Powdery Mildew Being a Pain? Effective Products for PM Relief.

PMRoses4

Powdery mildew on cut roses in Ontario.

With May’s weather continuing to be up and down, humidity control is a problem in the greenhouse, meaning Powdery Mildew (PM) is too.  This pest is rearing it’s ugly head in crops like Kalanchoe and Dahlia.

We won’t cover the basics of PM here:  biology, spread and prevention were covered in a previous post.  Instead, we’ll focus on monitoring, and which control products to use once you’ve found an infection.

This post was written with help from Plant Pathologist Ann Zemke of the Chase Research Group.

Continue reading “Powdery Mildew Being a Pain? Effective Products for PM Relief.”

Advertisements

Fainting “Freedom Red”? Wilting “Whitestar”? Potential causes of Poinsettia collapse, solutions, and the importance of testing.

DSC_1230

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.”

Managing Million Bells, 2017 Updates

Image result for calibrachoa plugs

Rooted Calibrachoa plugs. Photo from jparkers.co.uk

It’s that time of year again, when unrooted cuttings or rooted plug trays of Million Bells (Calibrachoa) are first arriving in the greenhouse.  

When they go right, Calibrachoa are a relatively easy, staple spring crop.  However, when million bells go bad, they go bad BIG time.

To help your crop turn out this year, Chevonne and I have compiled some info on how to prevent and deal with common issues in Callies.

Continue reading “Managing Million Bells, 2017 Updates”

Ramping up thrips biocontrol BEFORE they get out of control!

WFT on hibiscus_Caitlin McDonald_1

Western flower thrips adult on an open Mandevilla flower.  Photo credit: Caitlin MacDonald, USEL student.

Now that the warm weather is finally upon us, it’s time to start worrying about thrips control.

What we’ve learned over the years is that pesticides just don’t cut it – the only reliable chemical for western flower thrips in Ontario is DDVP, which requires constant application.  This means biological control is your best bet.  Here’s a summary of the most effective tools, tricks, and timing, to ensure your biocontrol dollars are well spent.

Continue reading “Ramping up thrips biocontrol BEFORE they get out of control!”

Can you safely mix nematodes and pesticides?

Entomopathogenic nematodes – used to control fungus gnats, shoreflies and thrips – are often a “gateway bio” into biocontrol use in greenhouses.  This is because not only are they effective and easy to use, but they’re generally compatible with insecticide use.   Readily applied with regular spray equipment or through drip lines, nematodes can even be tanked mixed with pesticides to save on labour costs.

In this post, I’ll share some of my research at NC State, looking at which commonly used pesticides in Canadian and U.S. greenhouses are safe to use with nematodes.

Continue reading “Can you safely mix nematodes and pesticides?”

Update on Met52 Availability – EC but no Granular from Plant Products

142237-250

Met52 EC is available from Plant Products.

In anticipation of Monstanto BioAg’s decision regarding re-sourcing Met52, Canadian distributor Plant Products stocked their shelves.

Plant Products currently holds over 1000 units of the popular Met 52 EC (emulsifiable concentrate) product.  This should be enough to bridge any gap in supply from Monstanto. Met 52 EC has a shelf life of up to 1 year if stored properly.

Met 52 EC is registered for use on strawberries, lettuce, cucumber, zucchini and fruiting vegetables (pepper, tomato, eggplant) in  Canadian greenhouses.

gmet52

Granular Met52 is not currently available in Canada.

Unfortunately,  floriculture growers are still without a Metarhizium-based  insecticide for now. Plant Products confirms that Met 52 Granular Insecticide – the only formulation registered on ornamentals – will NOT be available in 2016.  We will update you on any potential availability in the future.

Meanwhile, stakeholders are working with the registrant to explore the possibility that Met52 EC could be registered for greenhouse ornamental use via the minor use program. However, as this previous blog post explains, even label expansions for currently registered products take time. However, biopesticides like Met52 are often expedited.