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Industrial hemp (Cannabis sativa L.) has sparked renewed interest in western Canada in recent years, and there is very little research information available on its fertilizer requirements. The objective of this study was to determine the effect of surface-broadcast ammonium nitrate and seedrow placed monoammonium phosphate fertilizers on the production and seed quality attributes of industrial hemp (cv. Fasamo and Finola). Field experiments were conducted on a Black Chernozem silty loam soil at Melfort, Saskatchewan, Canada, in 2000, 2001 and 2002. Increasing N rates significantly increased plant height, biomass, seed yield and seed protein content of hemp in all years. Seed-applied P fertilizer increased plant height in all years, and biomass in 2000, but reduced plant density, biomass and seed yield in 2001 and 2002. Finola consistently had lower plant height, earlier maturity, heavier seeds, and higher seed yield, seed protein content and seed oil content than Fasamo. The average amount of nitrate-N in the 0–60 cm soil was 40 kg N ha-1. Seed yield kg-1 of N was 9.4, 5.9, 4.5 and 3.7 kg ha-1 for Fasamo, and 10.6, 7.7, 6.0 and 4.5 kg ha-1 for Finola, respectively, at 40, 80, 120 and 160 kg ha-1 of soil plus fertilizer N. Key words: Fertilizer, hemp, nitrogen, phosphorus, rainfall, soil extractable P, soil nitrate-N, cultivars

S fertilization on industrial hemp in Saskatchewan. Can. J. Plant Sci. 90: 179Á184. Industrial hemp (Cannabis sativa L.) has become a well-known crop in western Canada in recent years, but insufficient information is available on its nutrient requirements for optimum yield. Our objective was to confirm the response of two hemp cultivars to increasing levels of nitrogen (N), phosphorus (P) and sulphur (S) in various sites in the province of Saskatchewan, during 2006Á2008. Increasing N rates significantly increased plant height, biomass, and seed yield, when data were averaged across all sites (location-years), reaching maximum values at about 150 kg N ha(1 of applied N fertilizer. The cultivar Crag was taller and produced greater biomass than the cultivar Finola over all levels of N fertilizer rate. The minimum rate of N fertilizer to achieve maximum height/biomass for Crag, relative to Finola, was 5 kg N ha(1 lower for height (Finola: 163 kg N ha (1 ) but 9 kg N ha (1 higher for biomass (Finola: 180 kg N ha(1 ). Finola seed yield was more responsive to progressively greater rates of N fertilizer. Consequently, maximum seed yield (plateau) was 27% greater for Finola than for Crag, but 198 kg N ha(1 of fertilizer was required to achieve this maximum yield vs. 175 kg N ha(1 for Crag. There was generally little or no response to P fertilizer, on soils with adequate available P, or to S fertilizer on an S-deficient soil. Results from this study indicate that N fertilizer rate and cultivar choice are important management parameters to consider for industrial hemp production. Mots clé s: Engrais, cultivars du chanvre, azote, phosphore, soufre, P extractible du sol, N-nitrate du sol

. 2006. Seasonal biomass accumulation and nutrient uptake of wheat, barley and oat on a Black Chernozem soil in Saskatchewan. Can. J. Plant Sci. 86: 1005-1014. Dry matter and nutrient accumulation in the growing season are the main factors in the determination of seed yield and nutrient use efficiency. Field experiments were conducted with spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and oat (Avena sativa L.) in 1998 and 1999 at Melfort, Saskatchewan, Canada, to determine the biomass accumulation and plant nutrient uptake at different growth stages, and their relationship with days after emergence (DAE) and growing degree days (GDD). All crops generally followed a similar pattern of biomass and nutrient accumulation in the growing season, which increased continuously with growing time, with much faster increase at early growth stages than at late growth stages. Maximum biomass accumulation rate and amount usually occurred at late boot stage (46)(47) and ripening stage (89-90 DAE or 948-1050 GDD), respectively. Maximum rate of nutrient uptake occurred at tillering to stem elongation stages (22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36). Maximum amount of nutrient uptake generally occurred at the beginning of flowering to medium milk stages (61-75 DAE or 612-831 GDD), except for P in 1998 when it occurred at late milk to ripening stages (80-90 DAE or 922-1050 GDD). In general, the maximum nutrient uptake rate and amount, respectively, occurred earlier than maximum biomass accumulation rate and amount. For various cereal species/cultivars, maximum biomass accumulation rate was 204-232 kg ha -1 d -1 , and maximum uptake rate of N, P, K and S, respectively, was 3.2-5.7, 0.30-0.60, 3.85-7.05 and 0.45-0.60 kg ha -1 d -1 . The findings suggest that a sufficient supply of nutrients from soil and fertilizers at early growth stages is of great importance for optimum crop yield. -5,7, 0,30-0,60, 3,85-7,05 et 0,45-0,60 kg par hectare et par jour. Ces constatations laissent croire qu'un apport suffisant de nutriments par le sol et les engrais durant les premiers stades de croissance joue un rôle primordial dans un rendement optimal des cultures.

. 2007. Yield and quality of canola seed as affected by stage of maturity at swathing. Can. J. Plant Sci. 87: 13-26. Swathing is an important canola (Brassica napus L.) harvest operation in western Canada. The determination of the optimum timing for this operation is worth considering, as premature swathing may lead to reduced seed yield and quality. Seed yield and quality of three canola cultivars (44A89, AC Excel and Ebony), as affected by two seeding dates and several harvest times (six or eight swathing times and one direct combined treatment) was investigated on a Black Chernozem silty loam soil at Melfort, Saskatchewan, Canada, during 1998, 2000and 2001. Seed yield, weight, protein content (oil-free meal basis) and oil content generally increased with seed development and swathing time. Early seeding was more conducive to achieving higher seed yield, especially in good growing conditions, and resulted in heavier mature seeds with higher oil content. Seed oil composition also changed during seed development. The proportion of oleic (C18:1) and linolenic (C18:3) acids increased, while that of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0), linoleic (C18:2) and arachidic (C20:0) acids decreased. The levels of the long chain fatty acids eicosenoic (C20:1) and erucic (C22:1) acids were unaffected. However, the overall amount of fatty acids synthesized (mg 100 seeds -1 ) increased as seeds matured. Swathing was advantageous over direct combining in preventing weather-induced shattering. . En général, le rendement grainier, le poids, la teneur en protéines (tourteau délipidé) et celle en huile s'améliorent avec le degré de maturité de la graine et le moment où a lieu l'andainage. Des semis hâtifs favorisent un meilleur rendement grainier, surtout quand les conditions de croissance sont propices à cette culture, et donnent des graines plus lourdes et plus riches en huile à maturité. La composition de l'huile évolue également avec le développement de la graine. Ainsi, la proportion des acides oléique (C18:1) et linolénique (C18:3) augmente tandis que celle des acides myristique (C14:0), palmitique (C16:0), palmitoléique (C16:1), stéarique (C18:0), linoléique (C18:2) et arachidique (C20:0) diminue. La concentration des acides gras à chaîne longue comme les acides éicosénoïques (C20:1) et érucique (C22:1) n'est cependant pas affectée. La quantité globale d'acides gras synthétisés (mg par centaine de semences) augmente néanmoins avec la maturité des graines. L'andainage s'avère plus utile que la récolte directe pour prévenir l'égrenage prématuré attribuable aux intempéries.