Yellowing is not neccessarily a lack of N.

[guest2012y]

CC...The One has exhibited this exact same thing for me...I had one lockout once,turned it around in a jiffy and she was green all the way to the end. By far the best type I have at the moment.
Mr.G.... Having grown several varieties myself over the years I notice this exact same thing. You're on top of the game when it comes to breeding for the traits that are desirable.
V...I've got some Mr. G. White Wizard crosses I'm itching to dig into myself.

 

[Clackamas Coot]

I think it's probable that you're more of a connoisseur than us southlanders Coot, but I'm pretty sure you'd give the thumbs up to a bowl of J7 if you were here now. Maybe not. Maybe you'd say, "Man, why din't you guys flush this first?"

Mr. Greengenes

Everything that I grow and have bred are from my 'yutes' in Southern California. I cut my teeth on growing in the Fallbrook area as well as Laguna Canyon - circa 1978. Given the weather patterns and the general distrust of 'outsiders' we grew landrace sativas almost exclusively.

Then again that was before the boys up north showed us how the boar runs through the buckwheat by golly! The whole 'Northern Cali' paradigm.

Then there were the boys at 'Sacred Seeds' in Oregon and Washington and the British Columbia Grower's Association (BCGA) in Vancouver, Washington - all of which showed us that growing indica-dominant hybrids was the ONLY way to go.

Touching isn't it? LOL

CC

 

[MrFista]

Outstanding MM thank you very much!

CC - I have a database only search engine, the problem being I have access to almost EVERYTHING. Do you know how much everything actually entails... I could spend all day just reading the names of the journals alone most of which have publications in their hundreds and many publications number thousands of pages... So my search dilemna is about narrowing the search down.

Arginine. What has the waste product arginine. This might help us identify mycorrhizal helper species, that further symbiosis only ever hinted at here (by MM who leads the way). Have any lacto bacillus users used LB on soil only and noticed a greening response in the plants? I got some reading to do first then I might have more to say on fungi and N.

Now - those strains that don't senesce. I don't think this is genetic inferiority, you might actually have a mutation there that is highly advantageous to growers. Even if that particular strain is not so great, it might be possible to cross those genes out to help some of the real finicky strains to finish strong. In effect, it could generate a breeding programme going in the opposite direction of auto flower breeders.

The value of such strains is potentially enormous for those in subtropical to tropical climates. Delaying senescence in many commercial crops is what has made them viable (especially flowers). The non senescing genetics you have there will also be highly desirable for research purposes.

Please look after those genes.

Annuals that do not die go through a stage of development between warm seasons where they get very beat up and sickly. A lot of this is to do with senescence. Depleted stems and flowers fold and rot and diseases get into the plant via many entryways from the dying plant parts. This is meant to finish the plant off surely, but in some cases the plant fights back, all winter it fights for it's life against wet cold conditions and multiple wouding sites. By spring, after a dry spell, the wounds finally dry over with calluses and the plant begins to resume vegetative growth with some semblance of health.

Imagine if the plant didn't senesce. The flowers get snipped off on a non rainy day, you could seal the wounds even. Then the plant gets to overwinter without anywhere near the problems of a typically senescing plant. The second year would see far more rapid development of the vegetative cycle on an already established (and hopefully large) plant. you could grow freaking trees with those genes in the right climate.

To test this. Get the non senescing (NS) strain and do a side by side reveg with another strain that senesces. The NS strain should have more leaves and thus more roots as it reverts, which should eventuate in a faster recovery and subsequent better yield per time frame.

 

[guest2012y]

"Please look after those genes."

I recognized the importance of this as well after the first flowering....more so after the next couple runs. I've crossed The One with BMR,and as you know Fista (and CC)I have other plans in the future utilizing these genetics. However,it's pretty important to keep the original intact and I plan on looking after it until my death.

 

[MrFista]

I could get a doctorate isolating the gene responsible for leaf senescence. Might be asking you for a delivery one day.

 

[VerdantGreen]

its likely to be more than one gene though.

 

[MrFista]

LOL.

Knew I shoulda rephrased at the time but a visitor arrived.

Gene/s responsible for senescence. In particular, leaf senescence.

If it is just something missing it will be (relatively) easy to find the missing region by matching it against another plants genome that undergoes typical senescence. If it is merely repressed, it could get very complicated.

 

[MrFista]

Still much to learn but I believe we can gain much insight from those with the non senescing genes. Crossed with a senescing strain the seeds will provide plants to learn plenty about the gene expression from. I'm still a learner but some things I realised we could look for in the plants grown from such a cross are:

All the plants from the cross do not senesce - A dominant allele is involved.

All the plants from the cross senesce - A recessive allele is involved.

There is a range of senescence in the plants - Two or more alleles share co-dominance.

Males only senesce - it is a gene located on the Y chromosome.

Dioecious species (two seperate sexes) like cannabis have sex chromosomes, however some have developed monoecious characteristics (hermaphrodism). This seems to be a backup pathway to producing seed in dioecious species suggesting it evolved in cannabis before the seperating of the sexes.

If true hermaphrodite strains are still truly monoecious remains to be clarified for me unless someone here already found this information? My experience of female only seeds from such a strain indicates that if they aren't monoecious, they're still different to what most call cannabis these days. The problem with looking at cannabis evolution is that there has been so much artificial selection over a relatively short time frame accelerating their evolution in several seperate directions.

Monoecious strains do not contain sex chromosomes and so calling their offspring "female" might be wrong. LOL.

 

[Microbeman]

Wait till the bacteria/archaea helpers which regulate nutrient uptake at the apoplast at the mucigel interface are identified/discovered. Everyone will be ooooing and aawwwing (some terms used loosely).

 

[MrFista]

I wondered about apoplastic sentries. Thanks for clarifying that (and adding mystery to it as well).

I messed up earlier saying a search for arginine metabolites would uncover MHB's. For all I know the fungi convert other nitrogenous substances to arginine and the MHB's produce something else. Actinobacteria spring to mind as producers of said nitrogenous material.

 

[Yankee Grower]

all of which showed us that growing indica-dominant hybrids was the ONLY way to go.

Is that sarcastic or serious?

 

[Clackamas Coot]

Sarcasm

 

[!!!]

Many strains' leaves will yellow and fall off naturally during mid to late flower. My skunk #1 was shedding leaves 3 weeks into flower. It practically defoliated itself.

 

[hash head]

does anyone notice that some leaves can brown and become crispy and fall off in a very short period of time? like 12-24 hours from nearly normal to complete off the plant?


would a plant that stays completely green apart from the few leaves that fall off it count as one that does not senesce?

 

[VerdantGreen]

same cut (sharksbreath) same soil mix, same flowering time (just over 10 weeks in and ready to chop)
differences between the two are the lower one was under a stronger light (therefore using more nutrients) and in a slightly smaller pot. nutrient availability does most certainly make a difference to how they finish.

VG

 

[guest2012y]

Would you say the yield was the same...or just a bit less...or more?

 

[VerdantGreen]

dont know yet, but i would expect the lower one that was under more watts to yield a fair bit more. i'll let you know. both flowered under LED's.

VG

 

[VerdantGreen]

or did you mean gram per watt yield? in that case probably the greener one because the yellow one was in a cab too small for the light really so not as efficient.

---

it would be interesting to hear how everyone defines 'too early' and what they see as ideal. for a strain that fades fairly normally

 

[MrFista]

Nice one Verdant. Further proof big is better when it comes to pots.

I would only be able to call the senescence too early after growing the same cuts in the same system several times and knowing what is typical. Otherwise I'd be guessing, as we know sometimes one variable can change a lot. Seedlings will have the bell curve mentioned earlier, a few early, a lot in the middle, a few late. The early ones will make good keepers for developing AF strains and to gift to friends in colder climates. The late for tropic sub tropic outdoors for increased yield (without the frost risk). Indoors? A lot of people are happy with the 8ish week finishers, if I encouraged a longer finish, the added weight would need to be worth it.

Senescence is normal (in most strains), but the degree is obviously influenced by environmental factors as we see in Verdant's photos. The range of variation should directly correlate to the range of environmental factors, but they may be many and rather a confusion to untangle with multiple influences.

The question now is - will the yield suffer from increased levels of senescence?

I think it will. Commercial crops delay senescence for increased production. In some cases they've done this just as I am outlining here, by finding the 'mutants', the plants that don't senesce, and running breeding programmes with them. Early onset senescence with a strain you know well is never a good sign...

As we know there is a variation over strains so examining senescence needs to be done working within the confines of single strains or cuts of strains. Cuts are great for examining environmental parameters, seedlings are great for directional selection.

I suspect lack of a certain micronutrient or more, when unavailable from the soil, induces leaf scavenging (early onset senescence) for that nutrient. N doesn't stack up when you look at symbiotic legumes with loads of free N still undergoing senescence. We have to always recall we are talking annuals here, and senescence is part of the plants programmed 'suicide' -> regeneration via seed. Although there is (hopefully) no seed, MJ doesn't seem to have figured this out yet and keeps pumping nutrients to the flowers, including crucial for seed development nutrients, from the leaves. As we are not developing seeds in the majority of our crops this senescence is not needed to produce outstanding flowers. And from the smoke reports of the non senescing strains, this is indeed the case. I wonder what the seed viability is though?

What environmental factors affect onset of senescence? Photoperiod (onset), phyllotaxy (more shade, more chance of leaf being scavenged), plant density (ethylene dispersal), temperature (cold shock?), nutrients (gotta come from somewhere right), mycorrhizal symbiosis or lack of (that arginine delivery), water (just try to deny em water), microherd (nutrients processed here, making more available, lack of healthy microherd = less organic nutes = earlier onset senescence = decreased yield).

Once we know what typical senescence is for a strain we will then be able to evaluate strains against each other. Much of this information will already be out there.

I think normal senescence in plants that lack for nothing in their environment will add a little something to the flowers regardless. The question is what is normal. Again, growing and knowing a strain is the only way to get a handle on that.

I guess there's two types of senescence. Symptomatic, and natural.

 

[guest2012y]

or did you mean gram per watt yield? in that case probably the greener one because the yellow one was in a cab too small for the light really so not as efficient.

---

it would be interesting to hear how everyone defines 'too early' and what they see as ideal. for a strain that fades fairly normally

Just the overall yield was what I was curious about..I've never done the gram per watt thing...closest I get is if I'm not getting at least a pound per 1000 watter..........somethings wrong with me!