Raynald Drapeau

Winter damage to perennial forage crops in eastern Canada : Causes, mitigation, and prediction

Harsh winter climate results in frequent losses of stands and yield reduction in many forage-growing areas of Canada and other parts of the world. Climatic conditions and crop management both affect the winter survival of perennial forage crops. In this review, we present the main causes of winter damage in eastern Canada and we discuss crop management practices that help mitigate the risks of losses. Predictive tools available to assess the risks of winter damage both spatially and temporally are also presented. Our understanding of the causes of winter damage and of the plant adaptation mechanisms to winter stresses, particularly the role of N and C organic reserves, has improved. Forage species commonly grown in eastern Canada differ in their tolerance to subfreezing temperatures and to anoxia caused by the presence of ice on fields. Some improvement in winter hardiness of forage legume species has been achieved through breeding in eastern Canada but new technologies based on laboratory freezing tests ...

Fusarium root and crown rot in alfalfa subjected to autumn harvests

Fusarium root and crown rot in alfalfa subjected to an autumn harvest was studied in plots established in the spring of 1996 or 1997, at three sites in Quebec. Autumn harvest treatments were started the year following establishment at each site. They were made at either 400, 500 or 600 growing degree-days (GDD; 5°C) after the last summer harvest. Samples were assessed for fusarium root and crown rot severity in autumn 1998 and spring 1999. Disease severity over all sites, cultivars, and sampling periods was ranked in the following order: 400 GDD > 500 GDD > 600 GDD > control (no fall harvest). Key words: Fusarium, root and crown rot, alfalfa, harvest management

Nutritive Value of Timothy Fertilized with Chloride or Chloride-Containing Liquid Swine Manure

Chloride fertilization of timothy (Phleum pratense L.) decreases forage dietary cation-anion difference to an acceptable value [(<250 mmol(c)/kg of dry matter (DM)] for dry dairy cows (Bos taurus). However, high Cl concentrations in forages as a result of fertilization might affect nutritive value. Two experiments were used to evaluate the effects of chloride fertilization on timothy spring growth and summer regrowth by determining concentrations of crude protein and neutral detergent fiber (NDF), in vitro true digestibility of DM (IVTD), and in vitro digestibility of NDF (dNDF). In an inorganic fertilization experiment, forages grown at 4 locations were fertilized with CaCl(2) (0, 80, 160, and 240 kg of Cl/ha per yr) or NH(4)Cl (160 kg of Cl/ha per yr) in combination with 2 N application rates (70 and 140 kg of N/ha per yr). The increase in Cl fertilization rate affected forage NDF concentration (+1.4%), IVTD (-0.8%), and dNDF (-1.2%) only at the highest rate of N fertilization, but this effect was not of biological importance. Crude protein concentration was not affected by Cl fertilization. Both Cl fertilizer types had a similar impact on forage nutritive value. In an organic fertilization experiment, forages grown at 2 locations received 1 of 7 experimental treatments [unfertilized control, inorganic fertilizer, raw liquid swine manure (LSM), and liquid fractions of 4 pretreated LSM types (decanted, filtered, anaerobically digested, and flocculated)] that provided, respectively, 0, 60, 41, 44, 44, 36, and 101 kg of Cl/ha per yr. The last 6 fertilizer treatments also provided 140 kg of N/ha per yr. The IVTD, dNDF, and concentration of NDF in timothy forage were not affected by the Cl content of the different LSM types. Nitrogen fertilization increased concentration of forage NDF and decreased IVTD and dNDF, but this effect was not biologically important. In both experiments, soil types and harvests had a negligible effect on forage nutritive value. Organic or inorganic Cl fertilizers applied to decrease timothy dietary cation-anion difference have little or no effect on forage nutritive value.

Yield, persistence, and nutritive value of autumn harvested tall fescue

Tall fescue, harvested or grazed in autumn, may be a potential source of forage but little is known of the effect of a fall harvest or grazing on yield and nutritive value of tall fescue in the mid-north of eastern Canada (˜ 1400 growing degree-days). Three tall fescue cultivars (Courtenay, Kokanee, and Montebello) were submitted to 10 harvest management treatments (two dates of second harvest and five dates of third harvest) over 3 production years in the Saguenay-Lac-St-Jean region (QC). The cultivars Courtenay and Kokanee were more productive and persistent than Montebello. The annual DM yield decreased by an average of 15% between the first and the second production year and by an average of 35% between the first and the third production year; these decreases were greater (22 and 41%, respectively) when the third harvest was taken in early October. Increasing from 28 to 35 d the interval between the first and second harvests increased DM yield of the second harvest by more than 0.5 Mg ha-1, but caused...

SHORT COMMUNICATION: Diurnal variations of nonstructural carbohydrates and nutritive value in timothy

Morin, C., Bélanger, G., Tremblay, G. F., Bertrand, A., Castonguay, Y., Drapeau, R., Michaud, R., Berthiaume, R. and Allard, G. 2012. Short Communication: Diurnal variations of nonstructural carbohydrates and nutritive value in timothy. Can. J. Plant Sci. 92: 883-887. Nonstructural carbohydrate (NSC) concentration in timothy (Phleum pratense L.) increased during the day by 16 to 41 g kg-1 DM (+23 to 137%) in spring and summer growth cycles and reached a maximum value between 12.8 and 13.2 h after sunrise in an area with 15 to 16 h of day length. This increase in NSC concentration was generally accompanied by a decrease in concentrations of neutral detergent fiber (-2 to 6%), acid detergent fiber (-1 to 7%), and N (-6 to 11%).

Rendement et valeur nutritive de la fétuque élevée cultivée en régions à faibles degrés-jours de croissance

in CP concentration was greater for the cultivar Courtenay. The mean concentrations of P, K, and Mg increased with increasing the number of harvests per year. The effect of three harvest managements on the concentration of water soluble sugars (SS) was limited and varied with the production year. The cultivar effect on ADF and SS concentrations was the same for the three harvest managements; the cultivar differences were significant but of small agronomic importance and they were limited to the third production year for ADF concentration and the second production year for SS concentration. Tall fescue, therefore, represents an interesting option for forage systems in agricultural areas characterized by an accumulation of around 1400 growing degree-days such as in the mid-north of Eastern Canada.