Quantifying regrowth characteristics of bromegrass species (Bromus)in response to defoliation

Bromegrass species (Bromus) can produce high forage yields under the short growing season of western Canada and have excellent nutritive value. Smooth bromegrass (Bromus inermis Leyss.) and meadow bromegrass (Bromus riparius Rehm.) are the most commonly cultivated bromegrass species. Hybrid bromegrass (B. riparius X B. inermis) was developed in Canada by hybridizing smooth and meadow bromegrass. Regrowth potential differs among these three bromegrass species, but the morphological and physiological basis for these differences is unclear. Regrowth characteristics of three bromegrass species following defoliation to 5cm at the vegetative and stem elongation stages of growth were studied in the field and greenhouse. Above-and below-ground dry matter production, leaf area index (LAI) development, individual leaf area expansion, leaf-to-stem ratio, photosynthetic rate, tiller and axillary bud development, etiolated regrowth, and nitrogen concentration in stem bases were evaluated. Regrowth was similar among the three species when defoliated at the vegetative stage. Meadow bromegrass consistently produced more (P¡Ü0.05) above-and below-ground dry matter than smooth bromegrass following defoliation at the stem elongation stage, while that of hybrid bromegrass was generally intermediate to the other two species. Individual leaf photosynthetic rates did not differ among the three species. Individual leaf area expansion rate was faster (P¡Ü0.05) in smooth bromegrass than meadow and hybrid bromegrass. LAI of the three bromegrass species increased linearly with days of regrowth (r2¡Ý0.88, P¡Ü0.05), and the increase was greatest in meadow bromegrass, intermediate in hybrid bromegrass, and least in smooth bromegrass in all stages of defoliation. Similarly, the leaf-to-stem ratio was highest in meadow bromegrass, intermediate in hybrid bromegrass, and lowest in smooth bromegrass following all defoliations. Defoliation at the vegetative stage had no effect (P¡Ý0.05) on tiller development relative to the undefoliated treatment, whereas tiller development was negatively affected by defoliation at the stem elongation stage. After 60 days of regrowth, final tiller density was greatest in meadow bromegrass, intermediate in hybrid bromegrass, and least in smooth bromegrass in the field. A lower proportion of tillers in meadow bromegrass reached the reproductive stage compared to the other two species. The final tiller density following defoliation was similar among species in the greenhouse. Total buds tiller-1 and elongated buds tiller-1 were similar (P¡Ý0.05) among three species following defoliation at each growth stage; however, defoliation at stem elongation stage visually delayed bud development. Etiolated regrowth was greater in meadow and hybrid bromegrass (P¡Ü0.05) than smooth bromegrass 10 days after defoliation, but was similar thereafter. Concentration of N in stem bases was similar among species, but decreased with advancing maturity. Rapid regrowth of meadow bromegrass appears to be associated with more tillers, rapid remobilization of organic reserves during early regrowth, and allocation of more biomass to leaf tissue than to stems compared to the other two bromegrasses. Variation in regrowth among the species was not associated with expansion of individual leaf area, photosynthetic rates, total organic reserve remobilization, or nitrogen concentration in stem bases. Based on these characteristics, meadow bromegrass is the most suitable species for grazing, and smooth bromegrass the least suitable

Germination of two native wheatgrass (Agropyron) species under different temperature and water potential regimes

Non-Peer ReviewedNative wheatgrass species are important for land reclamation or rangeland re-seeding. The objective of this study was to evaluate seed germination of slender wheatgrass (Agropyron trachycaulum Link Malte) and northern wheatgrass (Agropyron asystachyum (Hook.) Scribn.) under different temperatures and water potentials. Over a 10 d period, germination was studied in four growth chambers with constant temperatures of 5, 10, 20 and 25°C and water potentials of –1.0, –0.8, –0.6, –0.4, –0.2 and 0.0 Mpa at each temperature. Two wheatgrass species showed a good germination at or higher than –0.4 Mpa water potentials when temperature was 20-25°C, but the percentage was reduced at or lower than –0.6 Mpa. Compared to northern wheatgrass, higher percent of seed germinated for slender wheatgrass at lower water potential, but slender wheatgrass required higher germination temperature

Evaluation of parent plants for alfalfa breeding

Non-Peer Reviewe

Relationship of morphological traits and seed yield of plain rough fescue grass (Festuca hallii (Vasey) Piper) with different origins

Non-Peer ReviewedSeed production in plains rough fescue (Festuca hallii (Vasey) Piper) is infrequent and unpredictable. The objective of this study was to compare seed yield of plain rough fescue collections and to determine correlation between phenotypic characteristics and seed yield. In 2006, a field nursery was established from 11 collections of plain rough fescue grass at the Semiarid Prairie Agricultural Research Centre near Swift Current (50°25' N, 107°44' W), Canada. Plot design was a randomized complete block design with three replications. Six phenotypic variables were measured in summer 2010. Seed yield varied among collection sites. Plant vigour rating (r=0.29, P<0.01) and number of reproductive tiller (r=0.47, P<0.01) were positively correlated to individual plant seed yield, while reproductive tiller height (r=-0.47, P<0.01) and crown width (r=0.62, P<0.01) were negatively correlated to seed yield. Individual plant biomass didn’t have any correlation with seed yield. Selecting vigorous individual plant with higher number of reproductive tillers may improve seed yield of rough fescue grass

Integrated management approaches for controlling lesser clover leaf weevils in red clover for seed production.

Non-Peer ReviewedSingle-cut red clover (Trifolium pratense L.) is an important forage seed crop in Western Canada due to its winter hardiness and economical value. However, infestation of lesser clover leaf weevil (LCLW) (Hypera nigrirostris F.) in red clover fields can lead to drastic yield losses (up to 80%). Moreover, limited data is available to support relationships of clover stand density and pest pressure. The aim of this research is to evaluate the effectiveness of different insecticidal materials in controlling LCLW and their impacts on the pollinator community, along with determining an optimal seeding rate for seed production. Four different insecticide methods Decis (Deltamethrin), Exirel (Cyantraniliprole), Voliam Xpress (Lambda-cyhalothrin & chlorantraniliprole) and untreated control, were compared for control of LCLW. Six different seeding rates (0.5, 2.5, 4.5, 6.5, 8.5, 10.5 kg/ha) are being compared for the b est seed yield over three years experiment. Pest pressure data on the LCLW in red clover fields was tracked over the 2018 and 2019 growing season in five locations, mostly in North Saskatchewan. Concentration of red clover fields and consequently red clover pests were greater in northern SK. The preliminary analysis suggests that both Decis, Exirel and Voliam Xpress can significantly reduce the LCLW larvae pressure in comparison with the control. All chemicals tend to suppress LCLW numbers from 1 to 6 days after treatment. In contrast, LCLW larvae numbers increase in 12 days after Exirel treatment whereas in Decis and Voliam Xpress the pressure remains constantly low. Rearing LCLW larvae on treated plants in lab conditions showed similar results in 10 days

A comparison study of alfalfa (Medicago sativa) populations with long-term grazing history

Non-Peer ReviewedUnderstanding the effect of long-term grazing on alfalfa populations is important for identifying superior alfalfa genotypes adapted to animal grazing. The objective of this study was to compare alfalfa populations collected from 14 ranch sites across four soil zones of Saskatchewan for dry matter at first and second cuts, stem number) plant height forage nutritive value (protein, fibers), and verticillium wilt resistance. Crude protein concentration was significantly different (P<0.001) among the populations, but fiber concentrations (acid detergent and neutral detergent fiber) were similar. Resistance (%) to verticillium wilt varied (P=0.0028) among the alfalfa populations. The initial results indicated that DM at first cut was significantly different (P<0.0001) among 14 alfalfa populations, with alfalfa population from MacDowell had the highest first cut DM (287.8g) and regrowth DM (121.7g). Among the four soil zones, alfalfa populations from Black Soil Zone had the highest DM (P<0.0001) at first cut than alfalfa populations from Brown, Dark Brown and Grey wooded soil zones. During regrowth, alfalfa populations from Black (99.7g) and Grey wooded soil zones (99g) had significantly (P<0.001) higher DM than those from Dark Brown (82.6g) and Brown (81.9g) zones. Also, plant height (PH) among 14 alfalfa populations was significantly different (P<0.0001), with plants in MacDowell being tallest (90.4 cm), and in Val Marie population being the shortest (67.3 cm). Furthermore, stem number at first cut was significantly different (P<0.0163), with MacDowell had the highest stem number (98 stem plant-1), and Val Marie had the lowest (68 stem plant-1). There were positive correlations between DM yield with plant height at first cut (R=0.68, P<0.0001) regrowth DM with stem number (R=0.76, P<0.0001). In conclusion, alfalfa populations from these long-term grazing sites had diverse for the measured traits in this study, which may be useful for further selection for grazing tolerance and regional adaptation

Mixed Species Seeding: A Means to Increase Production in Temperate Pastures

Seeding mixed species for forage production has been suggested as a means of increasing productivity and stabilizing yields under a changing climate. Forages have traditionally been sown as monocultures or binary mixtures only, with the emphasis being on species and not necessarily their function or compatibility. While natural plant communities typically may be dominated by a single species, they are comprised of several species and function-al groups. This paper provides the results of sowing multiple species at semiarid sites within the North American Great Plains and identifies a similar result from a more humid region reported within the literature

Promising native forage options for semi-arid prairies of western Canada

Non-Peer ReviewedThere is growing interest in native plant species for their use as forage, pasture, energy crop, and as land reclamation and revegetation materials. This article reports the results of population improvement work on northern wheatgrass (NWG), purple prairie clover (PPC), white prairie clover (WPC) and plains rough fescue (PRF) carried out at Swift Current Research and Development Centre - Agriculture and Agri-Food Canada. Substantial selection differential were achieved in all species in terms of growth vigour, plant health, biomass and seed yield in all species. This suggests ample scope for selection gain for the desirable traits. Seed shattering is one of the challenges facing the domestication and commercialization of these native plant species

Evaluation of Forage Yield and Quality of Low-Lignin Alfalfa in Monoculture and Binary Mixtures in the Dark Brown Soil Zone of Saskatchewan

Non-Peer ReviewedThe objective of this study was to compare low-lignin Hi-Gest® 360 alfalfa to a conventional legume in both monoculture and binary mixtures. Two varieties of alfalfa (monoculture) [Medicago sativa L. cv. AC Grazeland (Grazeland) and Hi-Gest 360 (Hi-Gest] or in mixture (binary) with AC Success hybrid bromegrass (HB) (Grazeland+HB and Hi-Gest+HB) were grown at a Dark Brown soil zone site (52o07′ N, 106o 38′ W) in Saskatchewan and harvested at 3 maturity stages (stage) of alfalfa [1 = 10% bloom; 2 = 40% bloom; and 3 = 100% bloom)] over 2 yr. Forage was harvested on June 21, June 25, and June 29 2018, and July 8, July 12, and July 16 2019. All plots were established in a randomized complete block design with four replications using forages as treatments. Plot size was 6.2 m × 1.2 m (7.44 m2) with 4 rows and total of 48 plots. Dry matter yield (DMY; 2-yr) and nutritive value (1-yr) of forages were determined. Results indicate that monoculture Hi-Gest alfalfa had greater (P 0.05) for forage quantity and quality. However, forages at maturity stage 3 had greater DMY (1058 vs. 783 kg), but lower CP (17.6 vs. 19.6%) and IVNDFD48 (37.1 vs. 42.3%) than those at maturity stage 1. The sugar content of forages linearly increased (P 0.05) observed between AC Grazeland+HB and Hi-Gest+HB mixtures for DMY or quality profiles. Monoculture had greater CP (18.5 vs. 12.0 %), ADFCP (2.5 vs. 1.5%), lignin (6.9 vs. 4.7%), fat (3.0 vs. 2.6%), RFV (174.8 vs. 91.8), NEm (1.6 vs. 1.3 Mcal/kg), NEg (0.96 vs. 0.77 Mcal/kg), but lower DMY (920 vs. 3343 kg/ha), ADF (27.4 vs. 35.9%), NDF (36.3 vs. 61.9%), starch (0.41 vs. 0.82%), and IVNDFD48 (39.2 vs. 50.7%), compared to binary mixtures. Results suggest that Hi-Gest alfalfa as a monoculture yielded less than AC Grazeland, however Hi-Gest monoculture had higher nutritive value than AC Grazeland, but was similar for yield and quality in mixture, suggesting Hi-Gest 360 alfalfa is a viable alternative legume for Dark Brown soil zone of Saskatchewan