Basic microbiology research study unexpectedly uncovers practical findings for growers

Basic microbiology research study unexpectedly uncovers practical findings for growers.
Cover cropping also has its risks, especially if dying cover crops encourage disease pressure that passes on to the next crop.
Such is the unexpected lesson behind a recent study published in Phytobiomes, a new open-access journal of The American Phytopathological Society.
In this recently-published article, titled "Isolation of Cultivation-Resistant Oomycetes, First Detected as Amplicon Sequences, from Roots of Herbicide-Terminated Winter Rye," Dr. Matthew G. Bakker and several other researchers at the U.S. Department of Agriculture’s Agricultural Research Service set out to describe the microbiology of dying rye cover crop roots and how their microbial communities changed over time in a field setting.
Among the many microorganisms detected, they found that several less-known species of oomycetes, including Pythium and Lagena species, were commonly associated with cereal rye cover crops.
While this research was originally meant to be basic, the study unexpectedly turned out to have some very practical findings.
In addition to describing and validating the microbiology of these rye cover crop roots, their work revealed that the Pythium species naturally passed on to the corn plants as they sprouted into seedlings, resulting in seedling disease.
"This study tells a neat story about how new research techniques can lead to unpredictable findings with important and practical applications," said Bakker.
"Another interesting aspect of this study was that the most abundant species of Pythium in the cover crop roots was different on one side of the field than on the other.
Other benefits of this study include… An improved understanding of the microbiology of dying plants in natural and managed ecosystems The demonstrated importance of using DNA technology to help detect the microbial communities associated with crops, as microorganisms can be difficult to cultivate in the laboratory An improved understanding of the ecology of oomycetes — and of the potential for shared pathogens between cover crops and grain crops Bakker hopes this and similar work will spark more research in root-soil dynamics.

Snap beans hard to grow in cover crop residue

Snap beans hard to grow in cover crop residue.
"We designed a study to look at a scenario that had a better chance of success.
We used snap bean, which is relatively large-seeded, and planted later to allow sufficient time to grow and then kill a cover crop."
In both Illinois and Washington, Williams and USDA-ARS agronomist Rick Boydston grew vetch, rye, and a combination of the two cover crops before killing them with a roller-crimper — a machine that evenly flattens and crimps standing plant biomass — or with a combination of the roller-crimper and a burndown herbicide.
Instead, vetch became weedy and caused yield losses in snap bean.
"Another issue was adequate seed-to-soil contact, which can become a challenge with excessive plant residues on the soil surface.
No-till snap bean performance and weed response following rye and vetch cover crops.
"Snap beans hard to grow in cover crop residue."
University of Illinois College of Agricultural, Consumer and Environmental Sciences.
"Snap beans hard to grow in cover crop residue."