Crown Rust and Brown Blight Infection of Perennial Ryegrass Cultivars Representing Three Maturity Groups

Infection of perennial ryegrass with fungal pathogens was assessed during three years on a basis of a variety type. The scoring served a goal of searching for donor varieties for resistance breeding from amongst the most resistant variety types. Six types representing three maturity classes and two ploidy levels were compared. From amongst 33 cultivars, lates Barnhem (2x), Elgon (4x) and Herbie (2x) turned out to be most resistant against crown rust (1.8–1.9 pts). Brown blight proved to be the prevailing disease, which infected the least foliage (3.0–3.5 pts) in cv. Arvicola, Maurice (both 4x) and Aberdart (2x). Eight tetraploid cultivars preceded the most resistant diploid Herbie on the basis of combined resistance against the two fungi. Three healthiest tetraploids were late-maturing. Among the most resistant diploids four were late-maturing and one was intermediate. Direct effects of cultivars and years to the resistance against both diseases were highly significant (p 0.05) the brown blight resistance in tetraploid cultivars.