New Biopesticide Features New Mode of Action

 

Thankfully, at least in the agricultural industry, improvements in technology, techniques and pest control have allowed farmers to expand crop production on the limited arable land available.

 

This spring, a new biofungicide will launch that features a unique mode of action that may aid farmers and industry with their work.

 

The biopesticide spray, Lifegard WG biological plant activator (trade name Lifegard), induces plants to switch on resistance genes, causing metabolic responses to stop infections and diseases from developing in a phenomenon known as systemic acquired resistance, or SAR. Most plants have those genes.

 

The naturally occurring bacterium, Bacillus mycoides isolate J, or BmJ, represents a "new class of biological disease control agents with a new mode of action that could save farmers worldwide millions of dollars in lost revenue," says Mike Dimock, director of field development at Certis USA, which will manufacture and market the biofungicide.

 

To ensure productive crops, most farmers use synthetic pesticides to control crop-destroying pests. But in the past 20 years, farmers increasingly have recognized the need for other methods for pest control that are safer for the environment and the land, says BCC Research analyst Jason Chen.

 

In Global Markets for Pesticides, Chen reports farmers are turning to biopesticides to prevent pest damage in a more ecologically friendly manner. "The increasing global demand for organically grown food, growing awareness of our environment and the harmful effects of pollution and health hazards from many conventional pesticides are really galvanizing producers in this industry. Fungicide resistance management is going greener, definitely."

 

To help farmers and industry along with their goal of using fewer industrial chemicals to control plant diseases, Barry Jacobsen, a plant pathologist and associate director of agriculture at Montana State University, discovered BmJ in 1994 when researching Cercospora leaf spot disease.

 

The fungus typically causes brown spots on the older, lower leaves of trees. Bright yellow, orange or red colors mottle the leaves before it falls from the tree, usually in the mid-to-late summer months. The disease is particularly ruinous to beet plants.

 

 

The discovery turned  on the NPR1 gene, which is found in most plants. As reported by Sepp Jannotta, the activation of the NPR1 gene causes a process in the plant called induced resistance.

 

"Within five minutes of that bacillus spore being on the plant leaf, the plant knows it's there and it starts its defense reactions," Jacobsen tells Jannotta. "It reacts by producing hydrogen peroxide and some other things and this thickens cell walls and makes it more difficult for a pathogen to infect. Within a day it starts to produce enzymes that attack fungi and bacteria. And it's very effective on viruses as well."

 

While some microbial biofungicides have been reported to also have moderate SAR activity, BmJ is unique in that it works entirely as a microbial SAR activator with no direct antagonistic effect on plant pathogens.

 

“It is an example of what we call induced resistance,” Jacobsen tells Farm and Ranch guide. “I would say it reminds me of using a vaccination.” In that article, Jacobsen says BmJ "induces the same genetic resistance pathway as the class of chemical SAR inducers, known as benzothiadiazoles, but for longer periods and with lower risk of phytotoxicity."

 

“Because BmJ acts so differently from most fungicides, with no direct action against a specific pathogen target site, it has great potential for use in disease management programs designed to reduce the risk and consequences of fungicide resistance,” Dimock adds. “In fact, Dr. Jacobsen’s fieldwork over the past decade has already demonstrated the utility of BmJ in programs for management of fungicide-resistant Cercospora leaf spot in sugarbeets. We expect to see similar benefits in other crops where resistance to conventional fungicides presents a serious challenge.”

 

Lifegard, scheduled for market release in Spring 2017, was recently approved by the Organic Material Review Institute for use in organic production.