Now that poinsettias are safely tucked into their prop trays and the threat of Erwinia (Pectobacterium) is almost over, it’s time to think about other Poinsettia issues.
Root rots, nutritional issues, environmental stress and PGR mistakes can all be costly in this high-value crop. Read on for common pitfalls and how to avoid them.
Continue reading “Poinsettia Prep Refresher”
Bemisia whitefly (Bemisia tabaca) adults on poinsettia. In high pressure years, poinsettia plants can quickly become unsellable due to this pest.
The floriculture industry in Ontario seems to have mostly avoided heavy aphid AND thrips pressure this spring/summer. But from everything I’ve been hearing, we are NOT going to be that lucky with whitefly on poinsettia this year.
This post goes over preventative measures that should be taken as soon as cuttings come in the door, biocontrol programs for whitefly on poinsettia, and WHEN and WHAT to spray for this so you can avoid resistance issues.
Continue reading “Worried About Whitefly? Control Strategies in Poinsettia for 2018.”
Wilting of a poinsettia plant on a bench of otherwise healthy plants could be Pythium root rot. But then again, it might not…
From now until mid-November is when you’ll most likely see plant losses in poinsettia due to severe wilting. These losses can be considerable: anywhere from 2-15% in Niagara operations in past years, with disease pressure seeming especially high this year.
Pythium may be considered the most “likely” culprit in Poinsettia in this area, but this isn’t always the case, and misdiagnosis can mean wasted fungicide applications. Read on for a list of likely suspects and appropriate control measures.
Continue reading “Fainting “Freedom Red”? Wilting “Whitestar”? Potential causes of Poinsettia collapse, solutions, and the importance of testing.”
2016 turned out to be a bad year for Lewis mite (Eotetranychus lewisi) in poinsettia. Although it’s too early to say how 2017 is going to go, you should be considering possible preventative measures THIS WEEK for Lewis mite, especially if you have a history of Lewis mite with your cuttings. Treatment of this pest is more difficult later in the crop (though not impossible). Keep reading for biological and chemical control options for this pest.
Lewis mite, a species of spider mite, can cause major crop losses if left uncontrolled.
Continue reading “Thinking ahead: What you can do THIS WEEK to prevent Lewis mite damage in your poinsettias.”
Juvenile and adult Bemisia whitefly (Bemisia tabaci). There are 2 biotypes of this pest (“B” and “Q”) which look identical; however, their response to chemicals is very different.
Poinsettias cuttings are here! Unfortunately, they will likely arrive with unwanted “presents” in tow. This includes Bemisia whitefly, a pest that can be hard to control with natural enemies and can ALSO be resistant to pesticides. So what’s a grower to do?
By implementing some preventative measures RIGHT NOW, and understanding WHEN it’s appropriate to spray, you can help save yourself a lot of headaches later.
Continue reading “Christmas in July: tips for controlling whitefly in poinsettia. (Hint – start now!).”
Lewis mite. Photo from University of California.
You know how I just wrote a post on how you need to look out for unprecedented mealybug infestations in your crop this year? Well I lied! Now you need to look out for mealybug AND unusually high numbers of Lewis mites!
Read further for what consultants have been seeing out in the greenhouse and for effective control strategies.
Continue reading “Lots and Lots of Lewis mites! (And how to go about controlling them in poinsettia).”
Citrus mealybug feeding on a flower stem.
Last year several consultants and I noticed something strange. A number of greenhouses in Ontario had noticeable infestations of mealybug in their poinsettia crop. This was the first time many in their 25+ year careers had seen this (e.g. see Mel Sawaya’s article in Greenhouse Canada Magazine).
It’s unclear yet if phenomenon will repeat itself this year (or perhaps affect even more operations), but growers should be on the lookout for this pest. Keep reading for more information about the potential cause of these mealybug infestations, and possible solutions.
Continue reading “Mealybugs…on poinsettia??”