Campus Units

Electrical and Computer Engineering, Plant Pathology and Microbiology

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

8-14-2018

Journal or Book Title

Plant Disease

DOI

10.1094/PDIS-02-18-0222-RE

Abstract

The objective of this study was to determine the effects of ILeVO (fluopyram) and VOTiVO (Bacillus firmus I-1582) seed treatments on Heterodera glycines second-stage juvenile (J2) root penetration and behavior. In a growth chamber experiment, roots of soybeans grown from treated or untreated seeds were inoculated with H. glycines J2s at soil depths of 2.5, 5, or 7.5 cm. ILeVO significantly reduced H. glycines root penetration, compared to the untreated control, but only when J2s were inoculated at a soil depth of 2.5 cm, which was near the seed. Changes in nematode behavior were assessed by collecting 60-second videos of J2s after two hours of exposure to exudates from treated seeds or radicles from treated seeds or from soil leachates in which treated seeds were planted. X- and y-coordinates of each of the 13 reference points were recorded every hour for twenty-four hours. A custom program analyzed and transformed the coordinates into nematode motion parameters (speed and total change in curvature). ILeVO, but not VOTiVO, seed exudates significantly reduced J2 speed relative to the untreated control. Soil leachates from ILeVO or VOTiVO treatments had no consistent effect on H. glycines speed or total change in curvature compared to the untreated control. In another experiment, treated or untreated seeds were incubated in wells of 6-well tissue culture plates containing 11.5 percent Pluronic gel. Seeds were removed after two hours and approximately 50 J2s then were pipetted in each well. The plates were scanned every 60 minutes for 24 hours, and the number of J2s in each well that moved a minimum distance of ≥ 300 μm was determined using another custom software program. ILeVO, but not VOTiVO, significantly reduced the movement of J2 populations relative to control wells in which no seeds were added. And wells that had seeds, treated or not, yielded significantly less J2 movement compared with the no-seed control. The results of these experiments indicate that ILeVO reduces activity on H. glycines J2s but may not affect nematodes beyond a limited area surrounding the treated seed.

Comments

This is a manuscript of an article published as Beeman, Augustine, Zach Njus, Santosh Pandey, and Gregory L. Tylka. "The effects of ILeVO and VOTiVO on root penetration and behavior of the soybean cyst nematode, Heterodera glycines." Plant Disease (2018). doi: 10.1094/PDIS-02-18-0222-RE. Posted with permission.

Copyright Owner

The American Phytopathological Society

Language

en

File Format

application/pdf

Available for download on Wednesday, August 14, 2019

Published Version

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