Abstracts from Recent Publications
Kimberly D. Gwinn, Henry A. Fribourg, John
C. Waller, Arnold M. Saxon, and Marshall C. Smith. 1998. Changes
in Neotyphodium coenophialum Infestation Levels in Tall Fescue
Pastures Due to Different Grazing Pressures. Crop Science
38:201-204.
Based on the authors' knowledge, this is the first study that
documents a direct relationship between changes in endophyte
infestation level and grazing pressure. This research has
immediate implications for designing pasture management systems
that might include various stocking densities and tall fescues
of different endophyte infestation levels.
H. A. Fribourg, J. C. Waller, R. J.
Carlisle, R. J. M. Hay, L. R. Fletcher, H. S. Easton, and G. C.
M. Latch. 1997. Tall Fescue from Down Under. Tennessee Agri
Science 184:14-17.
Evaluation of two tall fescues, one with a novel endophyte, from
New Zealand grown at Ames Plantation during 1994-97 under normal
climatic condition, with good cultural and animal management and
at medium stocking densities led the authors to three primary
conclusions and/or observations:
1. These fescues are not well adapted in the southwesterly
portion of the tall fescue range in the United States.
2. The presence of the novel endophyte imparted some stress
tolerance to its host, resulting in measurably better, though
still thin, stands.
3. Novel endophytes, producing little ergovaline and hence
resulting in few detrimental effects on consuming herbivores,
may play an important role in escaping tall fescue toxicosis in
the future.
J. C. Waller, H. A. Fribourg, K. D. Gwinn,
and R. J. Carlisle. Effect of Grazing Pressure on Incidence of
Neotyphodium coenophialum in Tall Fescue Pastures. Poster
Presentation. American Society of Animal Science, July 29, 1998,
Denver, Colorado.
Based on research conducted at the Ames Plantation in west
Tennessee as part of a cooperative program between the Hobart
Ames Foundation and The University of Tennessee Agricultural
Experiments Station, the following graphic illustrates the
Results and Discussion section of the poster:
The authors provided the following
Conclusions as a result of these research findings:
Changes in E+ level have been ascribed by some to contamination
or environmental stress. We believe that grazing pressure and
neither environmental stress nor contamination were the primary
stresses and resulted in the changes in E+ levels for several
reasons:
1. changes occurred only in pastures with moderate or high
grazing pressures (GP); pastures with low GP did not change
significantly
2. there were no periods of extended drought and environmental
conditions did not differ among pastures
3. extreme precautions were taken to eliminate contamination of
E- pastures with E+ seed or rhizomes
4. although viable seed in animal feces can be a source of
significant contamination when animals are transferred from
pastures with high E+ levels to those with low E+, contamination
was eliminated by feeding animals a non-fescue forage for at
least 3 days prior to transfer to experimental pastures.