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Creeping bentgrass (Agrostis stolonifera L.) is a high-value turfgrass species that offers opportunities for western Canadian seed companies and producers. The objective of this study was to evaluate creeping bentgrass seed yield and the relationship between seedhead density and seed yield across a diverse range of cultivars. A series of four trials was established in Manitoba between 1992 and 1994 and included 18th Green, Cobra, Emerald, National, Penneagle, Pennlinks, Putter, Southshore, UM86-01 and UM86-02. Seed production and seedhead density were measured for 2–3 yr at each location. Additional yield component measurements included harvest index and thousand seed weight. The three cultivars developed within the region consistently showed high seed yield, seedhead density and harvest index and were numerically ranked in the top four for seed yield across all 11 location years. UM86-01 was in the highest grouping for seed yield across all harvests with yields ranging from 312 to 582 kg ha-1. Seedhead density was strongly related to seed yield (highly significant in five of six comparisons) and therefore has the potential to be a valuable indicator of relative seed yield in creeping bentgrass. These results indicate that creeping bentgrass seed yield is variable across cultivars and that seedhead density can serve as a good predictor of seed production potential across cultivars. Key words: creeping bentgrass, harvest index, seedhead density, seed yield, yield components.

The continuing development of adapted alfalfa (Medicago sativa L.) cultivars that combine high yield, disease resistance, winterhardiness, and grazing tolerance is of great value to the beef cattle industry in western Canada. This study evaluated alternative management strategies and plant measurements for assessing the grazing tolerance of alfalfa cultivars over 3 yr. Seven hay-type, four pasture-type, and one dual-purpose (hay or graze) cultivars were established in pure stands and in mixture with meadow bromegrass (Bromus riparius Rehm. syn.B. biebersteinii Roem & Schult). Stands were defoliated under continuous or rotational stocking with beef cattle (Bos taurus). Plants we reassessed for winterhardiness, percent alfalfa within row, percent alfalfa cover, basal area and species composition. Continuous stocking resulted in consistent and significant differences between cultivars, whether persistence was measured as percent alfalfa within row, percent cover and basal area, in both pure and mixed stands (P < 0.05). High correlations between measurement techniques (r = 0.74 to 0.99; P < 0.05) confirmed the value of alfalfa within row and alfalfa cover as time and labour efficient methods to evaluate grazing persistence. Competition between alfalfa and meadow bromegrass resulted in a significant confounding effect under rotational stocking (P < 0.05). Winter injury was identified as an important criteria to evaluate for grazing persistence. The most grazing-tolerant genotypes were selected for subsequent breeding efforts to combine winterhardiness, grazing tolerance, and high productivity. This research showed that grazing method, grass competition, and severe winter conditions strongly influence differential survival of alfalfa cultivars under grazing in western Canada. Key words: Alfalfa, grazing tolerance, grazing systems, Medicago sativa L., Medicago falcata L. Arcang, persistence

Single-year hay alfalfas (Medicago sativa L.), berseem (Trifolium alexandrinum L.) and red clovers (Trifolium pratense L.), chickling vetch (Lathyrus sativus L.) and lentil (Lens culinaris Medik.) were evaluated for rotational yield and N benefits to the following first-year wheat (Triticum aestivum L.) and second-year barley (Hordeum vulgare L.) crops. Field experiments were initiated in 1997 and 1998 on a Riverdale silty clay soil at Winnipeg, Manitoba. Yield and N content of the following wheat crop were increased following legumes compared to wheat following a canola control. Wheat yield and N content averaged 2955 kg ha–1 and 76.1 kg ha–1, respectively, following the chickling vetch and lentil, 2456 kg ha–1 and 56.4 kg ha–1 following single-year hay legumes, compared with 1706 kg ha–1 and 37.9 kg ha–1 following canola. Non-dormant alfalfas (dormancy rating of eight or greater) contributed to larger grain yields than the dormant alfalfas only in the first year of each experiment. The chickling vetch and lentil provided similar or higher subsequent crop yields and N content for 2 yr compared to a canola control or fallow treatment. This study shows that some increase in yield can be achieved by using a single-year alfalfa hay crop instead of fallow; however, exclusive green manuring of chickling vetch and lentil crops can produce the most increase in yield and N uptake in subsequent crops. Key words: Alfalfa (single-year), legumes (annual), green manure, nitrogen, cropping system

Alfalfa (Medicago sativa L.) cultivar development programs routinely incorporate resistance to fungal diseases that limit forage yield, quality and stand longevity. "Hay molding", caused by saprophytic fungi, reduces forage quality during the post-harvest period, but genetic resistance has not been reported. The objective was to determine the response to selection for post-harvest fungal resistance in alfalfa. Initially, 1144 genotypes from 22 alfalfa cultivars were screened for post-harvest fungal resistance with a combination of Aspergillus species. Forty resistant and 40 susceptible genotypes were selected by measuring percentage of leaf area with fungal coverage. The selected genotypes and their maternally derived half-sib families were screened for resistance to Aspergillus repens. Mean leaf area with fungal coverage was significantly (P

Plant breeders have long sought to improve grazing tolerance of alfalfa without sacrificing the beneficial yield and quality attributes of this species. Most efforts have focussed on selecting for traits (e.g., creeping rootedness) related to grazing tolerance and/or simulated grazing, but these efforts failed to account for the multiple stresses caused by grazing animals. Trait selection often led to sacrifices in yield and other desirable characteristics resulting in cultivars that were not robust across grazing management systems and environments. An innovative selection procedure was recently developed at the University of Georgia which incorporated intensive grazing with continuous stocking by beef cattle. The development of "Alfagraze" using this procedure showed that grazing tolerance and high yields can be incorporated into the same cultivar, along with consistent performance across grazing management systems and environments. Subsequent research has shown that grazing tolerance can be improved within elite, high-yielding, multiple-pest-resistant cultivars and breeding populations. Selection using intensive grazing with continuous stocking has been summarised in a "Standard Test Protocol" that is now being successfully used by public and private alfalfa breeders and in cultivar evaluation programs in the USA, Canada, and other countries. Key words: Medicago sativa, Medicago sativa ssp. falcata, persistence, lucerne, grazing tolerance, Alfagraze

Forage deterioration due to field and storage fungi represents a major economic loss for hay producers. A series of experiments was conducted to develop a methodology for screening alfalfa plants for resistance to post-harvest fungal colonization. Pure cultures of Aspergillus glaucus, Aspergillus repens, Aspergillus flavus, Aspergillus versicolor and Aspergillus fumigatus, isolated from alfalfa forage sampled during field wilting and storage, were established and maintained to produce a 105 spore mL−1 suspension containing an equal proportion of spores from each Aspergillus spp. Alfalfa leaves were dipped in concentrations of propionic acid solution to simulate levels of resistance to fungal activity. Fully-developed trifoliate leaves were placed adaxial side down onto petri plates containing a dichloran (2 mg mL−1) and glycerol (18% vol/vol) agar. The Aspergillus spp. spore suspension was sprayed onto each petri plate and the plates were incubated under dark conditions at 25 °C and 70% relative humidity. Plates were monitored daily for percent of leaf area colonized. The random screening of a small population of cloned alfalfa genotypes using this screening procedure indicated that variation in post-harvest resistance to fungal attack does exist for greenhouse and field-grown plants harvested at an early vegetative stage. Leaf dry matter was not related to genotype variation in post-harvest susceptibility to fungal colonization; however, leaf soluble carbohydrate level was negatively correlated (P

Alfalfa seed weight and number of seeds per pod are important characteristics which have been associated with seed yield and seed quality. The objective of this research was to investigate the relative influence of seed and pollen parents and temperature during pollination on individual seed weight and number of seeds per pod. The relative influence of seed position in the pod on seed weight was also investigated. Twelve diverse clones were designated as seed (4) and pollen (8) parents. They were grown in the greenhouse at 24/18 day/night temperature and then transferred to growth chambers which were maintained at either 18 or 27 °C during and 24 h after pollination. Seed weight and number of seeds per pod were influenced by temperature during pollination, and also by both seed and pollen parents. The position of the seed in the pod influenced seed weight. The largest seed occurred at the base of the pod, which may have resulted from a differential nutrient supply from the base to the top of the pod. The number of seeds per pod was greatest at 27 °C. This was attributed to enhanced pollen fertility and fertilization success at the higher temperature. Both seed and pollen parents influenced seed weight and number of seeds per pod, and there were significant seed × pollen parent interactions for both traits. Environmental influence and pod position effects on seed weight and number of seeds per pod were small when compared with genetic effects. Selection for seed characteristics in seed and pollen parents could improve alfalfa seed production and seed quality. Key words: Alfalfa, Medicago sativa L., seed weight, number of seeds, temperature during pollination

Shoot morphological characteristics are important determinants of turf quality in creeping bentgrass. The objectives of this research were to determine differences for tiller and stolon characteristics among creeping bentgrass cultivars and germplasms and compare these characteristics between seedlings and established turf. Two experiments involving 10 and 15 entries were grown in controlled environment chambers and harvested as seedlings at 21, 35 and 49 d and 21, 28 and 35 d, respectively. Nine and fifteen creeping bentgrass entries were grown in separate field experiments on sand-based golf greens and core samples were taken for subsequent measurements at 3 yr and 1 yr, respectively. Tiller and stolon measurements included seedling tillers plant−1 in the controlled environment; tillers m−2 on established turf; and leaf number, leaf width, plant height/stolon length, internode length, internode number, and stolon diameter in all experiments. The correlation coefficient for seedling tillers plant−1 at 35 d between the two controlled environment experiments was r = 0.835 and for tiller density between the two field experiments was r = 0.930. There were differences among the creeping bentgrass entries for tiller number (9 7 to 20.2) and internode length (20 to 54 mm) when measured at 35 d and for tiller density (67 to 227 × 103 m−2) in established turf. Correlation coefficients between seedling tillers plant−1 at 35 d and tiller number m−2 in established turf ranged from r = 0 701 to r = 0 826. There was also a high correlation for stolon internode length between seedling and established turf, with r values ranging from r = 0 725 to r = 0.948. These results document differences for tiller and stolon characteristics between creeping bentgrass cultivars and germplasms and indicate the potential for plant improvement of these characteristics in creeping bentgrass using 35-d-old seedlings in a controlled environment. Key words: Creeping bentgrass, tiller number, tiller density, stolons, turf, seedling

Timothy (Phleum pratense L.) is a bunch-type cool season perennial grass species grown in Manitoba primarily for seed production. The objectives of this study were to determine the effect of post-harvest residue management (straw removal-SR, straw and stubble removal-SSR and fall burning-Burn) on tiller production, yield components and seed yield of five timothy cultivars (Basho, Climax, Goliath, Hokuo and Salvo), and to better understand the association between yield components and final seed yield in timothy crops grown in the dry subhumid region of the Canadian prairies. Two experiments were conducted over four production seasons at Arborg, MB and one production season at St. Claude, MB. Tiller number per m2 in spring (TS) and at harvest (THV) were measured in 1990 at St. Claude and in 1990 and 1991 at Arborg. Residue management (RM) treatment ranking for TS was Burn −2 at harvest was also unaffected by RM. Seed yield was unaffected by RM in all instances, except at Arborg in 1989 where a significant RM × cultivar interaction was observed. The basis of the interaction was the greater sensitivity of Hokuo to the Burn treatment. Cultivar differences for seed yield were relatively consistent over years and between the two experiments, with Climax always ranking in the high yielding group and Salvo with the low yielding group. Based on analysis of yield components, it appeared that RM most affected early season growth (i.e. TS), while cultivar most affected later season growth (fertile tillers per unit area, seed yield per fertile tiller (SYFT)). Seed yield differences were most closely associated with SYFT (r2 = 0.97**) across cultivar treatments. Key words: Burning, straw removal, harvest index, yield components, forages

Biska is a creeping bentgrass cultivar (Agrostis palustris Huds.) selected for increased tiller density, dark green colour and seed yield. In comparison with other bentgrasses, Biska has shown higher tiller densities and higher seed yields under Manitoba conditions.Key words: Cultivar description, creeping bentgrass, Agrostis palustris Huds.