Y. A. Papadopoulos

Yield, herbage composition, and tillering of timothy cultivars under grazing

Timothy is widely grown for silage and hay in eastern Canada. The relative performance of timothy cultivars under grazing is not, however, well documented. This research determined dry matter production, herbage composition, and tiller characteristics of 34 timothy cultivars under two grazing schedules over 3 yr on the same plots. Several cultivars outyielded the standard cultivar, Farol (7.96 t ha-1), by up to 10% for the 3-yr mean. Richmond and Comtal were the highest-yielding cultivars (8.75 t ha-1) while AC Regal had the best relative yield persistence over the experimental period. Crude protein concentrations of cultivars ranged from 172 to 208 g kg-1 for early and 150 to 179 g kg-1 for late grazing. Neutral detergent fibre (NDF) concentrations ranged from 460 to 495 g kg-1 and concentration of acid detergent fibre (ADF) ranged from 241 to 270 g kg-1 among the cultivars in early grazing. Differences in NDF and ADF concentrations between early and late grazing schedules varied among the cultivars indi...

Ascophyllum nodosum Extract and Its Organic Fractions Stimulate Rhizobium Root Nodulation and Growth of Medicago sativa (Alfalfa)

The effects of the seaweed Ascophyllum nodosum extracts (ANE) on nitrogen (N)–fixing nodules and growth of alfalfa plants were studied under greenhouse conditions. The treatment of alfalfa roots increased the number of total nodules per plant with ANE (69%) and organic sub-fractions methanol (20%) and chloroform (35%) at 1 g L−1 concentration. The number of functional nodules was greater per plant in ANE (36%) and its organic sub-fraction chloroform (105%). Maximum increase in shoot length was observed in ANE-treated plants (42%) and chloroform-treated plants (42%). Root length was longer in the chloroform fraction (15%), whereas the shoot dry-weight accumulation was greater in plants treated with ANE (118%), methanol (85%), and chloroform (85%) than the control. Root dry-weight accumulation increased in plants treated with ANE (118%) and chloroform (69%) compared to the control. Further studies are under way to identify the chemical components in ANE and organic fractions.

Compositional changes over four years for binary mixtures of grass species grown with white clover

Kentucky bluegrass, meadow fescue, orchardgrass, tall fescue, timothy, and reed canarygrass were seeded in all possible two-grass combinations with white clover in conventional and underseeded barley treatments using a split-plot design at the Western Agriculture Centre near Pynn’s Brook, NL. The objectives were: (1) to assess dry matter yield (DMY) of two binary grass species when sown with white clover in mixtures under a system with cuttings at similar crop growth stages as rotational grazing and to assess the effect of underseeding to barley on this system; (2) to identify mixtures that enhance herbage distribution throughout the grazing season; and (3) to assess the sward dynamics over successive cropping seasons. The composition of the binary grass mixtures with white clover affected seasonal DMY, seasonal herbage distribution, and sward dynamics over the production years. Orchardgrass in mixtures decreased DMY, shifted the herbage distribution toward early season, and competed with other species. T...

Tapani red clover

Tapani is a 21-clone diploid synthetic cultivar of red clover (Trifolium pratense L.). It was developed by phenotypic selection at Agriculture and Agri-Food Canada, Crops and Livestock Research Centre, in Charlottetown, Prince Edward Island, and at the Soils and Crops Research and Development Centre in Quebec City, Quebec. The original material for this strain was selected from collections made in old stands of red clover in three Atlantic Provinces of Canada. Tapani is early flowering and winterhardy. In Atlantic Canada, Tapani yielded an average of 109% of the check cultivar Marino over three production years. This cultivar has superior re-growth potential with high second-cut herbage yield. Key words: Red clover, Trifolium pratense L., cultivar description

Harvest management affects yield and persistence of birdsfoot trefoil (Lotus corniculatus L.) in cool summer climates

Two studies determined the effect of birdsfoot trefoil harvest managements on persistence, productivity, and species composition under cool summer growing conditions. Single and double cut managements were harvested at 10, 50, and 100% bloom; triple cuts and simulated grazing were also evaluated. Double cut harvest management produced considerably more dry matter yield (DMY) in the first production year, but its advantage over single cuts in the second year depended on bloom at harvest. Harvesting at 10% bloom for single (and perhaps double) cuts appears to be the best system based on DMY, trefoil content, and stand density. Key words: Lotus corniculatus L., growth stage, stand density, simulated grazing, cool climate

Interactions between cultivars of legume species (Trifolium pratense L., Medicago sativa L.) and grasses (Phleum pratense L., Lolium perenne L.) under different nitrogen levels

Abstract: The transfer of nitrogen (N) from legumes to grasses is an important process in low-input forage production systems, and may be improved by selecting compatible species and cultivars. This study sought to examine what effect species and cultivar have on plant growth and N accumulation in temperate grass-legume mixtures under a range of nitrogen fertility levels. A pot study using two cultivars each of alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), perennial ryegrass (Lolium perenne L.), and timothy (Phleum pratense L.) in all grass-legume combinations was devised. Compatibility indices, based on plant performance grown in combination versus alone, were used to quantify the net impact legumes and grasses had on each other. The presence of legumes had an overall negative effect on the growth of grasses (87% compared with growing alone), but did improve tissue N content by weight and total accumulated N. Improvements in total N were highest in a single timothy cultivar (Champ; 169%), but highest net total N was achieved in a ryegrass cultivar (Bastion; 1.92 mg N). Results indicate that grass N accumulation in legume-grass mixtures may be influenced more by grass N demand than legume supply, which suggests that competition between grasses and legumes may be a major determinant of N transfer efficiency.

Evaluating the performance of alfalfa cultivars in rotationally grazed pastures

Although alfalfa (Medicago sativa L.) is an important and reliable hay crop in eastern Canada, it is generally not considered suitable for pastures. However, local studies have shown that alfalfa is capable of superior yield in mixtures under rotational grazing. This study evaluates the performance of commercially available, locally adapted, hay-type alfalfa cultivars and new experimental, grazing-type alfalfa synthetics under hay and two rotationally grazed regimes. Ten alfalfa cultivars, including five hay-type and five grazing-type cultivars, were seeded with the timothy (Phleum pratense L.) cultivar, Richmond, in mixtures. The two pasture regimes consisted of grazing to low and high residual heights. Over two dry growing seasons, the pasture management with high residual grazing height was more productive than the low; on average lenient rotational grazing pressure (high residual heights) produced 20% higher yield than low residual heights. Alfalfa cultivars selected specifically for continuous grazin...

AC Endure red clover

AC Endure red clover (Trifolium pratense L.) is a diploid cultivar of the double-cut type developed by mass selection at the Crop and Livestock Research Centre, Agriculture and Agri-Food Canada, Charlottetown, PEI. It is earlier flowering than Florex or Marino, and higher in forage yield, especially in the second and third harvest years. Key words: Red clover, Trifolium pratense L., cultivar description

AC Langille birdsfoot trefoil

AC Langille is a birdsfoot trefoil (Lotus corniculatus L.) cultivar developed by the Nappan Research Farm, Agriculture and Agri-Food Canada. It was developed through two cycles of mass selection for winterhardiness and one cycle of mass selection for seedling vigor. The original material was six distinct germplasms selected from the cultivar Leo and released from the Crop Science Department of the University of Guelph. AC Langille is superior to the check cultivar Leo in forage yield and seedling vigor in Atlantic Canada. Key words: Birdsfoot trefoil, Lotus corniculatus, cultivar description, seedling vigor

First report of Alternaria alternata causing leaf spot and blight symptoms on alfalfa in Canada

Abstract Severe blight and necrotic symptoms were observed on a 3-year-old alfalfa crop cultivar ‘Blue Jay’ at Indian Head, Saskatchewan during the summer of 2017. Symptoms appeared on blossoms, leaves and stems, and most of the infected plants were severely defoliated. The objective of this study was to isolate and identify the causal agent of the disease. Isolations from diseased alfalfa plants showing visible blight and necrotic symptoms collected from the infected field were made on potato dextrose agar (PDA). Morphological observations of the developing fungal colonies on PDA showed the presence of dark grey to dark green mycelium and conidia borne in chains with vertical and transverse septa, indicating the presence of the fungus Alternaria alternata. Molecular analysis of the ITS-5.8S region of rDNA (541 bp) and the TEF-1α gene region (606 bp) of the fungal isolates from alfalfa confirmed their identity as A. alternata. The pathogenicity of representative isolates was confirmed on alfalfa ‘Blue Jay’ and ‘Spredor 4’ plants in growth chamber tests. Necrotic and blight symptoms like those observed in the field appeared on leaves and stems followed by defoliation. To our knowledge, this is the first report of A. alternata causing a foliar disease on alfalfa in Canada.