The use of botanical oils to protect plants is as old as the plants themselves. Plants developed these complex substances over millennia to repel or kill feeding insects and harmful fungi and bacteria.
Botanicals used to be the main way humans protected themselves and their crops from harmful pests, until the advent of synthetic pesticides during World War I. Now, amid concerns that the synthetic chemicals are posing adverse risks to human and environmental safety, along with the development of insect and fungal resistance, botanicals have come full circle and represent the future of agricultural pest control.
But to Steve Bessette, Vice-President of the Botanicals division at KeyPlex, it just makes sense.
“It’s not that unusual to look at natural products for the future, because even things like imidacloprid, a neonicotinoid, was started from nicotine,” Bessette says. “Researchers looked at the nicotine molecule and said, ‘How can we tailor this?’ That’s also how synthetic pyrethroids got started from natural pyrethrum found in the chrysanthemum plant.”
And with more advanced technology than at any time in the past, the secrets of how these ancient substances work are being discovered. Bessette’s team at KeyPlex invested $15 million and seven years into researching exactly what compounds are responsible for the pesticidal properties of essential oils such as peppermint, rosemary and geraniol.
“Most of the folks that tried to do things with botanicals in the past would go into the garage, put some mixtures together and try to market it,” Bessette says. “We did the opposite. We said, ‘Let’s break rosemary oil down to its 15 pure compounds and start looking at those individually and how they work.’”
Botanicals Offer New MOAs
What Bessette’s team found was a compound in the oils that mimicked the chemical structure of a neurotransmitter found only in insects called octopamine. The compound would bind to the octopamine receptor, blocking the actual neurotransmitter and disrupting the insect’s nervous system and downstream signal pathway. What’s more, trials showed that all stages of the insect’s life cycle were affected. The team also discovered that beneficial insects and the plants have evolved to where the beneficials are less susceptible to the botanical compound. A new product, Ecotrol, was developed as a result.
And this is just one compound in a few plants. Bessette says the possibilities are unlimited.
“I believe we’ve just scratched the surface of botanical chemistry,” he says. “If you think of the number of botanical compounds that exist, they number in the hundreds of thousands, if not millions. At KeyPlex, we’re now looking at alternative modes of action for other chemistries. We’re also looking at advanced screening systems. This is an ideal way to say, ‘I know this structure will target this receptor, and then start doing high-throughput screening based on known properties. I could screen 2,000 compounds a month and identify which ones have the capacity to bind at that receptor site. It’s a shortcut to developing new chemistries down the road. If I know what the structure’s activity is, I can screen in one month what might otherwise take years.”
Better Formulations Boost Efficacy
Formulations are getting better too. “Once you understand the mode of action, you can start to plan the formulations effectively,” Bessette says. “Most people don’t realize botanicals are completely different from conventional synthetic chemistries when it comes to formulation.”
Synthetic chemistries are usually single-molecule and much easier to formulate than the more complex botanicals that may contain up to 20 different compounds, Bessette says. The first priority is to learn the mode of action. The second is to formulate it in a way to make it applicable for coverage in a cost-effective and competitive way.
Gerald O’Connor, President of KeyPlex, says the future of botanicals is bright.
“For me, the future is a new wave of eco-friendly products that can be introduced into the market without huge resistance and that we know work well,” he says. “Many times there is a long adoption period for new products, because growers aren’t sure it will work.
“People will see Ecotrol work right out of the gate,” O’Connor says. “Does it work for six weeks straight? No. But if it gets to three to four weeks control and we keep developing from the baseline we have, I believe we can get greater efficacy than the standard single-molecule chemicals. That may take time, but that’s why I’m so excited about this.”
Looking to the Future
The next phase, O’Connor says, is to use KeyPlex’s high-end nutritional products to actually pull the more volatile botanical compounds inside the plant structure. It will not only produce a longer residual activity for the botanical compound, it will combine with the known ability of KeyPlex fertilizers to trigger the plant’s own SAR (Systemic Acquired Resistance) response.
“If we can do this, we’re not just talking about insects. We’re now talking about disease control within plants,” O’Connor says.
This isn’t such a far-fetched idea. Bessette says they’ve already done it. Ecotrol was mixed with a KeyPlex nutritional product and applied to apple trees infected with a fungus. The tree absorbed the fertilizer and with it the more difficult-to-absorb botanical molecule. Once inside the tree, the Ecotrol killed the fungus and the trees recovered.
“This is where I think the future is,” says Bessette. “We will get better at and smarter about delivering plant essential oils that we know have activity. We have tons of data about the anti-fungal, anti-bacterial and insecticidal activity of botanical compounds. These are published, peer-reviewed studies. Once we get better at delivery, you’re going to see the activity really expand and growers will find new and better ways to use these compounds more effectively.”