Sentinel Plot Program in Soybeans

This will be our last week of reporting. Insect and disease pest activity remains low in our plots. See below for the final reports.

After providing these reports weekly from mid-June until now, we have a great sense of the pest pressure in about 15 fields across Pennsylvania. The main conclusion I can draw is that insect and disease were low in our plots and rarely justified insecticide or fungicide applications. While these fields were selected to be representative of “typical” soybean fields in the state, we are certainly aware that many fields across Pennsylvania required insect or disease spray applications to protect yield from these pests. Nevertheless, to many peoples’ surprise the low pest populations in our soybean sentinel plots tends to by typical of our region; insect and disease populations requiring intervention are the exception not the rule. This tendency is the main reason why pest management specialists like myself stress scouting and economic thresholds so much. If there is no need to apply a treatment, why go through the effort and expense? Scouting is the key to determining whether an application will be necessary or useful.

We hope to run the sentinel plot program again in 2013. In the meantime, if you feel there are ways we could improve our new program, please contact me and let me know. Thanks to the county educators and staff that scouted the fields and thanks again to the Pennsylvania Soybean Promotion Board for supporting this effort.

Pests that were found during scouting are listed with their severity, which is rated on a 1-10 scale with 10 being the highest. Make sure you check your fields to determine your local populations, but these reports will give you a sense of what pests are active in fields. For all the reports thus far, see Penn State’s Field Crop Entomology website (http://ento.psu.edu/extension/field-crops-new).

Berks County – 17 Sept 2012

Field 1

Growth stage: R6.5

• Bean leaf beetle active – Severity: 1
• Potato leafhopper present – Severity: 1
• Grasshoppers active – Severity: 1
• Green cloverworm active – Severity: 1
• Lady beetles, damsel bugs and spiders active

York County – 14 Sept 2012

Growth stage: R6-7

• Grasshoppers active – Severity: 1
• Bean leaf beetle active – Severity: 1
• Anthracnose – Severity: 2
• Septoria leaf blight or bacterial leaf blight – Severity: 2
• Cercospora leaf blight – Severity: 2

Dauphin County – 10 Sept 2012

Growth stage: R7

• Silver-spotted skipper – Severity: 1
• Green cloverworm active – Severity: 1
• Brown marmorated stink bug – Severity: 2
• Grasshoppers – Severity: 3
• Green cloverworm – Severity: 1
• Lady beetles active