Effect of some factors on the incidence of choke (Epichloë typhina) in grass seed stands in the Czech Republic

Abstract

Cagaš B., Macháč R. (2012): Effect of some factors on the incidence of choke (Epichloë typhina) in grass seed stands in the Czech Republic. Plant Protect. Sci., 48: 10-16.Choke of grasses caused by Epichloë typhina occurred in 2008 and 2009 in more than 25% of grass seed stands of timothy (Phleum pratense and P. nodosum); a lower incidence was reported in orchard grass (Dactylis glomerata). A decline in disease incidence in 2010 was caused partly by a reduction in the total area of grasses grown for seed production and partly by a decrease of older grass seed stands. The incidence of choke in timothy varieties Odenwälder and Pampas was very high; they differed statistically from the other 24 grown cultivars. No difference was found among 21 varieties of orchard grass. The highest incidence of choke was observed in varieties Comer and Dolina (timothy) and Amera (orchard grass). The incidence of choke in cultivated varieties of Phleum spp. and D. glomerata was affected by stand age (the incidence of the disease in timothy was recorded in 13% of stands in the first cropping year and in 50% of stands in the fifth cropping year). Choke disease occurred in all regions where the species were grown for seed.

Incidence, Identification, and Mycoparasitic Activity of Clonostachys epichloë, a Hyperparasite of the Fungal Endophyte Epichloë typhina

“…The incidence of choke commonly reaches 30% in orchardgrass fields in France by the fourth year of seed production, making the stand unprofitable (Raynal 1991). Direct losses due to choke disease were estimated at more than $100,000 in the Czech Republic in 2008 (Cagaš and Macháč 2012). Previous attempts to control the spread of choke disease have not yielded the desired results.…”

Influence of the fungal hyperparasite Trichoderma harzianum on the growth of Epichloë typhina, an agent of choke disease in grasses

“…E. typhina is the only species of the genus Epichloë reported so far in connection with P. distance (unpublished). In the case of other grass species, significant economic losses occur as a result of Epichloë typhina in the yields of grasses used as feed in meadows-in Oregon, USA, losses due to choke disease were estimated at more than $820,000 per year (Pfender and Alderman 2006), whereas at more than $100,000 in the Czech Republic in 2008 (Cagaš and Macháč 2012).…”