2017
Effect of Incremental Sub-Threshold Levels of Insect Defoliation on Yield of Soybeans in Mississippi
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Contributor/Checkoff:
Mississippi Soybean Promotion Board
Category:
Sustainable Production
Keywords:
Field management Soil healthTillage
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Angus Catchot, Mississippi State University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Mississippi Soybean Promotion Board
$71,858
Institution Funded:
Mississippi State University
$71,858
Brief Project Summary:

The focus of this project is to refine treatment recommendations by evaluating the effects of multiple defoliation events on soybean yield loss and how soybean planting date can further affect yield loss associated with defoliation of Mississippi soybeans.

Key Benefactors:
farmers, agronomists, extension agents

Information And Results
Project Deliverables

1. Both irrigated and non-irrigated locations did not yield lower than the check when defoliated 33 or 66%. Yield loss did occur, however, once defoliation levels reached 100% at V3 and V6 growth stages, and were independent of each other.
2. Continuous defoliation at any level throughout the vegetative stage did not reduce yields significantly below the untreated control. Defoliation levels of 66 and 100% at R3 reduced yields below the check. Defoliation levels of 33 and 66% occurring season-long reduced yields below the untreated check as well. These results indicate that defoliation occurring prior to the R3 growth stage has very little, if any, additional impact on reproductive defoliation yield losses.
3. The Starkville tests in 2015 and 2016 displayed trends that later-planted soybeans were more susceptible to yield loss from defoliation than earlier-planted beans. Soybeans planted mid-season suffered slightly less yield loss than the earliest and latest planting dates, with the exception of the mid-June planting date in 2016.

Final Project Results

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.