My Prestige Red, which are in the same house and have been treated the same as my Freedom varieties, are very slow in coloring up this year. Temps are 64 to 68 at night and 80 to 90 during the day. I am getting concerned since its already mid-November. Could it be due to a heat delay?

Prestige is a later variety than Freedom, but you also could be seeing heat delay. I just moved my 6" Prestige to the front of the house where it is warmer and my Freedoms to the rear. What we do for our points!

Deanne, Once a week I put on my paisley shirt and wire rim sun glasses from the 1960's, strap on my guitar, and walk up and down the isles singing "Kum-by-ya" to my Poinsettias. Doesn't every grower do this for their crop???....Michael Pawelek
PS- I am still wondering about your comment last month about "cutting variability even in asexual propagation". Is there something going on in my greenhouses at night I'm not aware of?

I live in the Northeast. My Prestige were not subject to any abnormal temperatures. Actually the temps here were milder for August and September than the previous two years. I have 30K Prestige in 6 and 6.5 pots. I have them in poly-houses and I have them underglass. They are all 2-3 weeks later than prior years. Last year I thought i was given early prestige accidentally they were in full color Dec 1st this year it looks like they will be in full color for the 21st.

Tim -

Prestige is a mid season variety that we would expect to finish 10-14 days later than Freedom which is an early season variety.

GROWERINCT - what have your night time temps been averaging since flowering initiation?

We have been hearing from a lot of growers in the northern US that feel that Prestige is later than in previous years. Prestige is sensitive to heat delay so if night temps exceed 74F at the time of flower initiation it will delay. After flower initiation temperature is the driving force behind the rate of bract development. Warmer temps equal faster bract development. With rising energy costs many growers are reducing temperatures to reduce fuel costs. With a plant like Prestige when you factor in possible delay of initiation followed by cooler growing temperatures it could create a situation where Prestige is even later than some growers are used to. This may not be the case in all greenhouses but we are seeing a trend where growers are reducing temperatures and some varieties like Prestige do not respond well to the cold growing technique.

I run 65N and my cooling is set at 73. My houses run about 75 during sunny days in September and October. Our day and night temps are tracked with Qcom. I pulled a history and have not had a night temp above 70F for August, September, October, or November. Our night temps have been 65F since our cuttings arrived. Except for a couple nights in August temps were 70F. I don't know if its stock selection on eckes part or the possibility of shipping stress (our prestige cuttings arrived warm 85F in the boxes)But under the same growing conditions as last year our flowering is later.

Oh, Michael, if you only knew!
I just got through with 15 minutes of screaming alternately at the 6" Prestige to hurry up and the 8" Prestige to slow down! (And they are in the same house!) Let's face it, like nuclear fission, if it were easy, every Tom, Dick and Harry would be doing it at home!
Peace and Love! **

Watch where your sensor is located. Last year Argus was measuring just above the crop canopy. I ran into serious heat delay because my heat was delivered through the floor and I was several degrees warmer just under the canopy.

Michael, you are too kind singing kumbyah. I grab a six pack and walk down the isles singing "Take this job and shove it!" Have a good Thanksgiving folks, it's time to get busy. Marty

GROWERINCT - There are other factors that can contribute to flower delay such as use of B-9 or Florel past flower initiation or high rates of Bonzi too early. Light pollution can also create a delay situation. Not sure if anything applies here - these are just some other factors to consider.

Deke's point is also valid - it makes a big difference where your sensor is located as temperature at or below canopy height is critical as well as media temperatures.