Soybean Sentinel Plot Report for September 4, 2018

With soybean maturity approaching in most fields, insects and diseases are becoming less relevant, but most pest populations remain low.
Soybean Sentinel Plot Report for September 4, 2018 - News

Updated:

Mature soybean field in Centre County. Image Credit: Adriana Murillo-Williams

Our reports this week from 8 counties across Pennsylvania counties indicate that populations of insects and pathogens continue to be low. Most fields have reached growth stage R5 or later, so insect feeding is becoming less relevant. For pathogens, Septoria brown spot, frog-eye leaf spot, downy mildew, and white mold are being found. Keep in mind that insects and pathogens generally do not alter soybean yield after growth stages R6 and R3, respectively.

This growing 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 25 or so ‘typical’ soybean fields in twenty counties across the state, reporting the populations of plant pathogens and insect pests that they find. Our goal is to inform folks which pests are active across the state, so that they 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”).

Scouting Reports

4 September – Crawford County – Joel Hunter

Growth stage: R6

  • Japanese beetle – Severity: 1
  • Mexican bean beetle – Severity: 1
  • Soybean aphid – Severity: 1
  • Septoria brown spot – Severity: 1

4 September – Union County – Anna Busch

Growth stage: R5

  • Green cloverworm – Severity: 1
  • Soybean aphid – Severity: 1
  • Silver-spotted skipper caterpillar – Severity: 1
  • Lady beetles abundant
  • Soybean downy mildew – Severity: 1
  • Septoria brown spot – Severity: 1

4 September – Northumberland County – Anna Busch

Growth stage: R7

  • Bean leaf beetle – Severity: 1
  • Grasshoppers – Severity: 2
  • Lady beetles abundant
  • Soybean mosaic virus – Severity: 1
  • Frogeye leaf spot – Severity: 1

2 September – McKean County – Nicole Carutis

Two fields

Growth stage: R5

  • Japanese beetle – Severity: 1
  • Grasshoppers – Severity: 1
  • Soybean aphid – Severity: 1
  • Lady beetles abundant
  • Frogeye leaf spot – Severity: 1
  • Soybean downy mildew – Severity: 1

2 September – Potter County – Nicole Carutis

Two fields

Growth stage: R4-5

  • Grasshoppers – Severity: 1
  • Japanese beetle – Severity: 1
  • Brown marmorated stinkbug – Severity: 1
  • Soybean aphid – Severity: 1
  • Lady beetles abundant
  • White mold – Severity: 1
  • Frogeye leaf spot – Severity: 1
  • Septoria brown spot – Severity: 1
  • Soybean downy mildew – Severity: 1

31 August – Blair County – Zach Larson

Growth stage: R6

  • Green stink bug – Severity: 1
  • Soybean aphid – Severity: 1
  • Bean leaf beetle – Severity: 1
  • Japanese beetle – Severity: 1
  • Grasshoppers – Severity: 1
  • Septoria brown spot – Severity: 1
  • Frogeye leaf spot – Severity: 1
  • White mold – Severity: 1
  • Soybean downy mildew – Severity: 1

30 August – Cambria County – Zach Larson

Growth stage: R6

  • Soybean aphid – Severity: 1
  • Bean leaf beetle – Severity: 1
  • Japanese beetle – Severity: 1
  • Lady beetles abundant
  • Septoria brown spot – Severity: 1
  • Frogeye leaf spot – Severity: 1
  • Soybean sudden death syndrome – Severity: 1

30 August – Armstrong County – Rachel Milliron

Two fields

Growth stage: R5-6

  • Japanese beetle – Severity: 1
  • Grasshoppers – Severity: 2
  • Brown marmorated stink bug – Severity: 1
  • Lady beetles abundant
  • Septoria brown spot – Severity: 2
  • Frogeye leaf spot – Severity: 2

30 August – Bradford County – Casey Guindon

Growth stage: R5

  • Japanese beetle – Severity: 1
  • Lady beetles abundant
  • Septoria brown spot – Severity: 1
  • Frogeye leaf spot – Severity: 1
  • White mold – Severity: 1

29 August – Butler County – Justin Brackenrich

Growth stage: R5

  • Grasshoppers – Severity: 1
  • Japanese beetle – Severity: 1
  • Lady beetles abundant
  • Soybean sudden death syndrome – Severity: 1
  • Alfalfa mosaic virus – Severity: 1
  • Septoria brown spot – Severity: 1

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