I have Alternaria on my Maren Poinsettias. Also had this on last years crop and you told me to use Phyton 27. I have two different rates and don't know which to use. On the Ecke Poinsettias Disease Control chart it says use 15oz/100 gal spray and the label says use 2 oz/10 gal water Scab rate. It does not give a rate for Alternaria only Botrytis, Scab, Powdery Mildew, Erwinia,and Xanthomonas. Thought I would use the Scab rate but wanted to check with the experts. It has been 8 days since my cycocel/B9. So I'm safe there. My next question is on my Gnatrol drench. I know not to mix with fertilizer or fungicide containing copper. Is there a waitng period for applying the gnatrol after using the Phyton spray (copper)? Thanks in advance for your help. Lee

Lee, Alternaria is a disease of warm wet conditions (read deep south). It is often not even mentioned in lists of poinsettia diseases. Here are 2 sources of info: http://www.doacs.state.fl.us/pi/enpp/pathology/pathcirc/pp277.pdf and http://www.apsnet.org/online/feature/xmasflower/
It is a common disease here in Florida and can complete wipe out a crop if not controlled. Depending on what your production environment is, anything you can do to keep water off the foliage will have a very significant benefit. In an enclosed greenhouse and on drip irrigation I never have it. But if I go to any overhead watering I will get it on medium-green leaf varieties like Maren and Peterstar. If you cannot keep the foliage dry, then next year plan on having the disease problem and do preventative sprays. There are several fungicides that work. In addition to Phyton, Heritage and Medallion have performed well in trials. Jim

K and L Nursery -

To avoid any problems with the Gnatrol after using the Phyton 27 you should wait 7-10 days before making the Gnatrol application. You may consider using the Hertige or Medallion for control of the Alternaria as they are not copper based products and there shouldn't be a problem when these chemicals are applied in close proximity to a Gnatrol application.

Thanks for the info. I'll use Medallion as a spray treatment instead of Phyton. I have drenched both Banrot and Medallion already on this crop. I have just finished spacing and will be using drip tubes now to help reduce wetting the foliage. This is a beautiful crop I'd hate to lose any! Thanks again Lee