Jing, Q., Be´langer, G., Qian, B. and Baron, V. 2014. Timothy yield and nutritive value with a three-harvest system under the projected future climate in Canada. Can. J. Plant Sci. 94: 213Á222. Timothy (Phleum pratense L.) is harvested twice annually in Canada but with projected climate change, an additional harvest may be possible. Our objective was to evaluate the impact on timothy dry matter (DM) yield and key nutritive value attributes of shifting from a two-to a three-harvest system under projected future climate conditions at 10 sites across Canada. Future climate scenarios were generated with a stochastic weather generator (AAFC-WG) using two global climate models under the forcing of two Intergovernmental Panel on Climate Change emission scenarios and, then, used by the CATIMO (Canadian Timothy Model) grass model to simulate DM yield and key nutritive value attributes. Under future climate scenarios (2040Á2069), the additional harvest and the resulting three-harvest system are expected to increase annual DM yield ('0.46 to '2.47 Mg DM ha (1 ) compared with a two-harvest system across Canada but the yield increment will on average be greater in eastern Canada (1.88 Mg DM ha (1 ) and Agassiz (2.02 Mg DM ha (1 ) than in the prairie provinces of Canada (0.84 Mg DM ha (1 ). The DM yield of the first harvest in a threeharvest system is expected to be less than in the two-harvest system, while that of the second harvest would be greater. Decreases in average neutral detergent fibre (NDF) concentration ((19 g kg (1 DM) and digestibility (dNDF, (5 g kg (1 NDF) are also expected with the three-harvest system under future conditions. Our results indicate that timothy will take advantage of projected climate change, through taking a third harvest, thereby increasing annual DM production.Jing, Q., Be´langer, G., Qian, B. et Baron, V. 2014. Rendement et valeur nutritive de la fle´ole re´colte´e trois fois dans le futur re´gime climatique du Canada. Can. J. Plant Sci. 94: 213Á222. On re´colte la fle´ole (Phleum pratense L.) deux fois par anne´e au Canada, mais avec le changement climatique pre´vu, une troisie`me coupe pourrait s'ajouter aux deux premie`res. Les auteurs voulaient e´valuer les conse´quences du passage d'un re´gime de deux a`trois re´coltes dans les conditions climatiques pre´vues a`dix endroits du Canada sur le rendement en matie`re se`che (MS) de cette culture et sur les principaux parame`tres de sa valeur nutritive. Les sce´narios sur le climat futur ont e´te´cre´e´s graˆce a`un ge´ne´rateur stochastique de conditions me´te´orologiques (AAFC-WG), a`partir de deux mode`les du climat mondial fonde´s sur deux taux d'e´missions hypothe´tiques du GIEC. Ensuite, les auteurs ont applique´ces sce´narios au mode`le CATIMO (Canadian Timothy Model) sur la culture des gramine´es afin de simuler le rendement en MS et les principaux parame`tres de la valeur nutritive de la fle´ole. Selon les sce´narios sur le futur climat (2040Á2069), la re´colte supple´mentaire et le re´gime a`trois coupes devraient augmenter le ren...

Jing, Q. and Bélanger, G. 2012. Short Communication:Yield trend analysis of an ageing timothy sward using a modelling approach. Can. J. Plant Sci. 92: 1263–1266. Observed and simulated potential dry matter (DM) yields of the timothy (Phleum pratense L.) primary growth were compared to disentangle the yield trend from the effect of year-to-year climatic variations in an ageing sward (1 to 7 yr). Observed DM yields were close to simulated potential DM yields in the first 4 yr, but they were around 60% of simulated potential DM yields in the last 3 yr. This confirms that variations in air temperature and/or solar radiation could not explain the lower DM yield observed in the last three production years.