Soybean Sentinel Plot Report: June 18, 2019

Our soybean sentinel plot report this week reveals that minor populations of bean leaf beetles and slugs are active, and Septoria brown spot has begun.

Background on the project:

For eighth consecutive season, the Pennsylvania Soybean Promotion Board is funding a Soybean Sentinel Plot Program, which is being managed by The Dept. of Entomology at Penn State and executed by Penn State Extension. In this effort, Penn State Extension Educators are regularly scouting 30 or so ‘typical’ soybean fields in twenty-three counties across the state, reporting the populations of plant pathogens and insect pests that they find. Our goal is to inform the agricultural community which pests are active across the state, so folks will have a sense of what to expect when they scout their own fields as part of an IPM program. It would be inappropriate to use these reports to justify insecticide applications.

 

 

In the reports below, pests that were found during scouting are listed with their severity, which is rated on a 1-10 scale with 10 being the highest. A severity score of 1 equates to 10% or less infestation or defoliation, a “2” aligns with 20% or less infestation or defoliation, and so on. Growers should be sure to check their own fields to determine your local populations, but these reports will indicate which pests are likely to be active in fields. Our reports are distributed via this weekly newsletter and are available via the Penn State Extension website (then search for “soybean sentinel plot”).

Figure 1: As weather remains wet, feeding by slugs is becoming more evident on young soybean plants. Slug damage is distinctive because slugs usually remove the top tissue layers, leaving white areas that often do not penetrate entirely through the leaf. This damage is often accompanied by slime trails (Photo by Adriana Murillo-Williams, Penn State Extension).

Summary of reports:

The reports this week indicate low pest populations in the soybean fields that we are scouting. Soybean fields range from VC to R1, reflecting the variability evident across the state. Only two invertebrate pests, bean leaf beetle and slugs (Figure 1), were noted this week and only one disease, Septoria brown spot. All three pests were in low abundance and should not require any management. Of course, if wet weather continues slugs and some other pathogens are likely to emerge as more significant issues. Happy scouting!

18 June 2019 – Franklin County – Brittany Clark

Growth stage: R1

  • Minor feeding by bean leaf beetle and slugs
  • No diseases noted

17 June 2019 – Butler County – Justin Brackenrich

Two fields

Growth stage: V2-3

  • Bean leaf beetle – Severity: 1
  • Lady beetles present
  • Septoria brown spot – Severity: 1

17 June 2019 – Beaver County – Justin Brackenrich

Growth stage: V2

  • Lady beetles present
  • No diseases noted

 

 

17 June 2019 – Bradford County – Casey Guindon

Growth stage: VC

  • Bean leaf beetle – Severity: 1
  • Slugs – Severity: 1
  • No diseases noted

17 June 2019 – Crawford County – Joel Hunter

Growth stage: V2

  • No insects or slugs noted
  • Deer and groundhogs active!
  • No diseases noted

17 June 2019 – Montgomery County – Andrew Frankenfield

Growth stage: VC

  • Minor feeding by bean leaf beetle and slugs
  • No diseases noted

17 June 2019 – Cambria County – Zach Larson

Near Williamsburg

Growth stage: V3

  • Bean leaf beetle – Severity: 1
  • No diseases noted

14 June 2019 – Northumberland County – Anna Busch

Growth stage: R1

  • Bean leaf beetle – Severity: 1
  • Bacterial blight – Severity: 2
  • Septoria brown spot – Severity: 1

14 June 2019 – Bedford County – Zach Larson

Near Cessna

Growth stage: V1

  • Bean leaf beetle – Severity: 1
  • Slugs – Severity: 1
  • No diseases noted

14 June 2019 – Cambria County – Zach Larson

Near Loretto

Growth stage: V1

  • Bean leaf beetle – Severity: 1
  • No diseases noted

14 June 2019 – Lebanon County – Marie Bryant and Del Voight

Five fields

Growth stage: V3-V10

  • Bean leaf beetle – Severity: 1-2 depending on field; reported from each field
  • Black cutworm damage – Severity: 1; reported from one field
  • Septoria brown spot – Severity: 1-3 depending on field; reported in four fields

14 June 2019 – Lancaster County – Marie Bryant and Del Voight

Near Landisville

Growth stage: V3-V10

  • Bean leaf beetle – Severity: 1
  • Black cutworm damage – Severity: 2
  • Septoria brown spot – Severity: 2

18 June 2019 – Lancaster County – Jeff Graybill

Near Manheim

Growth stage: V5

  • No insects noted – bean leaf beetles are no longer present
  • No diseases noted

12 June 2019 – Dauphin County – Liz Bosak

Growth stage: V2

  • Bean leaf beetle – Severity: 1
  • No diseases noted