Soybean Sentinel Plot Report: September 13, 2022

Summary of reports:

We have only a few soybean reports this week as wet condition keep many extension educators out of fields. Insect and pathogen populations in soybean fields remain mild. Most fields soybeans have reached R5 or beyond when the economic threshold for insect defoliation is 30% defoliation across an entire field, so damage needs to be significant to justify an insecticide application that would require driving over the crop. Many fields have reached R6 or R7 and insects have little change to decrease yield at this point. For diseases, Septoria brown spot is common and white mold is present in some fields. Scout your fields to determine what is present and if populations are concerning for this year’s crop or future years, particularly for white mold. For information on implementing IPM in soybean fields, see our recently published fact sheet on the topic.

Background on the project

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 about 25 'typical' soybean fields in about 20 counties across the state, reporting the populations of plant pathogens and insect pests that they find. Our goal is to inform the agricultural community about 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").

Reports

13 September 2022 – Centre County – Adriana Murillo-Williams

Field between Bellefonte and State College

Growth stage: R6

• Bean leaf beetle – Severity: 1
• Grasshopper – Severity: 1
• Silver-spotted skipper caterpillar – Severity: 1
• Downy mildew – Severity: 1
• White mold – Severity: 1
• Stem canker – Severity: 1

12 September 2022 – Lancaster County – Jeff Graybill

Near Manheim

Growth stage: R7

• Septoria brown spot – Severity: 2
• No insect populations of note

12 September 2022 – Butler County – Justin Brackenrich

One field, north of Saxonburg

Growth stage: R7

• Grasshopper – Severity: 1
• Septoria brown spot – Severity: 2
• White mold – Severity: 1
• Frogeye leaf spot – Severity: 1

4 Sept 2022 – Potter County – Nicole Santangelo / Jack Thomas

Two fields, one near Ulysses, one south of Ellisburg

Growth stage: R7 (Ellisburg), Ulysses (R5)

• Japanese beetle – Severity: 1
• Green stink bug – Severity: 1
• Mexican bean beetle – Severity: 1 (Ellisburg)
• Septoria brown spot – Severity: 1
• Frogeye leaf spot – Severity: 1 (Ulysses)
• Deer damage present