Thèse de doctorat : Sciences Agronomiques : INPL : 2009. / Titre provenant de l'écran-titre.

Thèse de doctorat : Procédés biotechnologiques et alimentaires : Vandoeuvre-les-Nancy, INPL : 2005. / Titre provenant de l'écran-titre. Bibliogr.

Thèse (Ph. D.)--Université Laval, 2005. / Titre de l'écran-titre (visionné le 18 sept. 2007). Bibliogr.

Embora a expansão do cultivo da canola seja expressiva, no Sul do Brasil, poucos são os estudos envolvendo a fenologia e o crescimento das plantas, visando ampliar conhecimentos relativos à elaboração do rendimento de grãos, em resposta ao ambiente físico. Assim, este trabalho teve por objetivo avaliar a fenologia e o crescimento da canola, visando ajustar parâmetros bioclimáticos e avaliar respostas da cultura às variações do ambiente físico. Experimentos de campo foram conduzidos em 2009, 2010 e 2011, com diferentes genótipos de canola semeados de abril a julho, em delineamento de blocos ao acaso. Foram avaliadas as seguintes variáveis: datas dos principais estádios fenológicos, índice de área foliar, matéria seca de hastes, folhas, flores, síliquas e grãos, componentes e rendimento de grãos e parâmetros de interceptação de radiação fotossinteticamente ativa (RFA). A partir de dados meteorológicos, foram calculados balanços hídricos climatológicos e necessidade térmica da cultura (graus-dia), para cada ano e data de semeadura. A necessidade térmica variou durante o ciclo e subperíodos da cultura, em função de genótipos e datas de semeadura. A canola apresentou menor índice de área foliar quando semeada em abril e maio, porém, a longevidade do índice de área foliar foi maior do que em semeaduras de junho e julho. Hastes, flores e síliquas interceptaram a maior parte da radiação solar fotossinteticamente ativa após a ocorrência do máximo índice de área foliar. O coeficiente de extinção da cultura para RFA foi de 0,98. A eficiência de uso da radiação fotossinteticamente ativa variou de 1,9 a 2,8 g MJ-1, sendo mais elevada nos ambientes com baixos excessos hídricos, nos quais a cultura também expressou seus maiores rendimentos de grãos. O acúmulo de biomassa da parte aérea das plantas, ao longo do ciclo, não foi limitante à elaboração do rendimento de grãos. O híbrido Hyola 61 apresentou rendimento de grãos superior e mais estável, em diferentes ambientes, do que o Hyola 432. Semeaduras mais precoces, em abril e maio, apresentam maior potencial rendimento de grãos que as tardias, realizadas em junho e julho. / Although the expansion of rapeseed crops is expressive in Southern Brazil, there are few studies on phenology and growth of plants, aiming to amplify knowledge on the elaboration of the grain yield, in response to the physical environment. This study aimed to evaluate the phenology and growth of rapeseed plants, aiming to adjust bioclimatic parameters and to evaluate crop responses to variations in the physical environment. Field experiments were conducted in 2009, 2010 and 2011, with different genotypes of rapeseeds sown from April to July, in a randomized complete blocks design. The following variables were evaluated: dates of the main phenological stages, leaf area index, dry matter of stems, leaves, flowers, seedpods and grains, grain yield and its components, and interception parameters of photosynthetically active radiation (PAR). From daily meteorological data, climate water balances and thermal requirements of the crop (degree-days) were calculated, for each year and sowing date. The thermal requirements varied during the crop cycle and sub-periods for different genotypes and sowing dates. The lower leaf area index occurred when the crop was sown in April and May, but the longevity of the leaf area index was higher than in the latest sowing dates (June and July). Most of the incident photosynthetically active radiation was intercepted by stems, flowers and seedpods, after the occurrence of the maximum leaf area index. The extinction coefficient of the crop for RFA was 0.98. The use efficiency of photosynthetically active radiation ranged from 1.9 to 2.8 g MJ-1, being higher in environments with low water excesses, in which the crop also expressed the highest grain yields. The accumulation of aboveground biomass of plants, throughout the crop cycle, did not limit the grain yields. The hybrid Hyola 61 had higher and more stable grain yields than the Hyola 432, for different environments. The earliest sowing dates, in April and May, promoted the greatest grain yield, compared to the latest ones, held in June and July.

Embora a expansão do cultivo da canola seja expressiva, no Sul do Brasil, poucos são os estudos envolvendo a fenologia e o crescimento das plantas, visando ampliar conhecimentos relativos à elaboração do rendimento de grãos, em resposta ao ambiente físico. Assim, este trabalho teve por objetivo avaliar a fenologia e o crescimento da canola, visando ajustar parâmetros bioclimáticos e avaliar respostas da cultura às variações do ambiente físico. Experimentos de campo foram conduzidos em 2009, 2010 e 2011, com diferentes genótipos de canola semeados de abril a julho, em delineamento de blocos ao acaso. Foram avaliadas as seguintes variáveis: datas dos principais estádios fenológicos, índice de área foliar, matéria seca de hastes, folhas, flores, síliquas e grãos, componentes e rendimento de grãos e parâmetros de interceptação de radiação fotossinteticamente ativa (RFA). A partir de dados meteorológicos, foram calculados balanços hídricos climatológicos e necessidade térmica da cultura (graus-dia), para cada ano e data de semeadura. A necessidade térmica variou durante o ciclo e subperíodos da cultura, em função de genótipos e datas de semeadura. A canola apresentou menor índice de área foliar quando semeada em abril e maio, porém, a longevidade do índice de área foliar foi maior do que em semeaduras de junho e julho. Hastes, flores e síliquas interceptaram a maior parte da radiação solar fotossinteticamente ativa após a ocorrência do máximo índice de área foliar. O coeficiente de extinção da cultura para RFA foi de 0,98. A eficiência de uso da radiação fotossinteticamente ativa variou de 1,9 a 2,8 g MJ-1, sendo mais elevada nos ambientes com baixos excessos hídricos, nos quais a cultura também expressou seus maiores rendimentos de grãos. O acúmulo de biomassa da parte aérea das plantas, ao longo do ciclo, não foi limitante à elaboração do rendimento de grãos. O híbrido Hyola 61 apresentou rendimento de grãos superior e mais estável, em diferentes ambientes, do que o Hyola 432. Semeaduras mais precoces, em abril e maio, apresentam maior potencial rendimento de grãos que as tardias, realizadas em junho e julho. / Although the expansion of rapeseed crops is expressive in Southern Brazil, there are few studies on phenology and growth of plants, aiming to amplify knowledge on the elaboration of the grain yield, in response to the physical environment. This study aimed to evaluate the phenology and growth of rapeseed plants, aiming to adjust bioclimatic parameters and to evaluate crop responses to variations in the physical environment. Field experiments were conducted in 2009, 2010 and 2011, with different genotypes of rapeseeds sown from April to July, in a randomized complete blocks design. The following variables were evaluated: dates of the main phenological stages, leaf area index, dry matter of stems, leaves, flowers, seedpods and grains, grain yield and its components, and interception parameters of photosynthetically active radiation (PAR). From daily meteorological data, climate water balances and thermal requirements of the crop (degree-days) were calculated, for each year and sowing date. The thermal requirements varied during the crop cycle and sub-periods for different genotypes and sowing dates. The lower leaf area index occurred when the crop was sown in April and May, but the longevity of the leaf area index was higher than in the latest sowing dates (June and July). Most of the incident photosynthetically active radiation was intercepted by stems, flowers and seedpods, after the occurrence of the maximum leaf area index. The extinction coefficient of the crop for RFA was 0.98. The use efficiency of photosynthetically active radiation ranged from 1.9 to 2.8 g MJ-1, being higher in environments with low water excesses, in which the crop also expressed the highest grain yields. The accumulation of aboveground biomass of plants, throughout the crop cycle, did not limit the grain yields. The hybrid Hyola 61 had higher and more stable grain yields than the Hyola 432, for different environments. The earliest sowing dates, in April and May, promoted the greatest grain yield, compared to the latest ones, held in June and July.

Embora a expansão do cultivo da canola seja expressiva, no Sul do Brasil, poucos são os estudos envolvendo a fenologia e o crescimento das plantas, visando ampliar conhecimentos relativos à elaboração do rendimento de grãos, em resposta ao ambiente físico. Assim, este trabalho teve por objetivo avaliar a fenologia e o crescimento da canola, visando ajustar parâmetros bioclimáticos e avaliar respostas da cultura às variações do ambiente físico. Experimentos de campo foram conduzidos em 2009, 2010 e 2011, com diferentes genótipos de canola semeados de abril a julho, em delineamento de blocos ao acaso. Foram avaliadas as seguintes variáveis: datas dos principais estádios fenológicos, índice de área foliar, matéria seca de hastes, folhas, flores, síliquas e grãos, componentes e rendimento de grãos e parâmetros de interceptação de radiação fotossinteticamente ativa (RFA). A partir de dados meteorológicos, foram calculados balanços hídricos climatológicos e necessidade térmica da cultura (graus-dia), para cada ano e data de semeadura. A necessidade térmica variou durante o ciclo e subperíodos da cultura, em função de genótipos e datas de semeadura. A canola apresentou menor índice de área foliar quando semeada em abril e maio, porém, a longevidade do índice de área foliar foi maior do que em semeaduras de junho e julho. Hastes, flores e síliquas interceptaram a maior parte da radiação solar fotossinteticamente ativa após a ocorrência do máximo índice de área foliar. O coeficiente de extinção da cultura para RFA foi de 0,98. A eficiência de uso da radiação fotossinteticamente ativa variou de 1,9 a 2,8 g MJ-1, sendo mais elevada nos ambientes com baixos excessos hídricos, nos quais a cultura também expressou seus maiores rendimentos de grãos. O acúmulo de biomassa da parte aérea das plantas, ao longo do ciclo, não foi limitante à elaboração do rendimento de grãos. O híbrido Hyola 61 apresentou rendimento de grãos superior e mais estável, em diferentes ambientes, do que o Hyola 432. Semeaduras mais precoces, em abril e maio, apresentam maior potencial rendimento de grãos que as tardias, realizadas em junho e julho. / Although the expansion of rapeseed crops is expressive in Southern Brazil, there are few studies on phenology and growth of plants, aiming to amplify knowledge on the elaboration of the grain yield, in response to the physical environment. This study aimed to evaluate the phenology and growth of rapeseed plants, aiming to adjust bioclimatic parameters and to evaluate crop responses to variations in the physical environment. Field experiments were conducted in 2009, 2010 and 2011, with different genotypes of rapeseeds sown from April to July, in a randomized complete blocks design. The following variables were evaluated: dates of the main phenological stages, leaf area index, dry matter of stems, leaves, flowers, seedpods and grains, grain yield and its components, and interception parameters of photosynthetically active radiation (PAR). From daily meteorological data, climate water balances and thermal requirements of the crop (degree-days) were calculated, for each year and sowing date. The thermal requirements varied during the crop cycle and sub-periods for different genotypes and sowing dates. The lower leaf area index occurred when the crop was sown in April and May, but the longevity of the leaf area index was higher than in the latest sowing dates (June and July). Most of the incident photosynthetically active radiation was intercepted by stems, flowers and seedpods, after the occurrence of the maximum leaf area index. The extinction coefficient of the crop for RFA was 0.98. The use efficiency of photosynthetically active radiation ranged from 1.9 to 2.8 g MJ-1, being higher in environments with low water excesses, in which the crop also expressed the highest grain yields. The accumulation of aboveground biomass of plants, throughout the crop cycle, did not limit the grain yields. The hybrid Hyola 61 had higher and more stable grain yields than the Hyola 432, for different environments. The earliest sowing dates, in April and May, promoted the greatest grain yield, compared to the latest ones, held in June and July.

La croissance constante de la population mondiale exige l’élaboration de stratégies alimentaires capables de soutenir les besoins nutritionnels des populations. Parmi les moyens stratégiques mis en œuvre, nous pouvons citer l'utilisation des sous-produits de transformation des aliments pour des besoins nutritionnels humains. En ce sens, l’industrie de concassage des graines oléagineuses, produisant des huiles végétales, fournit des résidus qui sont riches en fibres et en protéines. Ceci fait de ces résidus d’excellentes matières premières pour le développement de nouveaux ingrédients pour l'industrie alimentaire. Le tourteau de canola est un sous-produit du processus de broyage des graines de canola. En 2007 par exemple, la production du tourteau de canola au Canada était de l’ordre de 2050 tonnes métriques. Sur base sèche, le tourteau de canola contient environ de 12 à 20% (p / p) de fibres et de 35 à 45% (p / p) de protéines. Sa composition en acides aminés est bien équilibrée, ce qui rend du tourteau de canola une source potentielle de protéines pour l'alimentation humaine. Toutefois, des niveaux élevés de facteurs antinutritionnels comme les glucosinolates et les phytates ainsi que la présence de composés phénoliques limitent l’utilisation du tourteau de canola dans des produits alimentaires. Les composés phénoliques dans le tourteau de canola sont responsables de la couleur foncée, du goût amer et de l’odeur désagréable des matrices alimentaires dans lesquelles le tourteau est utilisé. Le niveau de composés phénoliques dans le tourteau de canola est plus élevé que celui dans le tourteau de soja, et il doit être diminué avant d’utiliser le tourteau de canola comme source d'ingrédients alimentaires. La couleur du tourteau doit également être considérablement améliorée. Jusqu'à présent, il n'existe aucune technologie complètement réussie pour diminuer la teneur en composés phénoliques dans le tourteau de canola et améliorer son odeur, sa couleur et son goût. Dans le présent travail, nous avons développé une nouvelle approche pour améliorer l'utilisation du tourteau de canola et de ses dérivés (protéines et fibres) comme ingrédients dans des applications alimentaires humaines. Pour ce faire, le tourteau de canola a été décoloré (blanchi) par des solutions de peroxyde d'hydrogène. La couleur du tourteau a été considérablement améliorée et elle est passée de L * = 45 à L * = 78. Le traitement au peroxyde d'hydrogène a permis aussi l'amélioration de l'extractabilité de la matière sèche totale dans les solutions aqueuses. Cette extractabilité était d'environ 22% pour le tourteau initial, tandis que celle du tourteau traité avec du peroxyde d'hydrogène est de 83%. La solubilité élevée de la matière sèche totale, comprenant les protéines et les fibres, permettra d'améliorer la biodisponibilité de ces ingrédients. La teneur en polyphénols totaux a été abaissée d'au moins 93%. Aussi, la matière extraite à sec a été caractérisée par de très bons paramètres organoleptiques (couleur, odeur et goût). Nous espérons que ce travail contribuera à résoudre des problèmes nutritionnels à l’échelle mondiale. / This research work was aimed to study the possibility of enhancing the use of canola meal as a source of food ingredients. The main objectives of this research work were to discolour the meal and to evaluate the product properties as well as the effect of the treatment on the extractability of the total dry matter, protein profile, total polyphenolics content, and overall acceptability of the end product. The constant growth of world population requires governments in all countries to develop food policies to support the nutritional needs of populations. Among the strategic means adopted, we can found the use of by-products of food processing practices for human nutritional needs. In this context, vegetable oils crushing industry provides residues which are rich in fibres and proteins. This makes them excellent raw materials for the development of new ingredients for the food industry. Canola meal is a by-product of de-oiling process of canola seeds. For example, the production of canola meal in Canada in 2007 was estimated at 2050 metric tonnes. On a dry basis, canola meal contains approximately 12-20% (w/w) carbohydrates and 35-45% (w/w) proteins. The well balanced and favourable amino acid composition of the canola meal makes this latter a potential source of proteins for human nutrition. However, high levels of antinutritional factors such as glucosinolates and phytates and the presence of phenolics prevent canola meal from being fully used in food products. Phenolics in canola meal are responsible of the dark color of the food matrices in which they are used, bitter taste, and strong undesirable smell. The level of phenolics compounds in canola meal is at least an order of magnitude higher than in soybean meal, and has to be decreased before the meal can be used as a source of food ingredients. The meal color must also be significantly improved. Enhancing the overall quality of the canola meal would contribute to both higher nutritional and monetary values of this material. Until now, there is no completely successful large scale technology for decreasing the phenolic content in canola meal and for improving its color, bitterness, and strong smell. The prupose of the present work was to develop a novel approach to improve the use of canola meal and its derivatives (proteins and fibres) as ingredients in food applications. The canola meal was successfully discolored (bleached) following a treatment with hydrogen peroxide solutions. The meal color was significantly improved and passed from L* = 45 up to L* = 78. The treatment with hydrogen peroxide allowed enhancing the extractability of the total dry matter in aqueous solutions. The initial meal extractability was approximately 22% whereas the meal treated with hydrogen peroxide was characterized by an extractability of the total dry matter of 83%. The increased solubility of the total dry matter, including proteins and fibres, will enhance the bioavailability of these ingredients. Total phenolic content was lowered by at least 93%. The extracted dry matter was characterized by very good organoleptic parameters (color, smell, and taste). The output of this research work will hopefully contribute to solving nutritional problems worldwide.

Le canola (*Brassica napus* L.) est une culture avec des besoins élevés en azote. Les engrais verts de légumineuses sont une alternative moins polluante aux engrais azotés. L’objectif du projet était de déterminer l’effet d’un engrais vert intercalaire de trèfles rouge (*Trifolium pratense* L.) et blanc (*Trifolium repens* L.) sur le prélèvement en azote et le rendement d’une culture subséquente de canola, et comparer la réponse du canola à une fertilisation complémentaire minérale ou organique. Une expérience a été répétée deux fois (2013-2014, 2014-2015) à deux sites, selon un plan factoriel en tiroir, soit précédent cultural en parcelles principales (orge seul ou orge avec intercalaire de trèfles) et type de fertilisation (minérale (27-0-0) ou organique (lisier de porc)) et niveau d’azote disponible (0, 50, 100 ou 150 kg N ha⁻¹) en sous-parcelles. À l’enfouissement, l’engrais vert a apporté entre 28,3 et 150,5 kg N ha⁻¹. Aucune interaction n’a été observée entre l’engrais vert et le type de fertilisation. L’engrais vert n’a pas eu d’impact significatif sur le prélèvement en azote du canola, mais a augmenté le rendement pour un équivalent en azote minéral de 21,8 à 81,8 kg ha⁻¹. Dans les parcelles non fertilisées, les rendements ont augmenté de 6 à 42 %, l’effet s’estompant avec des doses d’azote croissantes. Le prélèvement en azote et le rendement étaient moins élevés avec le lisier qu’en fertilisation minérale, probablement en raison de pertes environnementales suivant l’application. Aucun maximum de rendement n’a été obtenu avec les doses croissantes de lisier, alors que des rendements maximaux ont été obtenus entre 120 et 150 kg N ha⁻¹ avec l’engrais minéral. En conclusion, l’engrais vert de trèfles a amélioré les rendements du canola, et la fertilisation minérale a entraîné de meilleurs rendements que le lisier, dont l’efficacité pourrait être améliorée par une meilleure gestion. / Canola (*Brassica napus* L.) is a crop with high nitrogen needs. Legume cover crops can serve as an organic nitrogen source and increase subsequent crop yield. The objective of this study was to measure the impact of a red (*Trifolium pratense* L.) and white clover (*Trifolium repens* L.) cover crop on canola nitrogen uptake and yield, and to compare canola response to mineral and organic fertilizers as supplemental nitrogen sources. A field experiment was repeated twice (2013-2014, 2014-2015) at two sites, in a factorial split-plot design with preceding crop (barley only or barley intercropped with clover) as main plots, and fertilizer type (mineral (27-0-0) or organic (pig slurry)) and nitrogen rates (0, 50, 100, and 150 kg N ha⁻¹) as sub-plots. At fall termination of cover crops, the clover provided 28.3 to 150.5 kg N ha⁻¹. No interaction was observed between cover crop and fertilizer type. Cover crops did not increase canola N uptake, but increased canola yields with a mineral fertilizer replacement value of 21.8 to 81.8 kg ha⁻¹. In unfertilized plots, cover crops increased yields from 6 to 42%, the gain decreasing as nitrogen application rate increased. Canola nitrogen uptake and yield were lower with pig slurry, compared to mineral fertilizer, possibly because nutrient losses occurred after slurry application. Moreover, crop yield did not reach a maximum value with increasing pig slurry rate, whereas a maximum yield was reached at 120 to 150 kg N ha⁻¹ with the mineral fertilizer. In conclusion, the clover cover crop improved canola yields and mineral fertilization resulted in higher canola yields compared to the organic fertilizer, whose efficiency could be improved through better management.

La lutte contre le Phoma du colza, causé par le champignon Leptosphaeria maculans, repose principalement sur la culture de variétés résistantes dont l'efficacité est peu durable. La reproduction sexuée confère un fort potentiel adaptatif au champignon confronté aux pressions de sélection exercées par les variétés résistantes : elle permet l'acquisition et l'association d'allèles de virulence, alors que les ascospores issues de la reproduction sexuée assurent la transmission de la maladie d'une saison culturale à la suivante. Nous faisons l'hypothèse qu'en début de contournement de résistance, la transmission de la virulence d'une génération à la suivante est limitée d'une part par la faible probabilité de reproduction sexuée entre isolats virulents et d'autre part par une dispersion des ascospores spatialement limitée. Pour tester cette hypothèse nous avons étudié (i) la dispersion des pycnidiospores par la pluie, (ii) la progression systémique du champignon dans la tige de colza et (iii) la structure spatiale des populations de L. maculans pour inférer les distances de dispersion des ascospores. Sous un générateur de gouttes en air calme, les pycnidiospores sont dispersées par les gouttelettes de pluie à moins de 40 cm de la macule source ; des résidus porteurs de pycnides peuvent causer des infections primaires de la maladie. Le succès de la phase systémique détecté par l'expression de nécroses au collet sur des plantules inoculées en conditions contrôlées augmente avec le nombre de points d'infection, mais diminue en présence de la résistance partielle ; la compétition entre individus peut limiter la présence concomitante des types sexuels au collet de la plante. Par conséquent, dans des champs avec des populations de L. maculans à faible densité, la dispersion des pycnidiospores par la pluie peut accroître la taille de la population pathogène et permettre la rencontre d'individus initialement distants, tandis que la progression systémique du champignon peut limiter la rencontre locale d'isolats virulents sexuellement compatibles. Pour 29 populations françaises génotypées à l'aide de marqueurs minisatellites, l'essentiel de la diversité génotypique est détectée à l'échelle d'une population (champ) ; l'absence de différenciation génétique entre populations distantes n'a pas permis de mettre en évidence une limitation des flux de gènes à l'échelle spatiale analysée. Ces résultats suggèrent que la dispersion du Phoma par les ascospores est beaucoup plus élevée que supposée et/ou que les tailles efficaces des populations du champignon dans une parcelle sont très grandes. Ces connaissances épidémiologiques devront être prises en compte pour améliorer les stratégies de déploiement durable des variétés résistantes.

Thèse de doctorat : Procédés biotechnologiques et alimentaires : INPL : 2006. / Titre provenant de l'écran-titre. Bibliogr.