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A patch disease of turfgrass causing foliar lesions and patch symptoms on a Kentucky bluegrass (Poa pratensis L.) lawn in Edmonton, Alberta, and on creeping red fescue (Festuca rubra L. ssp. rubra) turf at Swift Current, Saskatchewan, is described. The symptoms are similar to those caused by Drechslera poae (Baudys) Shoem. and Cochliobolus sativus (Ito and Kuribay.) Drechsl. ex Dast., but the causal agent was identified as Ascochyta phleina Sprague, based on morphological and cultural characteristics. This fungal pathogen occurs on many grass and cereal species in North America, but has not been reported previously as the cause of a patch disease.

Hedysarum alpinum L. var. americanum Michx. (American hedysarum) is indigenous to parts of Saskatchewan. Plants grown from seeds collected at five locations in central Saskatchewan were transplanted into a nursery at Saskatoon, Saskatchewan and a study of the nutritive value of individual plants was undertaken to determine the potential value of American hedysarum as a forage legume for the northern Canadian prairies. Leaves and stems (analyzed separately) showed marked differences in chemical composition. However, they did not differ in the in vitro organic matter digestibility (OMD). American hedysarum plants had a much higher tannin content than alfalfa or birdsfoot trefoil plants grown at the same location. This may account for the relatively low OMD of this species. The protein and fiber fractions (of H. alpinum) compared favorably with those of alfalfa. Improvement by breeding for reduced tannin content would be necessary before American hedysarum would be acceptable as a forage crop.Key words: Hedysarum alpinum L. var. americanum Michx., American hedysarum, forage, tannin, in vitro digestibility, early growth

On genetical evidence Typhula FW, T. idahoensis Remsberg, and T. ishikariensis lmai should be considered as one species, and by priority the T. ishikariensis applied to it. Based on morphological characters the following taxonomic ranking is suggested: T. ishikariensis Imai var. ishikariensis, T. ishikariensis Imai var. idahoensis (Remsberg) comb.nov., T.ishikariensis Imai var. canadensis Smith & Årsvoll var.nov.Within this Typhula complex the latter two varieties differ most clearly morphologically, but are most closely related genetically. They are both found only in North America, while var. ishikariensis also occurs in Europe and Asia. Var. canadensis can be distinguished morphologically from the other two varieties by its smaller sclerotia and sporophores, by its more profuse production of aerial mycelium in culture, and the tendency of its sclerotia to be produced in bands, radial rows, and suspended in the aerial mycelium rather than in concentric rings. The only reasonably reliable way of separating the other two varieties is on sclerotial characters. Rind cells of var. idahoensis are more irregular in outline, with more lobate, occasionally digitate cells than var. ishikariensis.

(1981). Spring and summer brown patch of turfgrass caused by Rhizoctonia solani in western Canada. Canadian Journal of Plant Pathology: Vol. 3, No. 4, pp. 207-210.

Coprinus kubickae is reported from North America for the first time. The fungus was associated with a superficial fairy ring on turf of Agrostis stolonifera in Saskatchewan but proof of pathogenicity was not definite.

Didymella festucae (Weg.) Holm (imperfect state Phleospora idahoensis Sprague), endemic on native Festuca spp. in western North America and reported from a few arctic–alpine regions in Europe, is the cause of a major destructive stem eyespot disease in seed crops of red fescue, Festuca rubra L., in the Peace River region of northern Alberta and British Columbia. The original description of the disease as a leaf and pedicel blight requires modification because eyespots, staining, and later extensive blackening of culms and inflorescences are the common symptoms. The size range of ascospores, 18–63 × 4.5–14.0 microns (μ), and conidia, 18–105 × 3.0–9.0 μ, considerably exceeded dimensions previously given for D. festucae from Europe and P. idahoensis from North America and Europe. Although the morphology of fungal structures was highly variable, dimensions of ascospores and conidia from the Swiss type material fell into the size range established for North American material. Swiss type material of the perfect stage also yielded typical conidia of P. idahoensis. Microconidia are uncommon in natural material and cultures and their function is uncertain. Pathogenicity tests confirmed the wide natural-host range. Host immunity or physiologic specialization of the fungus is not indicated, but there is some evidence that isolates differ in degree of pathogenicity. For the present, P. idahoensis is suitably accommodated in Phleospora and D. festucae in Didymella, although both genera are ill-defined, requiring further study.

Collections of brome grass stubble at Saskatoon from March to July, 1970, yielded nine plant parasitic fungi: Leptosphaeria herpotrichoides De Notaris, L. luctuosa Niessl in Sacc., Ophiobolus herpotrichus (Fries) Sacc., Pyrenophora bromi (Died.) Drechsler, Myxormia atroviridis Berk. & Br., Hendersonia culmicola Sacc., H. crastophila Sacc., Septoria bromi Sacc., Stagonospora foliicola (Bres.) Bubak, as well as Pithomyces chartarum (Berk. & Curt.) M. B. Ellis, isolates of which may produce the hepatotoxin sporidesmin. Spore trappings of airborne spores yielded a much wider range of species including many saprophytes, some coprophiles, and parasites of plants other than brome. Thirty-eight airborne fungi are illustrated and identified.

Didymella proximella is reclescribed and illustrated from collections on Carex californien from Mary's Peak. Oregon. The Oregon specimens match the type of D. proximella from Finland. Ascostromata of D. proximella and pyenidia of a Stagonospora species were found on overwintered C. califomica in Oregon; ascospores yielded the same Stagonospora on agar. This species of Stagonosporc is morphologically distinct from Stagonospora stricta and the presence of ascostromata of D. proximella with pyenidia of S. stricta on the same lesions in the type of S. stricta is fortuitous.

A previously undescribed, sclerotial, low-temperature-tolerant fungus with orange sclerotia, is common on a wide range of plant species and substrates in Western Canada. It is often associated with snow mold complexes. It has also been found in eastern Canada and Norway, indicating a circumpolar distribution. It is described as Acremonium boreale n.sp. Some isolates were antagonistic towards common snow molds, viz. Fusarium nivale, Sclerotica borealis, Typhula ishikariensis var. ishikariensis and var. canadensis, and the nonsclerotial low-temperature basidiomycete in culture at low temperatures. Although it was weakly parasitic towards two grass species, its main ecological importance seems to be as an invasive primary saprophyte on a wide range of substrates. It may play a significant role in determining the nature and intensity of damage in snow mold complexes.

Relationships were sought between rainfall, grass rrumrnum temperature, trends in spore trap and green leaf spore counts of the facial eczema fungus, Pithomyces chartarum (Berk. & Curt.) M. B. Ellis and facial eczema liver damage in groups of test lambs admitted for three, 12, 24, 48, 96 hours or longer and in “day” and “night” grazers on paddocks prepared by weekly mowing. Groups of six test lambs, which had been fasted for 24 hours, were used to examine pasture toxicity through possible “danger periods”—when a rainfall of 12.7 mm (0.5 in.) was accompanied or followed by two or more days of grass minimum temperatures reaching or exceeding 12.8°c (55°F). The “indicator blip” in spore trap counts (as in previous seasons) was seen following a warm, wet period of weather in mid-December 1962. Although no liver damage occurred in test animals grazing at this time, it did occur at subsequent “danger periods” in January and February 1963. Pastures were highly toxic for two to four days at “danger periods” which...

In trials during the 1959–60 and 1960–1 seasons, counts of the spores of the fungus Pithomyces chartarum (Berk. & Curl.) M. B. Ellis were higher on short than on long pasture, and more liver damage occurred in lambs grazing the shorter herbage. No conclusions were reached on whether pre-treatments of the test areas, either by grazing or silage-making, affected the results. The results illustrate some of the difficulties in evaluating the effects of typical management practices, such as grazing or silage-making, as distinct from an atypical practice such as repeated gang-mowing, on the incidence and severity of facial eczema, particularly when weather and pasture conditions are unfavourable for outbreaks of the disease.

Mobile spore trap counts from fixed transects on pasture herbage showed diurnal periodicity of spores of Pithomyces chartarum (Berk. & Curt.) M. B. Ellis; this was related to the diurnal progression of atmospheric humidity in settled bright weather. In micro wind tunnel experiments, with cultures of the fungus on natural substrate, the lowest wind velocity employed (1 m/sec) detached few spores either at low or at high humidities. When the wind speed was increased to 2.7 m/sec and the air humidity reduced, increased numbers of spores were detached. In water-drop tower studies, it was shown that large drops of water impacting on spore-bearing material detached dry spores in large numbers. The observed rate of fall of single spores of the fungus in still air was close to the theoretical rate of fall of 0.845 cm/sec. Spores of P. chartarum already detached from litter would require only slight air turbulence to keep them airborne. It was shown that rain falling on dry, short pasture could detach and...

Material containing a high proportion of spores of Pithomyces chartarum was collected from grassland herbage by a suction cleaner technique. When dosed to sheep this material produced morphological changes in tissues identical to naturally-occurring asymptomatic cases of facial eczema and to similar cases produced by the oral administration of sporidesmin.

A description is given of the techniques for the collection and concentration of spores (conidia) of P. chartarum from grassland herbage, for chemical and biological assays for the toxin sporidesmin, which is implicated in facial eczema of sheep and cattle. A metal gauze and cotton wool filter system or a cyclone, both powered by an electric suction cleaner, are used for the collection of spores mixed with fine debris from herbage. The spores of P. chartarum are concentrated by rolling spores and debris on typing parchment to which the spores adhere, or by suction through fine nylon fabric with small glass cyclones; dry harvesting of spores grown on ryecorn is done with a cyclone. A wet spore harvesting technique is described. The field-cyclone technique may be used for “wet collection” from herbage for assessment of spore load when spore traps cannot operate and for collection of small insects and other fungi.

Occasionally a germinating spore of Pithomyces chartarum (Berk. & Curt.) M. B. Ellis has been noted on fresh green leaves of white clover and perennial ryegrass in aqueous mounts during spore counting. Germination is markedly favoured by aeration. Fragments of spores are intermittently seen on white clover leaves. These fragments appear to be the result of germination of the spores but no recognisable mycelium has been noted to be associated with them. Four collections of spores from pasture and from the C-isolate grown in culture showed high viability in laboratory germination experiments. At the optimum temperature (23–24°c) germination of the field spores commenced within ½ hr. Spores of the C-isolate were slower in starting to germinate. As suitable conditions of temperature and moisture for germination are likely to be presented to the spores on green leaves of herbage during summer and autumn it is questioned whether spores on leaves are viable. The fate of the spores on green leaves is imp...

A strip of short pasture herbage was successively spore-trapped and swept with suction equipment, and material bearing aleurospores of Pithomyces chartarum (Berk. & Curt.) M. B. Ellis collected. The numbers of these spores in the collected and purified material was determined by haemocytometer counts. It is deduced from the rapid decline in the number of spores collected and the decline in spore trap counts following the first collection that the mobile volumetric spore trap collects spores mainly from the litter substrate on which they are produced, and from which they can be readily detached, rather than from the green leafage where they adhere more firmly.

In 1960 and 1961 surveys were made on grassland herbage of paddocks in the Waikato region of New Zealand* with a mobile volumetric spore trap to determine the nature and magnitude of the fluctuations in estimated spore numbers of P. chartarum, the fungus implicated in facial eczema disease of sheep and cattle. The relation between these fluctuations and the weather conditions as recorded at a reference centre was examined. The trends in spore counts on the herbage of reference paddocks can give reliable indications of the trends in counts on paddocks in the surrounding farming district. The count levels at any one lime on different paddocks may vary considerably. Trends in estimated spore trap counts are markedly influenced by weather conditions. Major peak counts occurred in dry weather following moist warm conditions. Although estimated spore trap counts do not directly indicate spore load on grazed herbage, it is considered that the presence of a danger period for grazing animals is indicated ...

Cultural characters, spore morphology, and size indicated that a fungus consistently associated with culm and inflorescence lesions on the native fescues Festuca scabrella Torr., F. idahoensis Elmer, and F. ovina L. in Western Canada and northwestern United States was Phleospora idahoensis Sprague. The fungus was morphologically and culturally identical with P. idahoensis, which recently caused severe out-breaks of a stem eyespot disease in crops of the introduced creeping red fescue, F. rubra L. subsp. rubra, in northern Alberta and on the ‘Olds’ cultivar in central Alberta. The widespread occurrence of P. idahoensis in Western Canada and northwestern Great Plains suggests that it is endemic. The epidemiological implications for crops of introduced fescues of the occurrence of the pathogen on native species are considered.

The resistance of strains of northern, southern, and northern/southern hybrids of smooth bromegrass (Bromus inermis) to Pyrenophora bromi, the cause of a major leaf spot disease, was determined in field tests in northern Saskatchewan from 1967 to 1971. Infection derived from natural epidemics was supplemented with that from highly susceptible infector plants spaced in the test plots to improve uniformity of inoculum supply. No bromegrass strains were completely resistant to the pathogen. Four of the eight northern/southern cultivars and three of the five southern cultivars were more resistant to P. bromi than any of the nine northern types. The best southern cultivars, Baylor and Sac, were not significantly more resistant than the cult Magna and less resistant than the S-7382 and S-7306 strains, all of northern/southern-type. Basic clones of northern/southern-type strains, adapted to Western Canada, were superior in resistance to northern clones. Parental clones were more resistant than their progeny and this resistance declined from the Syn. 1 to the Syn. 2 in two northern/southern strains. Selection for resistance to the other major leaf spot pathogen, Selenophoma bromigena, resulted in a limited improvement also in resistance to P. bromi.

Transistorised electronic equipment is described which can be used for the continuous recording of changes in leaf wetness on living ryegrass (Lolium) leaves (using microclip electrodes) in pasture herbage in a semi-quantitative manner. It was designed for use in studies on spore dispersal and spore leaf loads of the facial eczema fungus Pithomyces chartarum (Berk. & Curt.) M. B. Ellis. The bridge, vibrator, and amplifier circuitry may also be used with non-living sensing elements in pastures.

Some of the deficiencies of spore trap and wash counts in the estimation of the spore load of Pithomyces chartarum (Berk. & Curt.) M. B. Ellis on herbage likely to be ingested by the grazing animal are considered. A technique for the sampling and microscopical counting of spores of the fungus on green leaves of white clover (Trifolium repens) and perennial ryegrass (Lolium perenne) is described. It can be used during wet weather when spore trapping is ineffective. It requires further development before it can be fully applied to field studies. In the examples cited, spore counts on white clover and rye grass showed similar trends within each of 3 paddocks; no regular relation appeared to exist between green leaf spore count and spore trap count during the sampling period.

In the epidemic years 1965 and 1966, field ratings confirmed that southern strains of smooth bromegrass, Bromus inermis Leyss, were generally less susceptible to leaf spot caused by Selenophoma bromigena (Sacc.) Sprague & A. G. Johnson than northern strains. The northern/southern hybrid S-6733, developed by mass selection and progeny testing, was found to resist S. bromigena at least as well as the southern strains Lincoln and Redpatch, and better than the southern Saratoga. It was found possible to improve resistance of the susceptible northern strain Carlton by mass selection. Northern strains probably do not have as great a potential for improvement in disease resistance as southern strains or hybrids.

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Dormie is a cultivar of Kentucky bluegrass (Poa pratensis L.) with a high field resistance to LTB snow mold. It is specially suited for use in amenity turf in the low snowfall areas of the prairie region.

The pyrenomycete Melanospora sphaerodermoides Grove is redescribed and illustrated from an abundant collection in a consignment of Seaside creeping bentgrass seed from Albany, Oregon, U.S.A.

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Pithomyces chartarum (Berk and Curt.) M. B. Ellis, the fungus associated with the disease known in New Zealand as ‘facial eczema’1, sporulates abundantly under suitable environmental conditions on litter in the pastures. The spores are found in large numbers on green leaves during periods when pastures are toxic to grazing animals. In this situation they may be ingested with the forage.