Susceptibility of Gramineae to Gloeotinia Temulenta

Abstract

SUMMARYThe host range for Gloeotinia temulentais shown by natural and artificial inoculation to include numerous grasses. Severe infections were obtained in Agropyron spicatum, Agrostis palustris, A. tenuis, Elymus junceus, Festuca arundinacea, F. idahoensis, F. gigantea, F. myuros, F. ovina, F. rubra, Lolium multiflorum, L. perenne, L. remotum, L. temulentum, Poa amp/a, P. arachnifera, P. canbyi, P. compressa, P. juncifolia, P. nemoralis, P. nevadensis, P. pratensis, P. trivialis, and Secale cereale. Slight infections were noted on numerous other species. The only grass seed crops that have been damaged in Oregon are F. arundinacea, L. perenne, and L. temulentum. Serious infection is anticipated in F. rubra, Poa pratensis, and new, early-maturing varieties of L. multiflorum. Although susceptible, L. multiflorum and Agrostis spp. Now escape infection by late anthesis. Planting of L. temulentum was discontinued to aid in control in L. perenne. Apothecia were recovered from F. arundinacea, L. multiflorum, L. perenne, L. temulentum, and Poa ampla. Many susceptible species of Agropyron, Elymus, Festuca, and Poa are dryland grasses not planted in the disease-problem area of western Oregon. Apparently resistant grass crops include Alopecurus pratensis, Arrhenatherum elatius, Avena sativa, Bromus spp., Dactylis glomerata, Hordeum vulgare, Phalaris spp., Phleum pratense, and Triticum aestivum. Inhibition of apothecial formation above 20° C will probably restrict distribution of G. temulenta to areas with a cool, wet climate during anthesis of susceptible grasses. Excellent control of G. temulenta in the seed fields of the primary host plant, L. perenne, has greatly reduced exposure of other grass seed crops to natural inoculation.