Re: HYB: germination - chill time

A few added facts. First re number of days of soaking/rincing -- A study was published in AIS bulletin a few years ago. It measured amounts of inhibitors in water each day after soaking and rinsing. By fifth day it was almost nil. In my own experience, the water from the first few days of soaking is quite brown. After fifth day and later, ther is seemingly no colour added from soaking.. So... soaking after five days proably does't do much.
Seedlings germinating in fridge, like with myself after three months, have most likely been able to germinate at least two weks before then, but have been operating at a very slow biology condition at low temps of fridge, ie: about 40F, 4C.
When one seed in a batch is germinating in fridge, the rest in the batch are most proably alrready to germinate.
Paul is very correct. While seeds that are round and not dried at all seem to have less inhibitor, even with some drying, there is an increase in inhibitor. Thus if seed pod is starting to split, the inhibitors are already ther. To avoid development of inhibiors, get seeds out of pod and planted while still round and before pod starts to turn brown. That is slightly immature. I have seen experiments don on this. Ther was some germination of seeds. Some pods even seemed to be at a good percentage rate. But in general rates of number of pods showing germination and percentage of germination, was not up t owhat I wanted. Personally I suspect pods from Califorinia breeding plants would be the ones producing best germination in these conditions. The person doing the experiments I observed was someone in a much warmer climate then mine, but still in an area where they needed to breed fotr hardy plants. Lets be honest here. California plants have over fifty years of selection for germination in California climates, and California plants are amoung the first to die in my climate.
Long term storage of several months does seem to increase seed germination in some plants and reduce chilling times. 

Linda

1-- Answered above
2-- Seeds are ready to germinate after 2 to 2.5 months in fridge. Take them out and give them a chance. Plant in soil and keep at room temperature.
3-- Second flush of seeds would seem to be from an exposure to fresh air, thus more of whatever seed needs, proably oxygen, but perhaps carbon dioxide. Burittos are in danger of suffocating seeds The second flush takes 2-4 weeks as they operate very slowly at 40F, in fridge. It would just be a few days at room temperature. The ones that turn to much after planting are proably seeds that suffocated in burito, but were preserved from rotting by fridge temperature.
So .......I still suggest, soak and rinse seeds for five plus days (after shelling) then into damp peat moss (preferably) or buritos,but rinse and expose to air at least once a week.
Remove from fridge at 2.5 months (10 weeks ) and plant at room temperatures.
With this you should get a very high germination rate, and plants will be plenty big enough to go into garden when danger of frost is past. They should bloom the following spring. 

Chuck Chapman



- -----Original Message-----
From: Linda Mann <lmann@lock-net.com>
To: iris@hort.net
Sent: Mon, Jun 29, 2009 10:12 am
Subject: [iris] Re: HYB: germination - chill time
1--"Air drying at room temperature results in <less> chilling requirement to? 
remove germination inhibitors? I'd read somewhere that drying results?
in <increased> production of water soluble germination inhibitors (which? 
are really easy to get rid of), but hadn't heard that drying <reduced>?
time required for chilling. Or missed it somehow. It seems to?
contradict the experiences others have reported of getting immediate?
germination of undried seeds without <any> chilling. But like you say,?
that may be a totally different gene pool from the TBs we can grow in?
our climate.?"
2_"My impression is that I'm getting faster turnaround without drying seeds? 
first. Most crosses germinate first flush after about three months in?
the fridge, some after only two months, with no noticeable difference?
between those dried, soaked, then burrito'd vs those straight into the?
fridge fresh, shelled & burrito'd or not.?
?
Except that those that are dried, shelled, soaked obviously get into the? 
fridge several weeks <later> than those that go into the fridge fresh.?
Late June/early July vs early late July/early Aug. For me, those few?
weeks can make a <big> difference in whether or not they are big enough?
to line out before hectic, allergic spring bloom season starts.?"
3-- "Second flush might or might not be big enough that early, and 3rd flush,? 
coincident with "normal" outdoor germination is not big enough by then,?
so usually stay in pots here till early fall & take another year to?
bloom size.?
?
Chuck, any thoughts about what's going on with those seeds in those 2 to? 
4 weeks between flushes of germination? Anner has suggested, I think,?
based on Demo, that the amount of time they are spending at room?
temperature as we rummage thru the burritos looking for germinating?
seeds is enough to trigger the next wave of germinants, with or without?
more chilling. Subsequent sprouting takes a few weeks.?"


Date: Mon, 29 Jun 2009 16:35:29 -0400 (GMT-04:00)
From: Paul Archer <pharcher@mindspring.com>
Subject: Re: [iris] Re: HYB: germination - chill time
I'm sure Chuck will respond about the same way but I believe the "air drying" Chuck is referrring to (quote below) is extended drying and holding at room temperature, not the intial drying before placing in stratification. That is documented in some species to occur, referring to Deno's publication. Air drying is not the same thing necessarily as holding at room temperature.
Also,if we were to follow the "Happens in Nature Approach" mentioned earlier... in Nature there is the inital drying down that induces a response to produce germination inhibitors (i.e. Summer) which would then be followed by a a Fall with no chilling days and then Winter and then the process starts. If it were a wet Summer or climate/microclimate that would allow the seed to not dry down maybe get some growth in before freezing (i.e. more southern regions). 

Paul Archer
Indianapolis, IN  Zone 5

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@hort.net with the
message text UNSUBSCRIBE IRIS
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index