Degree Type

Creative Component

Semester of Graduation

Fall 2018


Plant Pathology and Microbiology

First Major Professor

Gary Munkvold

Second Major Professor

David Dornbos

Third Major Professor

Anthony Townsend


Master of Science (MS)


Seed Technology and Business


Since the first Hybrid Rice Variety was released in the United States nearly twenty years ago, hybrids have become a favorite among rice producers in the South. Hybrid rice varieties offer increased yield potential, better disease resistance and herbicide traits that serve as solutions to weed and resistance issues for farmers and agronomists. As the popularity and demand for Hybrid rice has grown, so has the need for seed production, which often times has struggled to keep up with demand. This is due to multiple factors, including foundation seed avalibility, sterility issues and difficulty with cross-pollinating in field environments. In this experiment I explore the possibility of reducing the sterile female line seeding rate in attempts to lower foundation seed cost by having a pound of seed cover more area without reducing the F1 hybrid rice seed yield. Four experimental seeding rates were compared with our normal seeding rate of thirty pounds per acre (33.63 kilograms per hectare). Sterile female seed was planted in six plots, with each of the five seeding rates replicated three times per plot which equaled fifteen entries per plot for a total of ninety entries across the experiment. Two different planting dates were selected to serve as a planting date study and back up in the event unforseen damage affected the experiment. Two planting directions were also tested, east to west and north to south, in an effort to gauge any benefit of natural pollination received from the predominantly south wind during cross-pollination. Plots one, two, five and six, a total of sixty entries, were planted east to west over two planting dates. Plots one and two were planted first followed later by plots five and six. Plots three and four, thirty entries, were planted north to south and compared with plots 3 one and two which were planted the traditional east to west direction. Plots one thru four were all planted on the first planting date. A plot map can be seen in Figure 1 attached below. The experiment was maintained as if it were a commerical seed field. The seed yield average across all plots was 1171 pounds per acre (1312.52 kilograms per hectare) , with the highest yielding plot reaching 2430 pounds per acre (2723.67 kilograms per hectare) and the lowest yielding plot weighing 636 pounds to the acre (712.86 kilograms per hectare). Despite the large difference in individual plot yields, no one seeding rate was significantly different when averaged across the entire study. With all seeding rates averaging within 93 pounds (104.24 kilograms) from top to bottom the data would suggest there is no drag on yield incured by reducing the seeding rate. The data did show a response in planting direction as the east and west planted rows consistantly out yielded their north and south counterparts. Planting date data also show that the early plant date translated into better seed set in the fall. This information suggests that earlier seed field planting in an east-west orientation at lower female densities will improve hybrid rice seed production, which increase profibility for the seed producer.

Copyright Owner

Cody Brandl

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