Date of Award
Master of Science (MS)
G. W. Tomanek
A portion of the mixed prairie was studied in an attempt to measure the effects of Japanese brome on production of native perennial grass. Vegetation was analyzed by paired foot-square quadrats. Japanese brome was removed from treated plots and control plots were left as they naturally occur. Microclimate study consisted of soil temperature and soil moisture under both treatments. Germination tests on Japanese brome were conducted in a Mangelsdorf germinator and early growth and development was studied with the use of phytometers in the greenhouse. Averages for a six-week period showed 20.90 and 18.18 percent soil moisture for treated and control plots, respectively, representing a statistically significant difference in soil moisture content. Highly significant differences in soil temperature existed between treated and control plots with averages of 22.4 and 20.70⁰ C., respectively. Production of Japanese brome averaged 1, 774 pounds per acre on March 1 but production decreased to an average of 957 pounds per acre by maturity (June 30). No statistical difference was found between the yield of perennial grasses from treated and control plots at maturity of Japanese brome (June 30) when the annual was removed from the treated plots on March 16. Production of perennial grasses at the end of the growing season (September 19) was significantly greater on the control plots than on treated plots with averages of 2,394 and 2,214 pounds per acre, respectively, when Japanese brome was removed from the treated plots on March 16. Removal of Japanese brome at maturity (June 30) had no effect on production of perennial grasses which averaged 2,385 and 2,394 pounds per acre for treated and control plots, respectively. Total yearly production on control plots (perennial grass plus Japanese brome) averaged 2,877 pounds per acre. Germination of Japanese brome caryopses averaged 94 percent. Freezing Japanese brome caryopses before germination had no effect on percentage germination, but non-frozen caryopses germinated approximately four hours sooner than frozen caryopses. Early growth and development of Japanese brome was observed from the Simple one-leaf two-root stage after four days of growth to the highly complex growth development 49 days after germination. The primary root penetrated to a depth of 81.0 cm. and the maximum depth of penetration of the 11 secondary roots was 77.5 cm. with a lateral spread of 15.0 cm. after seven weeks of growth. An average of 14 leaves per plant were found after seven weeks of growth.
Copyright 1962 Gale L. Wolters
Wolters, Gale L., "Competitive Effects of Japanese Brome (Bromus Japonicus Thunb.) on Native Perennial Grasses" (1962). Master's Theses. 764.