Ultimately, beneficial fungi could be more effective than pesticides against nematodes

February 04, 2021

Over the past 30 years, the use of soil fumigants and nematicides used to protect cole crops, such as broccoli and Brussel sprouts, against cyst nematode pathogens in coastal California fields has decreased dramatically. A survey of field samples in 2016 indicated the nematode population has also decreased, suggesting the existence of a natural cyst nematode controlling process in these fields.

Thanks to California's pesticide-use reporting program, nematologists have been able to follow the amounts of fumigants and nematicides used to control cyst nematodes over the past three decades. "Application of these pesticides steadily declined until they were completely eliminated in 2014 while, for example, broccoli yields continued to increase each year," said Ole Becker, a scientist with the Department of Nematology at the University of California.

In a study of 152 fields, Borneman, Becker and colleagues detected cyst nematodes in about 38% of them. Only a few of these fields had enough nematodes to potentially damage the crops. This showed that growers had likely reduced their usage of nematicides because of a natural decline in the nematode populations.

To identify the cause of this natural decline, Borneman, Becker and colleagues used cyst nematodes as a bait and found that a diverse population of fungi were likely killing the nematodes. The most abundant genus was Hyalorbilia, which contains species previously described as effective parasites of cyst and root-knot nematodes.

"The results from our baiting analysis combined with advanced molecular tools gave us a detailed depiction of the possible nematode-parasitizing fungi in these soils, which then provided a plausible explanation for this dramatic decrease in pesticide use," said Borneman.

Their research demonstrates the usefulness of monitoring plant-parasitic nematode density before using nematicides and increases the awareness of beneficial fungi in crop protection. These fungi might be considered as possible biological control agents for nematodes.
-end-
To learn more, read "Heterodera schachtii Females Using a Baiting Experiment with Soils Cropped to Brassica Species from California's Central Coast" published in the January issue of .

American Phytopathological Society

Related Nematodes Articles from Brightsurf:

Oil-eating worms provide valuable assistance in soil remediation
Bionanotechnology Lab of Kazan Federal University works on adapting nematodes to consuming oil waste.

Fungal species naturally suppresses cyst nematodes responsible for major sugar beet losses
In the current study, the authors showed that similar fungi inhabited sugar beet fields in California, suggesting that a group of naturally occurring fungi, given the right conditions, might be able to dramatically reduce nematode populations in one season.

The balancing act between plant growth and defense
Kumamoto University researchers have pinpointed the mechanism that regulates the balance between plant growth and defense.

Fungus application thwarts major soybean pest, study finds
The soybean cyst nematode sucks the nutrients out of soybean roots, causing more than $1 billion in soybean yield losses in the U.S. each year.

WSU genetic discovery holds implications for better immunity, longer life
Wrinkles on the skin of a microscopic worm might provide the key to a longer, healthier life for humans.

How nematodes outsmart the defenses of pests
The western corn rootworm, one of the world's most damaging maize pests, can use plant defense compounds to defend itself against its own natural enemies, so-called entomopathogenic nematodes.

Research suggests fumigants have very low long-term impact on soil health
It started with curiosity. How does a fumigant, commonly used for nematode management in potato cropping systems, influence soil microbial communities?

New survey confirms muscadine grapes are affected by parasitic nematodes
Muscadines are also known for being hearty grapes, with a tough skin that protects them from many fungal diseases.

Otherworldly worms with three sexes discovered in Mono Lake
The extreme environment of Mono Lake was thought to only house two species of animals -- until now.

New information on regulation of sense of smell with the help of nematodes
PIM kinases are enzymes that are evolutionarily well conserved in both humans and nematodes.

Read More: Nematodes News and Nematodes Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.