THE GROWER, Vance Publishing Corporation
Written by Dr. Pamela Marrone, founder and chief executive officer of Marrone Bio Innovations, Davis, Calif.
EDITOR’S NOTE: This is a guest column and opinions expressed here are only those of the author and do not necessarily reflect those of Vance Publishing Corporation.
Now more than ever, fruit and vegetable growers need effective and environmentally sustainable pest management programs to protect against crop diseases, improve food yields and quality, and feed a growing and increasingly food-conscious world.
Biopesticides or “biologicals” are becoming an important tool in the grower’s toolbox by promoting plant health and controlling unwanted pests and diseases, leading to better yields with reduced environmental impact – as well as an improved bottom line for growers.
What are ‘biologicals’?
Made from naturally occurring substances, such as microorganisms, plant extracts, fatty acids or pheromones, biologicals can also play a role in helping growers address consumer issues such as worker safety, toxicity to wildlife, air pollution, and surface and groundwater contamination. Biopesticides break down quickly and efficiently in the environment, leaving little chemical traces.
Although they can be effective as a standalone treatment, most biopesticides are used in conjunction with traditional chemicals as part of an integrated pest management program. Here, their efficacy and quality are enhanced compared with chemical-only programs, especially for crops like fruits, vegetables, nuts and ornamentals.
Biopesticides are considered among the best low-risk and most effective tools for achieving crop protection in IPM systems. Research, field trials, and performance history prove that the most effective IPM programs typically consist of biopesticides used in combination tank-mixes or in rotation with conventional chemical products.
Typically, biopesticide field trials conducted by consultants or university researchers compare a biological standalone to the best chemical treatments, which may include tank-mixes. If the standalone biological is not as effective as the chemical(s), often the work stops there and the results reported, “The biological did not work as well as the chemical(s).”
Take an integrated approach
Therefore it is critical to integrate the biological into the program and not just assess them standalone. Very often the integrated program results in marketable yields and quality that can exceed chemical-only programs.
Even if the results are the same as the chemical-only program, the program is enhanced with the ability to manage residues, delay resistance, increase labor flexibility and enhance beneficials.
The key to maximizing the performance of biopesticides and IPM programs is to understand the modes of action of the biological compared to the chemical. Best use is understanding how they work, rather than asking, “Do they work?”
Many biopesticides are slower acting than chemicals and can take several days to see pest mortality. Some stop feeding, reduce reproduction and inhibit molting.
Counting just pest mortality rather than measuring crop damage, yields or season long population suppression, may mask the overall benefits to the program. Biofungicide use in an integrated program can often result in increased marketable yields while overall percent disease control is less than the chemicals in standalone trials.
Take a program approach
When used in IPM programs, biopesticides offer additional benefits, such as complex and novel modes of action for resistance management to extend the product life of conventional pesticides. Biologicals provide flexibility to traditional farming operations with reduced pre-harvest intervals to manage residues for exported produce, as well as shorter field reentry times for workers—ultimately reducing labor costs.
Biopesticides can also provide high margins of safety for applicators, farm workers and rural neighbors and typically have shorter field restricted-entry intervals, which makes it easier for farmers to complete essential agronomic practices on a timely basis and schedule harvests.
Biopesticides notably target specific pests without disrupting the beneficial components of the surrounding ecosystem. Although many insect species have a negative effect on crop production, some species, such as honeybees, predators and parasitoids, can have a positive effect.
These benefits may derive from the insect’s role as a pollinator or by acting as a natural predator to the insects causing damage.
Pest resistance to conventional chemical pesticides is another significant concern to the agricultural industry. As new classes of reduced-risk chemistries continue to be introduced to commercial growers, the challenge of resistance management must be met with thoughtful use of diverse, season-long pest control programs.
Whether used alone or in combination with conventional pesticides, biopesticides offer an important tool for enabling grower’s to effectively promote plant health, control unwanted pests and feed a growing population with reduced environmental impacts – while also improving profitability.