Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Agronomy, Horticulture, and Plant Science

First Advisor

Adam Varenhorst


in-furrow, seeding rate, seed treatment, South Dakota, soybean, sunflower


Throughout the 2016 and 2017 growing season, field research experiments were replicated across South Dakota. Many times seed treatments are used prophylactic, which is neither good for the producers or the environment. Producers will be able to reduce production costs, if they only use a seed treatment when necessary. The purpose of the first experiment was to determine the effects of seed treatments in combination with planting date and seeding rate on soybean yield. To determine the effects, two years of field data from four eastern South Dakota locations were compared. Within each year and location we compared two planting dates (May vs. June), seven seeding rates (60,000, 80,000, 100,000, 120,000, 140,000, 160,000, and 180,000 seeds per acre), and three seed treatments (untreated control, fungicide only, and a fungicide+insecticide combination) with all treatment factor combinations replicated six times at each location. Stand count data was taken 14 days after soybean emergence. Yield data was collected from the middle two rows of each plot. The purpose of the second experiment was to determine the influence of commercial and experimental in-furrow insecticides as well as an insecticide seed treatment at two different rates on sunflower yield. This experiment was conducted at two locations near Volga, SD in the 2016 growing season. In 2017, this experiment was replicated once near Volga, SD and once near Highmore, SD. The in-furrow insecticides included Ethos XB, Capture LFR, Capture 3RIVE and Mustang Maxx. The seed treatment used was Cruiser 5FS at 0.25 and 0.375 mg per seed. These six different treatments were compared to an untreated control. All plots were replicated six times at each location. Stand counts were taken 14 days after emergence. Root injury feeding was collected 28 days after emergence. Yield data was collected from the middle two rows of each plot.

Library of Congress Subject Headings

Soybean -- South Dakota.
Sunflowers -- South Dakota.
Seed treatment.


Includes bibliographical references



Number of Pages



South Dakota State University



Rights Statement

In Copyright