Re: REB: fall cyclic vs other

 (Sending to group. Computer put Linda's adress into e-mail insteas of group
e-mail)














 He would have used a growth chamber. A controlled environment.



Artic Fox is control for Immortality. So he is only doing these two
cultivars.



He hasn't done any parameter studies yet. My own hypothesis is 6 day betwwween
16 and 21C as minimum temperature. Of course variations from cultivar to
cultivar.



I'm, assumming night temp was set at 19C and day at  some other temp. He did
say byut I can't remeber for sure, think it was about 26C



I would think you mean above 21 C dfor several months. My guess is that
noithing would happen. Plants would just sit there.



This has been done with bulbs, and they just sit there, until temperature
lowered. The temperature used for Dutch Iris bulbs is 35C, to keep them from
starting spring growth and flowering.



Chuck Chapman















-----Original Message-----

From: Linda Mann <lmann@lock-net.com>

To: iris@hort.net

Cc: Chuck Chapman <irischapman@aim.com>

Sent: Mon, Nov 9, 2009 12:39 pm

Subject: Re: REB: fall cyclic vs other












Chuck, do you know whether or not he is looking at other cultivars?




& how many hours were they were exposed to 19C and what the upper
temperature was?




I'm very curious to know what the range of temperatures for bud set is
(i.e., maximum as well as the minimum he reports of 19oC for ARCTIC
FOX), and how much/if it varies among different types of rebloomers.




Since he's in Minnesota and you are in Canada, the minimum is of greater
interest there, but here the minimum is easy to reach - night time
temperatures are normally in the mid 60s by the end of bloom season here
(mid May) and stay there, or warmer, until Sept.




What happens if they are exposed to 20C or above for several months?




 <Richard Harkness at University of Minneapolis has read my study and
is using the data t orun some of his own experiments. A few weeks back
he let me know that he got flower bud set om Arctic Fox with 6-9 days of
exposure to min night temperature of 19C [~66F]. So it looks as if
temperature, rather then time is indeed the biological trigger for
flower bud set. Chuck Chapman>




Linda Mann


east TN

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