By Brian D. Sparks, Senior Editor, Greenhouse Grower bdsparks@meistermedia.com
In the controlled-environment agriculture industry, greenhouse vegetables and cannabis are among the fastest-growing market segments. With that rapid growth comes the need for more knowledge about integrated pest management, and it’s perhaps even more critical in these crops because of consumer demand for a product that is both pest-free and pesticide-free.
Here’s a closer look at some of the latest developments in the research and adoption of biological products in these markets.
It is very exciting to see a new biocontrol agent make its way into the real world. Over the last year, the transfer of the predatory mite, Anystis baccarum, to Vineland Research and Innovation Centre’s commercial partner, Applied Bio-nomics Ltd., was a milestone that capped off more than 10 years of research.
Anystis mites are commonly called whirligig mites, because of their characteristic random zig-zag searching behavior. Naturally occurring populations of this mite are considered important natural enemies of pests in crops worldwide. But despite their good performance in the field, Anystis was never commercialized as a biocontrol agent, because no one could figure out how to economically mass rear this predator due to its cannibalistic behavior.
Anystis on Foxglove Aphid; Photo Taro Saito
Anystis attacks many common greenhouse pests such as thrips, spider mites, whiteflies, and aphids. It not only feeds on the vulnerable immature stages, but also manages to catch more mobile adults.
Early commercial trials in cut gerbera and sweet pepper showed that Anystis is able to establish and persist in the crop. Now that Anystis is available in Canada, more growers are trialing this new product, and researchers led by Rose Buitenhuis, Research Scientist, Biological Control at the Vineland Research and Innovation Centre, hope to have more data on how it performs under commercial conditions soon.
Learn more about this work with Anystis at GreenhouseGrower.com.
Renato Zardo, Director of Growing at Burton, OH-based lettuce and herb producer Great Lakes Growers, says greenhouse vegetable growers don’t have a choice when it comes to using biocontrols.
“We’re harvesting lettuce or tomatoes every day, so we can’t afford the pre-harvest or re-entry interval that comes with the use of traditional chemistries,” Zardo says. “They just don’t fit into our operation.”
Zardo notes that scouting plays an essential role in a biological-based program, especially for problematic pests like shore flies.
“You need to know what you’re controlling, otherwise you’re wasting your time and risk having to go back into the greenhouse, which is costly in both time and money,” Zardo says.
The experience levels that growers may have on the use of biologicals can vary greatly, especially for a crop such as cannabis.
“We have some cannabis growers that call us knowing exactly what they want, and others honestly have no idea how predatory mites work,” says Gregory Bryant, an IPM specialist with Beneficial Insectary. “When they’re looking for information, they might go a credible university website, or they might just search the internet for advice, whether it’s right or wrong.”
Bryant says hemp russet mite and root aphids are two primary pests for greenhouse cannabis, but because available solutions vary between states, more options need to be developed.
Building your knowledge, Bryant notes, starts with finding a good technical rep who knows what they’re doing.
“People that start out trying to use biocontrols on their own will often fail, and that’s because you can’t just rely on the information you find online,” Bryant says. “You have to know what’s going to work for your specific growing situation, which means you have to find somebody who knows what they're talking about.”
The good news for growers of crops such as hydroponic lettuce, Bryant says, is that the public stance on pesticides can only help the market.
“We are already moving in that direction, which puts us in a good place,” Bryant says.
Like Zardo, Bryant says scouting must go hand in hand with using the right materials in a biocontrols program.
“Scouting is always important, but even more so for biocontrols, because you need to be scouting not only for the pest you’re controlling, but for the beneficial you’ve applied, to make sure it’s working,” Bryant says.
Producing a good cannabis crop often starts with a solid IPM program. While cultivar selection, sanitation, and the greenhouse environment all play a role, you also need to know that the crop protection products you’re using are both safe and effective.
The problem, according to Suzanne Wainwright-Evans, Owner of Buglady Consulting, is that there are still cannabis growers using products not labeled for use on cannabis. They may see something is registered for use in another state or on another crop and think it will work the same way for them.
“You need to make sure the microbe you’re using is approved in your state, with a registration number from EPA,” Wainwright-Evans said. “Make sure what the manufacturer claims is in the product is actually in there.”
