« Pinch vs. Unpinched Update: Garden Mums | Home | Biological Control of Greenhouse Pests »
Poinsettia Propagation: Updates and Pictures
By admin | July 23, 2007
We have started to grow on our first batch of poinsettia, the 10 inch pots, and we are in the process of setting up the plant for pinching in about a week to 10 days. Below is a good picture of what we are working with now and I am pleased overall. I must continue to do 
all the things I stated in one of my previous posts titled Poinsettia Propagation: We’re off Mist. It is important now for us to keep the cuttings as even as possible and stack the nodes prior to pinching. This means more Cycocel sprays and increasing light levels.
Our other batches of poinsettias are in various stages of rooting and growing on. Our 6.5 inch are nearly 3 weeks old but they were at 15 days when I took the picture below.
Obviously these plants are off mist and we are in the building phase but I have to comment about the cuttings and where they came from. These were our first cuttings from Ethiopia and they were very different from any that I’ve seen before. This variety is Eurglory Red from the German Breeder, Dummen. Our cuttings from Dummen this year have easily been the best in propagation. They rooted faster than our cuttings from Ecke or Fischer. These cuttings from Ethiopia were different however, from the Dummen cuttings from Costa Rica. The Costa Rican cuttings were softer and even though they rooted a day sooner than the Ethiopian cuttings, they didn’t hold up as well under the mist for two weeks. I have never seen poinsettia cuttings with stems as hard and leaves as tough and thick as these from Ethiopia and they still rooted quickly and uniformly. I’m sure it’s the difference in growing conditions between the two countries. I know it’s very humid in Costa Rica and I’m sure this plays a role in nutrient uptake and overall stock plant management. The climate in Ethiopia is brighter and drier which allows them to keep the stock plants full of nutrients (due to consistent transpiration rates) and makes the cuttings harder due to the great light levels. I love Costa Rica but Africa wins this battle.
We still have a bunch of 6 inch poinsettias under mist and in two weeks we will stick our 4 inch.
We are getting a nice callus on these cuttings and we are starting to ween them off the mist and increase the light levels. The second picture is a close up of the callused cutting on day 7 in propagation. These cuttings will throw roots in 2-3 days and I will get some pictures from the same cuttings to show the development of the roots.
When our 4 inch poinsettia cutting arrive in two weeks, I will attempt to follow and document the development of a few of the plants with day to day pictures. If you want to read all of my posts about our Poinsettia Propagation click here.
Topics: Poinsettias, Day to day |
July 26th, 2007 at 9:24 pm
I notice you are talking about Cycocel early on and I see some Premium Red from Dummen in the pictures… I would not recommend Cycocel on the Premium Series. It is important to get early growth on this cultivar. Trial after trial has shown it will not stretch or bolt. Of course other cultivars are different. Nice website!
July 27th, 2007 at 8:34 am
Paul,
Thanks for the comments. I am only spraying cycocel on the Euroglory and the Infinity Red nothing on the Premiums. Does Dummen have a special graph for tracking the height of the Premium Series? I thought I saw one at your booth at OFA.
July 27th, 2007 at 5:41 pm
Yes. There is a graph which Dr. Hammer has provided. He collected the data over the past years growing premium at the Purdue Trial. You can get a copy faxed or emailed to you by your broker rep, Dummen product rep., or from Dummen USA at sales@dummenusa.com or 614-850-9551. It is not on the website, but I will request that it gets posted by next week.
July 30th, 2007 at 4:47 pm
Any advise on controlling fungus gnats 2 weeks after sticking. I have rooting on most but detected larva on several.
Sam
July 30th, 2007 at 7:25 pm
Sam,
Fungus gnats are a real pain, especially on Poinsettias. Do you have good roots out of the callus? If your cuttings are already off mist, and they probably should be, then you can really start to dry them down. This would be the number one thing you can do to control the fungus gnat larvae. But since this is a cultural control and since it can take a few weeks to see results, you probably want a chemical control. My preferred chemical would be Citation. It is an insect growth regulator that works will on fungus gnat larvae. Other good controls are Ornazin and Gnatrol. If you need rates read the label or send me an email. They are applied as a drench and you should target the are in the soil where the fungus gnats reside( the top third or half of the soil). I would trial some plants first before doing a broad application. I’ve never seen phytotoxicity from any of these chemicals but you must be sure. Gnatrol is the safest and its effective as well. Good luck and keep us posted on your success.
July 31st, 2007 at 11:26 pm
Consider trying nematodes (Steinernema feltiae) from Koppert Biologicals (www.koppertonline.com). I have tried them on other crops (we don’t grow poinsettias) and they work - trials have shown that multiple applications gives control equal to Safari (Greenhouse Grower a few months back). Also, there is no REI or reporting since it isn’t a pesticide (no EPA number). Obviously, they are especially useful for edible crops such as herbs for which many materials aren’t labeled.
Doug
August 1st, 2007 at 8:50 am
Great comment Doug. I have used Atheta beetles from Biobest in the past and they can be very effective. I have tried the nematodes with some success as well. Biological control is always worth a try. Some pest problems are not ideal for control with beneficials but it’s a viable method and much easier on the plants and your workers.
August 1st, 2007 at 9:02 am
Is there any literature on a ‘tolerance’ level for fungus gnats? We use 4′ x 5′ yellow trap cards to monitor, along with running crop drier to keep gnats down, but at what point on your card count should you be concerned? I do a rolling weekly count, so I do know how the population is progressing.
Has anyone tried a 1/2″ layer of sand on the soil surface, and if so has it been effective (I realize this is only feasible for a smaller production volumes)
August 1st, 2007 at 12:00 pm
Anna,
I haven’t found any good info on threshold levels for fungus gnats. I have talked with several entomology professors and this is something they are working on but thresholds for thrips and whiteflies seem to be higher on the priority list. We also monitor our pest populations on a weekly basis and graphically track them on Excel. If our population of fungus gnat adults stay below 20 adults caught per week, I don’t get too concerned. I lower that threshold to 10/week in our prop houses.
I don’t know of anyone trying the sand method. Sounds interesting, but as you said it’s impractical for a larger producer.
Thanks for the comments Anna.
August 1st, 2007 at 2:53 pm
Anna,
A topdress of rice hulls (PBH) could be used as well (obviously this takes labor). We did use them on hollyhocks to prevent splashing of the water from the soil to the foliage (hollyhock rust) and it was fairly successful. They dry out very quickly and probably would deter the fungus gnats. The only issue is that they fall out of pots very easily.
Doug