AUTHOR=Chichinsky Daniel , Larson Christian , Eberly Jed , Menalled Fabian D. , Seipel Tim 

TITLE=Impact of Puccinia punctiformis on Cirsium arvense performance in a simulated crop sequence

JOURNAL=Frontiers in Agronomy

VOLUME=5

YEAR=2023

URL=https://www.frontiersin.org/journals/agronomy/articles/10.3389/fagro.2023.1201600

DOI=10.3389/fagro.2023.1201600

ISSN=2673-3218

ABSTRACT=<p><italic>Cirsium arvense</italic> (Canada thistle) is a perennial weed that causes significant economic losses in agriculture. An extensive rhizomatous root system makes <italic>C. arvense</italic> difficult to manage, particularly in agricultural systems that use tillage as a primary management tool. There is a need for the development of integrated weed management toolsets that include <italic>C. arvense</italic> biological controls. <italic>Puccinia punctiformis</italic> (thistle rust) is an autoecious fungal pathogen that systemically infects <italic>C. arvense</italic>, with the potential to reduce host vigor over time. The goal of this study was to integrate the <italic>P. punctiformis</italic> biocontrol with a simulated annual cropping sequence in a greenhouse environment and evaluate <italic>C. arvense’s</italic> above-and belowground biomass production, and its competitive ability. Repeated <italic>P. punctiformis</italic> inoculations produced systemically infected <italic>C. arvense</italic> stems in greenhouse pots over time. <italic>Cirsium arvense</italic> that was inoculated with <italic>P. punctiformis</italic> had 1.6 grams/pot (<italic>p = 0.0019</italic>) less aboveground biomass and 5.6 grams/pot (<italic>p&lt; 0.001)</italic> less belowground biomass, compared to the non-inoculated (control). <italic>Puccinia punctiformis</italic> and crop competition interacted additively to lower aboveground (p&lt;0.001) and belowground (p&lt;0.001) <italic>C. arvense</italic> biomass more than individual use of either the biocontrol or competition alone. The aboveground competition intensity of <italic>C. arvense</italic> in a mixed crop sequence, relative to non-inoculated <italic>C. arvense</italic> grown in a monoculture, was moderately impacted by the <italic>P. punctiformis</italic> biocontrol (<italic>p = 0.0987</italic>). These results indicate that systemic infection can reduce biomass production and the competitive ability of <italic>C. arvense</italic>. Overall, <italic>P. punctiformis</italic> can be integrated into competitive annual cropping sequences with the potential to reduce <italic>C. arvense</italic> vigor over time.</p>