Pre- and post-vernalization ramet removal reduces flowering of red sorrel (Rumex acetosellaL.) in wild blueberry (Vaccinium angustifoliumAit.)

Abstract

. 2015. Pre-and post-vernalization ramet removal reduces flowering of red sorrel (Rumex acetosella L.) in wild blueberry (Vaccinium angustifolium Ait.). Can. J. Plant Sci. 95: 549Á556. Red sorrel is a common, ramet-producing herbaceous creeping perennial species in wild blueberry fields. Flowering and seed production occur primarily in overwintering ramets in Nova Scotia, Canada, and growers may therefore be able to adopt fairly simple management strategies to reduce or prevent flowering and seed production in this species. The objective of this research was to determine the effect of pre-and post-vernalization ramet removal on red sorrel flowering ramet density under both controlled and field conditions. Under controlled conditions in a growth facility, ramet populations were subject to pre-and post-vernalization clipping treatments to simulate late autumn and early spring ramet removal. Under field conditions, pre-and post-vernalization ramet removal was achieved using postemergence applications of paraquat applied at a rate of 1 100 g a.i. ha(1 in early autumn and spring. Under controlled conditions, pre-and post-vernalization ramet removal reduced the density of flowering ramets by 95% and significantly reduced the frequency of pots with flowering ramets. Autumn and spring applications of paraquat under field conditions significantly reduced the survival of overwintering ramets, resulting in a significant reduction in the density of flowering ramets. Pre-and post-vernalization ramet removal has the potential to be a component of an integrated weed management strategy for red sorrel in wild blueberry.Key words: Vernalization, ramet flowering, ramet removal, Rumex acetosella, Vaccinium angustifolium White, S. N., Boyd, N. S., Van Acker, R. C. et Swanton, C. J. 2015. La suppression des ramets avant et apre`s la vernalisation re´duit la floraison de la roselle (Rumex acetosella L.) chez le bleuet sauvage (Vaccinium angustifolium Ait.). Can. J. Plant Sci. 95: 549Á556. La roselle est une vivace trac¸ante a`ramets qu'on retrouve couramment dans les bleuetie`res. En Nouvelle-É cosse (Canada), la floraison de l'adventice et la production de graines surviennent principalement sur les ramets qui ont surve´cu a`l'hiver, si bien que les cultivateurs pourraient recourir a`des strate´gies de lutte assez simples pour empeˆcher le plus possible l'espe`ce de fleurir et de libe´rer ses semences. La recherche devait e´tablir les conse´quences du retrait des ramets de roselle avant ou apre`s leur vernalisation sur la densite´des ramets florife`res dans des conditions controˆle´es et au champ. Dans une installation de croissance aux conditions controˆle´es, les chercheurs ont coupe´les ramets avant et apre`s leur vernalisation afin de simuler leur e´limination a`la fin de l'automne et au de´but du printemps. Au champ, on a proce´de´a`une suppression manuelle des ramets avant et apre`s la vernalisation par l'application post-leve´e de paraquat a`une concentration de 1 100 g de matie`re active par hectare, au de´but de l'automne et...