Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Plant Science


South Dakota is located on the northern edge of the grain sorghum belt, a location which presents unique problems to sorghum seed producers in this area. The seed producer must consider many factors when t deciding where to locate a prospective seed field. High on this list of factors are weather risks such as drought, hail, high humidity, low temperature, and frost damage to see. Information on physiological maturity of a crop is very important to a seed producer. A common definition of this term is . . . that point at which maximum dry weight of grain or seed is first reached. Physiological maturity can be measured by the seed quality characteristics of test weight or 1,000 kernel weight. A seed producer must expand the limits of this definition to include yield (seed quality plus quantity) the seeds' and morphological maturity as manifest by germination and moisture percentage. Combined, this information provides valuable information in regard to harvest guidelines for seed purposes. Physiological maturity of grain sorghum has been reported to occur between 23 percent and 39 percent moisture. This variability is largely the result of varietal and seasonal variations. Because of this, maturity information of major varieties produced in a specific climatic area should be helpful to a seed producer in that area. Specifically, a sorghum seed producer in the northern grain sorghum belt must know the earliest possible stage he can harvest quality seed to escape the environmental risks to which sorghum is subjected in September and October. This study was undertaken to determine the earliest stage at which quality seed can be harvested from common male sterile parents grown on the northern edge of the grain sorghum belt. Information presented on yield, kernel weight, test weight, percent moisture, arid germination as related to harvest date should be useful to prospective seed producers in South Dakota.

Library of Congress Subject Headings




South Dakota State University Theses



Number of Pages



South Dakota State University