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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #90439
Title: CLIPPING EFFECTS ON GROWTH DYNAMICS OF JAPANESE BROME

Author
item Haferkamp, Marshall
item KARL, M - FOREST SERVICE

Submitted to: Journal of Range Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Japanese brome has invaded many plant communities in the Northern Great Plains. Understanding how defoliation affects the life cycle of this species is critical for planning proper grazing management of communities infested with this annual. The objective of this study was to determine the effect of defoliation by clipping on growth of Japanese brome. Treatments included no clipping or clipping to a 3- or 6-inch stubble height weekly or biweekly for 65 to 70 days in a greenhouse. Separate studies were run in 1991, 1992, and 1997. Plants remained vegetative in 1991, and produced seed heads in 1992 and 1997. Clipping vegetative plants in 1991 reduced shoot numbers and leaf heights, whereas clipping plants with seedheads in 1992 and 1997 increased shoot numbers and reduced heights. Herbage accumulated during clipping, total herbage, and herbage + root production were similar in 1991 and 1997, but lower in 1992. The amount of herbage accumulated during clipping was reduced as we lowered stubble height from 6 inches to 3 inches on a biweekly frequency and as we increased the frequency of clipping from biweekly to weekly at either stubble height. However, lowering the stubble height reduced total herbage and herbage + root production. Increasing frequency of clipping did not generally affect production. Some seed heads were produced with the most severe treatment, suggesting plant control of Japanese brome would be difficult with defoliation.

Technical Abstract: Japanese brome (Bromus japonicus Thunb.) has invaded many northern mixed prairie communities. Understanding how defoliation affects the life cycle of this species is critical for proper grazing management of communities infested with this annual. The objective of this study was to determine the effect of defoliation on growth of Japanese brome. Treatments included no clipping or clipping to 75- or 150-mm stubble height weekly or biweekly for 65 to 70 days in a greenhouse. Response of Japanese brome tiller numbers, leaf height, and above- and below-ground biomass were measured in 1991, 1992, and 1997. Clipping vegetative plants in 1991 reduced tiller numbers and leaf heights, whereas clipping plants with reproductive shoots in 1992 and 1997 increased tiller numbers and reduced heights. Herbage accumulated during clipping, above- ground and total biomass were similar in 1991 and 1997, but lower in 1992. Accumulated herbage was reduced by reducing stubble height from 150 mm to 75 mm on a biweekly frequency and increasing the frequency of clipping from biweekly to weekly at either the 150 mm or 75 mm stubble height. However, reducing the stubble height reduced above-ground and total biomass. Increasing frequency of clipping did not generally affect biomass. Some inflorescences were produced with the most severe treatment, suggesting plant control of Japanese brome would be difficult with defoliation.