Soybean cyst nematode resistant soybeans help with control–but only with rotation

In Delta Farm Press

New University of Missouri Extension plant pathologist Kaitlyn Bissonnette brings research on soybean cyst nematode (SCN) management to Missouri.

SCN numbers are growing in Missouri as farmers devote more acres to soybean production. SCN infests about 75 percent of Missouri fields, according to a recent survey by MU College of Agriculture, Food and Natural Resources researcher Melissa Mitchum. Many of these fields have high SCN egg counts. Continue reading

Corn gene associated with disease resistance

from North Carolina State University via EurekAlert!

Researchers at North Carolina State University have found a specific gene in corn that appears to be associated with resistance to two and possibly three different plant leaf diseases.

In a paper published this week in Nature Genetics, NC State researchers pinpoint the gene – caffeoyl-CoA O-methyltransferase – that seems to confer partial resistance to Southern leaf blight and gray leaf spot, and possibly to Northern leaf blight, a trio of diseases that cripple corn plants worldwide. Continue reading

New gene for atrazine resistance identified in waterhemp

Waterhemp has been locked in an arms race with farmers for decades. Nearly every time farmers attack the weed with a new herbicide, waterhemp becomes resistant to it, reducing or eliminating the efficacy of the chemical. Some waterhemp populations have evolved resistance to multiple herbicides, making them incredibly difficult to kill.

Adding to the challenge is the fact that waterhemp can evolve resistance in at least two ways. In target-site resistance, a gene mutation changes the protein that the herbicide is designed to attack. With an ill-fitting protein binding site, the herbicide becomes ineffective. The plus side of target-site resistance is that it is relatively easy to identify using standard lab procedures. Continue reading

Plant signals travel different routes to turn on defense

By Katie Pratt, University of Kentucky

Faced with a pathogen, important signaling chemicals within plant cells travel different routes to inform the plant to turn on its defense mechanisms, according to a recent University of Kentucky study.

Plant pathologists Aardra and Pradeep Kachroo study how plants fend off secondary infections, a defense mechanism known as systemic acquired resistance. In previous studies, the UK College of Agriculture, Food and Environment scientists identified several chemicals within plant cells that help trigger this resistance. Their most recent study, published in Cell Host and Microbe, looked at the paths three of those chemicals travel. Understanding these pathways and chemicals may shed light on new ways scientists can help plants fend off a wide range of pathogens. Continue reading

Pests can develop resistance to non-chemical control methods

By Richard Levine

Agricultural pests, such as insects and weeds, can be incredibly adept at developing resistance to control methods. When you mention the word “resistance,” most people probably think of pests becoming resistant to certain chemicals — weeds becoming herbicide resistant, or insects becoming resistant to insecticides, for example.

However, there are many other types of resistance. Dr. Alison Van Eenennaam, the 2014 recipient of the Borlaug CAST Communication Award, recently explained that weeds can become resistant to mechanical control methods — such as mowing or tilling.

See the rest of the story at Entomology Today.

When You Can’t Kill What’s Bugging You

When I use a pesticide to get rid of what’s “bugging” me, I assume it will work. Most of the time, it does.

Continue reading