Barrett's esophagus: endoscopic diagnosis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87018/1/j.1749-6632.2011.06045.x.pd

Influence of resistant cultivars and crop intervals on clubroot of canola

Clubroot, caused by Plasmodiophora brassicae, is an important constraint on canola (Brassica napus) production in Canada. Rotations of clubroot-resistant (CR) canola cultivars in various sequences, and planting intervals between canola with non-host crops and fallow periods, were evaluated to determine their effects on clubroot severity and P. brassicae resting spore populations under field and micro-plot conditions. Under micro-plot conditions, the rotation sequences including CR canola, continuous fallow and the non-host barley reduced gall weight by 63-100% and clubroot severity by 34-100% compared with continuous planting of susceptible canola. No visible clubroot symptoms developed following continuous fallow or the non-host crop. Under field conditions, clubroot severity was very high (78% ID) in the continuous susceptible canola sequence. Most of the CR canola rotation sequences significantly reduced clubroot severity by 12-23%, but continuous fallow, continuous barley, and alternating the CR canola cultivars ‘45H29’ or ‘73-47’ with ‘TC72429-10’ reduced clubroot severity t by 32-36%. A comparison of intervals between canola crops, four cropping sequences, (continuous susceptible canola, alternating canola with barley or pea, a 2-year non-host interval between canola crops, and a 3-year non-host interval between canola crops), was conducted over 5 years. A 2- or 3-year non-host interval improved plant height, plant biomass and seed yield, and reduced gall mass, P. brassicae propagules in the soil and clubroot severity. A significant yield increase of more than 3600% was observed in a 3-year non-host interval.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author