부산대학교 도서관

Economic and social pressures are spurring the study of alternate weed management strategies such as the development of competitive crop cultivars, capable of being used under an integrated management plan. The primary objective of this research was to determine whether western Canadian spring wheat (Triticum spp.) cultivars differ in their ability to compete against model weeds and whether those differences were expressed when challenged with wild weeds. A total of 71 wheat cultivars were grown in the absence or presence of simulated [cultivated oat (Avena sativa L.) and oriental mustard (Brassica juncea L.)] or natural [wild oat (Avena fatua L.)] weed competition conditions. Significant (p = 0.01) weed by cultivar interactions involving changes in yield cultivar rank were detected, indicating that the cultivars responded differently to competition. A small minority of cultivars such as Glenlea, CDC Rama, Genesis, AC Taber, AC Vista, Plenty, Napoleon, and BW652 had high-yield potential coupled with yield maintenance under weed pressure. The competitive ability advantage appeared to be associated with plant height or tillers per square meter as well as shorter vernalization requirement combined with photoperiod sensitivity. These outlier cultivar differences could be exploited in breeding new widely adapted varieties for scenarios where reduced herbicide weed control is desired, including situations where herbicide resistance limits chemical options. Cultivars with differing competitive ability under model weed conditions maintained their ranking when challenged by natural weed infestations. This suggests that selecting competitive spring wheat cultivars using a repeatable protocol based on model weeds is realistic. Key words: western Canadian spring wheat, weed control strategies, competitive ability, model weed system, Triticum aestivum L Sous l'efet des contraintes economiques et sociales, on envisage de nouvelles methodes pour combattre les mauvaises herbes, tel le developpement de cultivars competitifs, dont on pourrait se servir dans le cadre d'un programme de lutte integree. Les auteurs voulaient determiner si la capacite de concurrencer les plantes servant de modele aux adventices varie avec les cultivars de ble de printemps (Triticum spp.) utilises dans l'Ouest canadien et si ces variations s'expriment toujours quand le ble doit concurrencer les adventices sauvages. A cette fin, ils ont cultive 71 varietes de ble avec ou sans la concurrence de simulacres d'adventices [avoine (Avena sativa L.) et moutarde d'Inde (Brassica juncea L.)] ou d'adventices naturelles [folle avoine (Avena fatua L.)]. Les auteurs ont releve des interactions sensibles (p = 0,01) entre les mauvaises herbes et la culture, notamment une modification dans le classement de la variete d'apres son rendement, signe que les cultivars ne reagissent pas tous de la meme facon a la concurrence des mauvaises herbes. Bien que peu nombreuses, les varietes comme Glenlea, CDC Rama, Genesis, AC Taber, AC Vista, Plenty, Napoleon et BW652 combinent un rendement potentiel eleve et la stabilite du rendement sous la pression engendree par les adventices. Cet avantage semble lie a la hauteur du plant ou au nombre de talles par metre carre, de meme qu'a une vernalisation plus rapide, combinee a la sensibilite a la photoperiode. Ces cultivars d'exception pourraient servir a creer de nouvelles varietes mieux adaptees quand on souhaite reduire l'usage des herbicides ou que la tolerance aux herbicides restreint les possibilites sur le plan chimique. Les cultivars dont la competitivite differe lors de la modelisation conservent leur place au classement quand on les teste avec une population naturelle d'adventices. On en deduit qu'il serait realiste de selectionner des varietes de ble de printemps competitives en recourant a un protocole reproductible qui modelise les mauvaises herbes. [Traduit par la Redaction] Mots-cles : ble de printemps de l'Ouest canadien, methodes de lutte contre les adventices, competitivite, modelisation des mauvaises herbes, Triticum aestivum L.
Introduction The concept of sustainable agriculture is, in part, based on reducing inputs. Herbicides are the primary method of weed control in spring wheat and represent a major investment for [...]