Features Biocontrols Inputs
Inside View: Floriculture is blooming with new biocontrols

May 2017 – It’s long been recognized that greenhouse vegetable growers have been using biological control options more than their floriculture counterparts.

This is not to imply that floriculture producers are in anyway less keen or not interested in such things. But there are a number of very valid reasons why this may be so, such as:

• We eat vegetables, so there’s perhaps slightly more incentive to find alternatives to chemical pesticides.
• The original development of P. persimilis due to lack of effective acaricides being used by tomato growers subsequently led to the advanced use of bios, in particular in vegetable production.₁
• Many greenhouse vegetables are grown in media isolated from the soil, and growers have the opportunity for a good greenhouse cleanup to start a new season pest-free.
• Many flower crops are produced all-year-round and making biocontrols work in the winter months is technically challenging (short days causing many insects to head into over-wintering diapause).
• Equally challenging is the task of establishing viable populations of beneficial agents on short-term ornamental crops. Greenhouse vegetables are often in for a 10-month growing schedule, enabling healthy populations of beneficial predators and parasites to get well established.
• This also sometimes means customers find beneficials on their just-purchased potted plants or cut flowers. Since the buying public rarely know the difference between a good bug and bad one, they’re all likely to all be perceived as bad.
• It has sometimes been a challenge getting grower buy-in to the idea that introducing biologicals prophylactically, before the presence of a target pest, is a good idea, since many may view it is a waste of money.

Biocontrol companies have been working hard for years at developing systems for ornamentals, and now have protocols for many crops such as gerbera and poinsettia (some also having systems for bio pest management in medicinal marijuana). But with a hugely diverse range of ornamental plant species, there’s always work to be done.

But it’s not just insects that are used for biocontrol. Beneficial bacteria and fungi have been used for disease prevention and management for some time. Building microbial populations in soil and soil-less media should help develop plant community resilience. Check out the work of Metagenom Bio Inc. that (with help from “Bioenterprise”) is “working to use improved microbe communities to both enhance plant growth and reduce the impact of disease.”₂ Indeed, that’s a basic pillar of organic production systems.

During a recent visit to the Pacific North West by a group of U.K. bedding and potted plant growers and researchers, they mentioned that the “main development in IPM techniques in ornamentals is in the use of biopesticides, botanicals and semio-chemicals. Although not totally new, there has been a relatively rapid increase recently in the number [of these products] available and the growers who use them. There is still a long way to go to optimize their efficacy but we are losing conventional chemistry on a regular basis without new products coming along.”₁

Also, there are developments with growers producing some of their own bios in the greenhouse. Of course, there are many potential challenges with this, (e.g. quality control, lack of grower expertise, venturing too far from core business, etc.). Growers have long been encouraged to use ‘easy’ techniques of banker plants to maintain healthy beneficial populations. And there are options for more adventurous growers to start their own populations of some predators. For example, [since 2010] the AHDB of the U.K. provide growers with a factsheet on breeding Dalotia coriaria (a.k.a. Atheta) ‘Rove Beetle.’₁

1. Cary Gates, Flowers Canada.
2. Wayne Brough, (personal communication), Research and KT Manager, AHDB Horticulture, U.K.
3. Matt McIntosh, AgInnovation Ontario, referenced in www.HortiDaily.com, February 2017.

Gary Jones is co-chair of horticulture at Kwantlen Polytechnic University, Langley, B.C. He serves on several industry committees and welcomes comments at Gary.Jones@kpu.ca.