Semester of Graduation

Fall 2021

Degree

Master of Science (MS)

Department

SPESS

Document Type

Thesis

Abstract

Field studies evaluated the influence of planting date, maturity group, and harvest timing on soybean yield and seed quality at the LSU AgCenter Northeast (NERS), Macon Ridge, and Dean Lee Research Stations in 2018-2020. In addition, the influence of harvest aid and fungicide application on seed quality impact from delayed harvest and environment was investigated at NERS in 2019 and 2020 in both field and environmentally controlled growth chambers. Soybean yield was maximized when maturity group IV and V soybean varieties were planted between Mid-April and Mid-May. Earlier and later planting dates did not result in maximized yield. Planting date impacts on seed quality, however, were negligible. Soybean varieties within maturity group 4.5 to 5.3 can result in acceptable seed quality and maximized yield in Louisiana, assuming plants are harvested at the optimum harvest timing (when seed reach 13% moisture) and not delayed 14 to 28 days. At NERS, harvest aid application had no impact on soybean seed quality impacts from delayed harvest and saturated (100% relative humidity) environment. Delaying harvest beyond approximately 20 days in the field past optimum harvest timing can result in reduced seed quality. In addition, seedpod exposure to high relative humidity conditions (100%) for as little as 48 hours after optimum harvest timing can result in poor seed quality. At NERS, fungicide application had no impact on seed quality impacts from delayed harvest and saturated environment in the absence of disease pressure. Delaying harvest beyond 20 days in the field past optimum harvest timing or 4 days in a completely saturated environment can result in significant seed quality reduction.

Committee Chair

Donnie Miller

DOI

10.31390/gradschool_theses.5430

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