What About Biopesticides?

Biopesticides are made from naturally occurring plant extracts, bacteria, and fungi that control populations of insects, mites, and fungi. Depending on what pest they control, the product may be referred to as a bioinsecticide, biomiticide, or biofungicide.  Products that control mites may be listed as a bioinsecticide even though mites are not insects.  Another way companies list them is biological insecticide or biological fungicide.  Sometimes, these products are referred to simply as “biologicals.” Some common examples of biological insecticides include Dipel (Bacillus thuringiensis subsp.), Neemix 4.5 (azadirachtin), and Pyganic EC 5.0 (pyrethrin). Examples of biological fungicides include Serenade (Bacillus subtilis), Howler (Pseudomonas spp.), and Rootshield WP (Trichoderma spp.).  Many are OMRI-listed with approval for use in organic production, but not all.

Benefits and Drawbacks

Biopesticides are a great addition to your pesticide cabinet. If you are an organic grower, you’ve likely been using biological products from the beginning. Still, many conventional growers are becoming aware of their usefulness and take advantage of the success of biologicals as well.  Generally, biopesticides are considered safer and have low pre-harvest intervals (PHI) and re-entry intervals (REI).  The risk of disease or insect resistance is lower, and in some cases, they can improve the efficacy of other products. Biologicals are often classified as having multiple modes of action, giving them an advantage over a conventional pesticide that only works in one way. Some examples of different modes of action include competition with pathogenic organisms, inducing plant defenses, causing mycoparasitism, and others. There are drawbacks to biological products.  As a rule, biopesticides do not work well in environmental extremes or under high disease pressure.  They are best used when pest pressure is low or as a preventative.  Biologicals are not considered a cure for plant disease or a silver bullet to banish all insects.  In most cases, the shelf life of biological products is shorter than that of conventional pesticides. 

Too good to be true?

Sometimes, advertising and marketing sound wonderful when a new product comes out.  You may be tempted to invest and use the new product to replace other products.  Be careful!  Set up a comparison on your farm.  Use the new product in one row or a specific portion of a crop.  Take notes about what you see.  If the product shows promise, slowly integrate it with your existing products.  Also, it is worthwhile to figure out how much the product costs per application and how many pathogens/insects may be managed.

If you are new to biologicals, use the biopesticide profiles recently created by Amara Dunn-Silver, a biocontrol specialist with the New York State Integrated Pest Management Program. The profiles include practical information such as UV tolerance, shelf life, tank-mixing, rainfastness, and toxicity concerns for beneficials, including bees. The profiles are not meant to replace the labels but as guidance when choosing a new product.

If you solely rely on conventional chemical pesticides to keep diseases and insects at bay, you are missing out. Consider adding biopesticides to your spray cabinet. There are a multitude of options for bio-insecticides, miticides, and fungicides. Using products that work on multiple modes of action and act against resistance issues is a benefit you want on your farm.