Helping Plants Help Themselves
Turning on plant defenses gives growers new tool
May 8, 2012
You know that if you take your vitamins, eat right and get enough sleep, you get sick less often. In some ways, the same is true for plants; a plant with a healthy root system, an optimum growing environment and plenty of stored energy is much better able to weather stress than one that’s already living on the edge. Obviously, maintaining ideal levels of nutrients, light, water and humidity are key to keeping plants healthy. But plants are not entirely helpless. They have physiological defenses of their own that, when triggered, allow them to endure and recover from drought and temperature stress and resist disease. Having the ability to trigger this response would be a powerful tool for growers, and research in this area is ongoing. Some of the results have been fascinating and you should expect to see more developments in this direction.
BASF’s Pageant Intrinisic brand fungicide is the first in the ornamental world allowed by the EPA to list “plant health” on the label. Research has shown that in many cases, Pageant Intrinsic does offer plant health benefits, especially in cases of short term temperature or drought events. Although the product is a fungicide, Pageant Intrinsic provides a boost to plants, helping them to store more energy that is then available in times of stress.’
How does it work?
Pageant Intrinsic kills fungi by inhibiting mitochondrial respiration, the process by which fungi break down carbon into energy for growth. It does the same thing for plants, the difference being that in plants, it produces a positive effect.
“Conserving carbons during respiration is at the core of it,” says Kathie Kalmowitz, market development specialist for BASF. “Those carbons, instead of being used up during respiration, are now being shuttled to the roots. So if you go into a drought or into high heat, those roots are able to take the plant through that stress.”
The decrease in respiration also triggers a chain of positive physiological changes: increased levels of antioxidants and defense-signaling compounds and a decrease in the stress hormone ethylene. In addition, it increases the activity of nitrate reductase, the enzyme responsible for making a form of nitrogen that can be used by plants, resulting in more nitrogen available for plant growth.
Because Pageant Intrinsic was being produced and used as a fungicide, BASF researchers were not initially looking for plant health benefits. But they began to see evidence that something else was happening after the fungicide was applied.
“They already knew some of these pathways in the plant were being turned on when pyraclostrobin was applied,” Kalmowitz says. “The anecdotal evidence [of plant health benefits] and some of the observations we were told about have helped guide our further research in this area about how to apply it to the ornamental space.”
Kalmowitz says the crop side of the company did a lot of work initially, and because many of the crops have “sister” plants in the ornamental world, they were able to use some of their leads.
“However, since we are a distinct industry and market, we developed a lot of our own data. All told, BASF has been working in this area for about ten years. In the ornamental area, it’s about four years,” Kalmowitz says.
Robin Siktberg is a contributing editor for Meister Media Worldwide. You can eMail her at email@example.com.