For a very long time now, organic gardeners have believed that plants have self-defense mechanisms that work against insects and diseases. A plant is attacked and it defends itself by releasing hormones or biochemicals.
This has been confirmed in multiple experiments now with regard to insects and now, thanks to the USDA, research on plant responses to fungal infections is also proven.
Scientists working with corn found the plants produced zealexins and kauralexins (volatile organic compounds) to fight back when attacked by fungus. Both of these products are derived from forms of Terpenes (another chemical) and scientists have been studying Terpenes for some time because they’re produced under insect attack.
So now we know plants have defense systems for both insect and fungal attacks.
In practical terms, this means if we keep our plants healthy, they’ll produce the basic products to fight off attacking insects and diseases. It’s only when we allow our plants to be stressed that we can expect the insects and diseases to win (in the average scenario)
So your job as a gardener is to reduce plant stress.
And herein lies the challenge of gardening – creating conditions plants love enough to grow strongly and stress free. Want to bet they’ll discover organic gardening does a better job of this than anything else?
Originally published in January 2012 issue of Agricultural Research