phenotype would survive and reproduce more than those which did not produce these terpenes.
They talk about everything BUT terpenes, and didn't explain that phenotypes of strains will have different distinct terpene profiles. They are conveying the traditional approach of recommending the planting of strains that are adapted to a specific climate, etc. What I've been driving at is, what exactly is going on that provides the natural resistance, and how can we predict that? I think the answer clearly lies with phenotypes and terpene profiles, and ultimately with terpinolene and the other pine terpenes. Simply planting strains that are adapted to a specific environment bypasses the fact that for any given stable seed line, there will be at least two phenotypes. One pheno could be sativa dominant, while the other indica dominant. Some strains produce 5 or 7 known phenotypes, each with its own terpene profile.
Selective breeding is an issue here. I've seen threads about indica landraces where the grower is quite aggravated by how "energetic" his indica turned out to be, and they often end with "I won't be growing that one again".
According to that one quote from McPartland, and your supposition that terpinolene spread from sativa strains into indicas, but you mentioned there that your research indicates the opposite.
That's interesting about the stomata, but I think it is generally accepted that leaf morphology is a solid defining factor for indica vs. sativa, in the case of plants known as "pure" indica or sativa, or 80-100% indica or sativa, or otherwise strongly dominant as one or the other. Probably not in the case of balanced 50/50 hybrids.
Which sativa strain(s) did you grow? As I mentioned before, there is no guarantee of the presence of specific terpenes in any particular sativa seed line, whether or not its labeled as a landrace or not. It's possible you could have been growing phenos that were not particularly naturally resistance to bud rot (for example), or leaf mold, and hence the need to prune for air flow. Perhaps some of your phenos were more resistant than others.
I think there are several mechanisms going on. First, the trichomes are off-gassing all the time, and especially in the daytime (due to warmer ambient temperature). This means that buds and sugar leaf surfaces are essentially bathed in a light fog of terpenes. The terpene molecules then come into contact with the fungal spores. Another mechanism is that when the plant tissues are damaged, defense mechanisms are activated in the plant (jasmonic acid signaling pathway), which I believe sets in motion the release of cannabinoids and terpenes from the trichomes. So now, the light fog becomes a heavy, sticky fog. Something like that.
There's two things going on there, one being the origins of terpinolene dominance, and the other being terpinolene dominance in modern "pure" sativas, "pure" indicas, and hybrids. Of course, to understand the origins, one needs to look at original domesticates (landraces), which are based on regional wild types.
Sorry for the confusion. I was under the impression that the presence of high amounts of terpinolene originated in Afghan Kush (indica), and then was transferred to sativas when humans bred sativas w/ indica to increase THC potency. (This is from terpene profiles of modern Afghan Kush.) The McPartland paper is saying that original sativa domesticates in India contain terpinolene, so I'm saying now that perhaps the terpinolene found its way into Afghan Kush when Central Asian growers crossed their indica with Indian sativa.
Just to be clear, when I use the term, terpinolene dominant, I'm referring to it being the dominant terpene in a terpene profile (lab test results). Some sativa phenos clearly have terpinolene dominant. Some indicas have significant terpinolene, but so far I've only seen possible dominance in some phenos of Afghan Kush and Northern Lights #5. Whether or not those phenos would exhibit predominantly indica effects, or not, I have no idea. They may have balanced 50/50 effects, or lean either toward sativa or indica effects.
Then how did they come from and still grow in the opposite environments? Indica central Asia desert/grass land and sativa south east Asia rain forest. Something is misconstrued or out of context. Sativa use all the excess water for glucose production where indica can not make quick, efficient use of it may have been what they were referring too,?
Columbian, Panama, Jamaican, Thai, Muoi, Purple afghan and Christmas tree are strain that come to mind. These were my regular yearly plants. I know I am forgetting a few, others were just one run and done. Most of them do tend to have the citrus terpenes. I didn't grow for flavor so just a coincidence and not all of them. As for air prunning I just removed stacked leaves and center leaves that received no light or air. My concern was photosynthesis not mold.
I wasn't disregarding the effectiveness of terpenes and the minor off gassing is obvious by the nose. But terpenes are the last line of defense, not your front line. Terpenes will not kill most mold spores. They can be effective on active mold. If a mold spore propagates on the leaf it absorbs the oil and dies. Another spore propagates in the same spot now that the oil is gone. They multiply and spread with some dyeing as they move across the leaf, sending out more mold and spores. This is far from an ideal way to fight it off and generally just slows the progress. Better to make conditions that spores do not like and terpenes to pick off the stragglers. Less for the mold, is more for me.
I don't know, but science is science. Another thing is that McPartland's modern taxonomic classification relies on plant and leaf morphology, terpenes, and perhaps some other factors. He makes no mention of stomata. I mean, if you have a leaf that looks like and indica leaf, and a leaf that looks like a sativa leaf, is there any reason to turn them over and inspect the stomata in order to put them in either classification? McPartland is a heavyweight scientist in the field of cannabis—if he's not mentioning this, that's saying something.
I must disagree with this, because as I say, my conditions here in wet, warm tropical Hawaii, surrounded by jungle, are such that it makes little difference whether or not you attempt to make conditions better. My HI-BISCUS pheno from Humboldt Seed Company is proof that terpenes are doing the trick. The buds are very sticky and stinky right up to harvest time when it's crucial.
I have decided to wait to see some results of my 5gal SIP bucket design and grow medium. At DAY 26 of my comparison grow, the nursery pot is still winning. I also want to wait because my usable clone stock for planting is getting kind of old in their 1 gal pots... not looking great. I have a new batch of clones (above) now just going into 1 gal pots, so I'll wait for them to grow some... but not too much. I'm getting the feeling that it's important to start plants small directly in the SIP.
If you see a large animal that looks like a bear, has bear claws, fur, build, face and fits every physical description of a bear. Why question if it is a bear? Because it is a vegetarian. Panda are not even closely related to bears.
Yeah, but that line of logic doesn't apply here, because a sativa leaf and an indica leaf are in fact genetically very similar—they are from the same genus and species, but from different subspecies. If you want to talk about bears, then a better analogy would be Grizzly vs. Kodiak. Both are going to rip you to shreds, but the Kodiak is easily identified as such because they are a lot bigger.
I'm not disputing that stomata are involved in environmental adaptation, or that stomatal activity of indica plants differs from that of sativa plants. But we are talking about classification here—the identification of indica and sativa. I'm specifically talking about the role of terpenes in bud rot resistance, and differences in terpene profiles of indica vs. sativa.
My plants are protected from the rain because they're in greenhouses. We have high humidity here. Again, I've grown both indicas and sativas. I've had sativas get bud rot. I've grown 50/50 plants that get zero bud rot. And I've grown indicas that get bud rot, and indicas that are fairly resistant to bud rot. The reason for the differences are the terpenes produced and the amount of resin production.
In my grow the leaves are not saturated with water. Bud rot has no problem getting started, likewise for leaf molds (PM, septoria, and downy mildew). I've had plants next to other plants, and one will have lots of PM while the others don't. The organisms are sensitive to the presence of different types of terpenes.
The same order; rose
