PLATTEVILLE, Wis. — Farmers could benefit from massage and aromatherapy, but not just for the purpose of relieving stress from the harvest.
Their soybeans stand to benefit, too, and new research from a University of Wisconsin-Platteville student indicates that essential oils — compounds that are derived from plants such as cinnamon and thyme — could help reduce or prevent infection by a destructive fungus.
“Pretty much all plant disease management up to this point uses chemically derived fungicides and pesticides,” said junior Joseph Creanza, who is studying soil and crop science.
Creanza and his advisor Muthu Venkateshwaran are investigating the antifungal properties of essential oils, which are widely used in personal care products such as massage oils and cosmetics.
The first stage of Creanza’s research, which began earlier this year, determined the concentrations of essential oils that could be applied to the plants without causing damage.
Now, he is investigating which oils are most effective at inhibiting the infection of young soybean plants by white mold, a common pathogen in the Midwest that can be the bane of farmers in the late summer when the weather is hot and humid.
“This particular plant disease does have large economic impacts,” Creanza said.
To do this, he sprays sets of plants with one of 11 types of essential oils, leaving a few plants untreated to use as comparisons.
After three days, Creanza clips the tops of the plants and infects the plant with white mold. Another week passes before he measures the damage the fungus has caused.
The mold travels down the stem, hollowing out the plant in its wake. The soybean leaves shrivel and fall to the bottom of the jar in which they are growing.
Creanza photographs and palpates each plant to assess its condition.
Next year, collaborators in UW-P’s chemistry department will try to modify the chemical structure of essential oils to increase their efficiency and permeability, so as to increase the plant’s absorption of the oils.
“They are effective against bacteria,” Venkateshwaran said. “They are effective against fungal pathogens, but … it might be more effective against one more than the other because fungal pathogens are not all the same.”
Although existing fungicides are highly effective, there are advantages to using essential oils, Creanza said.
“It’s definitely more environmentally friendly,” he said. “These essential oils can be derived from plants. … You can mass-produce plants.”
Pathogens also can become resistant to conventional fungicides.
Creanza’s research earned state recognition earlier this year at the 2020 Student Research and Innovation Showcase, sponsored by WiSys, a nonprofit organization that advances applied scientific research throughout the UW System.