Publication Date
1985
Location
Kyoto Japan
Description
The presence of a fungal endophyte (Acremonium coenophialum) in tall fescue (Festuca arondinacea) and high nitrogen (N) fertilizer input, has been associated with tall fescue toxicosis symptoms in beef cattle. Expression of toxicosis symptoms vary with season, however the dynamics of endophyte levels in a tall fescue over a growing season have not been described. Our study characterizes seasonal distribution of the endophyte in grazed fescue swards as influenced by cultivar and N fertilizer over two years (1983 and 1984). Three replicate 0.7 ha paddocks of 'Johnstons', 'Triumph' and 'KY-31' (low and high endophyte status; and 134 and 336 kg N·ha-1) were established in randomized block design. Plants were sampled at 4-week intervals, and fungal status ascertained microscopically. Endophyte was not present in Triumph and was greatest in KY-31 sown from a highly infected seed source. Endophyte levels increased in high endophyte KY-31 during the first year (P< 0.04) but remained relatively constant the second year (P=0.72). Endophyte levels in Johnstone and low endophyte status KY-31 were similar. Increased N fertilizer decreased fungal endophyte frequency KY-31. Expression of cultivar and N level impact upon endophyte status became more pronounced in the second year. Low endophyte status was generally, but not unequivocally associated with outstanding animal performance. Estimates of sample size for selecting sample numbers necessary to conduct valid assessment of endophyte status in the field, showed that ten tillers collected from each of four arbitrary zones in 0. 7 ha paddocks would be adequate.
Citation
Belesky, D P.; Devine, O J.; Wilkinson, S R.; Stuedemann, J A.; and Hildreth, D M., "Seasonal Distribution of a Fungal Endophyte in Tall Fescue Pastures" (1985). IGC Proceedings (1985-2023). 40.
(URL: https://uknowledge.uky.edu/igc/1985/ses11/40)
Included in
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Seasonal Distribution of a Fungal Endophyte in Tall Fescue Pastures
Kyoto Japan
The presence of a fungal endophyte (Acremonium coenophialum) in tall fescue (Festuca arondinacea) and high nitrogen (N) fertilizer input, has been associated with tall fescue toxicosis symptoms in beef cattle. Expression of toxicosis symptoms vary with season, however the dynamics of endophyte levels in a tall fescue over a growing season have not been described. Our study characterizes seasonal distribution of the endophyte in grazed fescue swards as influenced by cultivar and N fertilizer over two years (1983 and 1984). Three replicate 0.7 ha paddocks of 'Johnstons', 'Triumph' and 'KY-31' (low and high endophyte status; and 134 and 336 kg N·ha-1) were established in randomized block design. Plants were sampled at 4-week intervals, and fungal status ascertained microscopically. Endophyte was not present in Triumph and was greatest in KY-31 sown from a highly infected seed source. Endophyte levels increased in high endophyte KY-31 during the first year (P< 0.04) but remained relatively constant the second year (P=0.72). Endophyte levels in Johnstone and low endophyte status KY-31 were similar. Increased N fertilizer decreased fungal endophyte frequency KY-31. Expression of cultivar and N level impact upon endophyte status became more pronounced in the second year. Low endophyte status was generally, but not unequivocally associated with outstanding animal performance. Estimates of sample size for selecting sample numbers necessary to conduct valid assessment of endophyte status in the field, showed that ten tillers collected from each of four arbitrary zones in 0. 7 ha paddocks would be adequate.
