Page 177 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

yields decreased by 42.8 % and 35.7 %, respectively, with a pH increase ranging from 5.5 to 7.5. In the
strips with the canola-wheat rotation, lime increased canola yields by 2.6 %; however, it did not affect
wheat. Oat and wheat yields were reduced by 5.6 % and 2.8 % after liming in strips with the oat-wheat
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rotation. Crop yields showed a strong to moderate relationship (R =0.42 to 0.67) with pH and SOM. This
research indicates that pH and SOM play a significant role in improving crop productivity and, hence,
should be monitored in crop fields to develop better site-specific recommendations.
Keywords: Liming, soil pH, crop yield, crop sequences, spatial variability

*[O144] THE EFFECT OF INTEGRATED CROP MANAGEMENT PRACTICES ON WEED GROWTH
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AND PERSISTENCE TRAITS. Uthpala Ekanayake , Rob Gulden , Chris Willenborg , Jonathan Rosset ,
and Dilshan Benaragama . Department of Plant Science, Faculty of Agricultural and Food Sciences,
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University of Manitoba,66 Dafoe Road, Winnipeg, MB, R3T 2N2, Canada; and Department of Plant
Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, S7N 5A8,
Canada
Correspondence to: dilshan.benaragama@umanitoba.ca

The potential of Integrated Crop Management (ICM) via combining fertilizer management and cultural
weed management has been understudied, yet understanding the impact of ICM on weed growth and
persistence is crucial for managing herbicide resistance. In 2023, a four-way factorial field experiment
was established as split-block design with four replicates at the Carman research field, Manitoba to
evaluate the impact of ICM on weed growth and weed seed germination traits in a spring wheat (Triticum
aestivum L.). The treatments were; fertilizer application timing (spring, fall), placement (broadcast,
banding), rate (50%, 100%), and weed management (IWM, standard). Integrated Weed Management
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included narrow row spacing (6"), high crop density (400 plants m ), and early seeding while the standard
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weed management was 12” row spacing, 200 plants m crop density, and late seeding. Weed emergence
and growth were monitored within designated quadrants in each plot. Weed seeds collected in two
cohorts (populations with similar emergence timing) were subjected to germination tests. Crop and weed
management practices interactively influenced crop growth, thus increasing competition on weeds. The
combination of half-rate with standard weed management had 23% greater crop biomass than half-rate
and IWM. Weed density was significantly affected by the interaction of fertilizer timing and weed
management where the combination of fall application and IWM had a 75% lower density compared to
spring with standard weed management. Wild oat (Avena fatua L.) heights at maturity were influenced by
fertilizer rate and weed management interaction, with a 39% increase observed in the half-rate with
standard compared to full-rate with IWM. Similarly, the interaction of fertilizer rate, timing, and weed
management significantly impacted redroot pigweed (Amaranthus retroflexusL.) heights, showing a 41%
increase under banding, full-rate, and standard compared to broadcasting, full, and IWM. Weed biomass
was 89% lower in the combination of fall application with IWM, than spring with standard. The germination
of wild oats from the first emerged cohort was significantly influenced by all treatments. Fall application
increased germination by 6% compared to spring-banding by 5% compared to broadcasting, half rate by
10% compared to full; and IWM by 9% over standard. The second cohort also showed significant
responses, with banding and half-rate leading to 5% and 8% higher germination rates, respectively.
Redroot pigweed responded positively to the half-rate, showing an 8% increase in germination. These
preliminary findings suggest a complex interplay between fertilizer and weed management on crop-weed
growth and weed seed persistence.

[O145] THE EFFECT OF BORON ON CLUBROOT SEVERITY AND DEFENSE MECHANISMS IN
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BRASSICA NAPUS. A. Sedaghatkish , S. Chesney , B. D. Gossen , and M. R. McDonald . Department
of Plant Agriculture, University of Guelph, Guelph, ON, N1G 2W1, Canada; and Saskatoon Research
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and Development Centre, Agriculture and Agri-Food Canada, Saskatoon, SK, S7N 0X2 Canada
Correspondence to: asedagha@uoguelph.ca

Clubroot, caused by Plasmodiophora brassicae Wor., is an important disease of canola (Brassica napus
L.) and other Brassica crops worldwide. This soil-borne Chromist pathogen causes the formation of
‘clubbed’ roots that disrupt nutrient uptake and result in severe yield loss. Resting spores of the pathogen
are long-lived and the rapid emergence of resistance-breaking pathotypes make sustainable
management strategies crucial. Application of boron (B) to the soil has been shown to reduce clubroot
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