Abstract
Tillage controls perennial weeds, such as Elymus repens, partly because it fragments their underground storage organs. However, tillage is difficult to combine with a growing crop, which limits its application. The aim of this study was to evaluate how soil vertical cutting with minimum soil disturbance and mowing affect the growth and competitive ability of E. repens in a grass–clover crop. A tractor-drawn prototype with vertical disks was used to fragment E. repens rhizomes with minimal soil and crop disturbance. In experiments performed in 2014 and 2015 at a field site close to Uppsala, Sweden, the rhizomes were fragmented before crop sowing (ERF), during crop growth (LRF), or both (ERF+LRF). Fragmentation was combined with repeated mowing (yes/no) and four companion crop treatments (none, Italian ryegrass, white clover, and grass/clover mixture). The results showed that in the grass–clover crop, rhizome fragmentation reduced E. repens rhizome biomass production and increased Italian ryegrass shoot biomass. ERF and LRF both reduced E. repens rhizome biomass by about 38% compared with the control, while ERF+LRF reduced it by 63%. Italian ryegrass shoot biomass was increased by 78% by ERF, 170% by LRF and 200% by ERF+LRF. Repeated mowing throughout the experiment reduced E. repens rhizome biomass by about 75%. Combining repeated mowing with rhizome fragmentation did not significantly increase the control effect compared to mowing alone. We concluded that rhizome fragmentation using vertical disks can be used both before sowing and during crop growth to enhance the controlling effect of grass–clover crops on E. repens.
Highlights
A rotational grass or grass-legume crop that combines competitive perennial crops and periodic shoot cutting makes it difficult for annual weeds to establish and set seed and for perennial weeds to build up their storage organs (Teasdale et al, 2007)
E. repens than when performed pre-sowing), the results indicate that there are some positive direct effects of the vertical disk treatment on the crop
Rhizome fragmentation through vertical disks has a reductive effect on E. repens rhizome and shoot biomass acquisition and increases the shoot biomass of grass–clover companion crops
Summary
A rotational grass or grass-legume crop that combines competitive perennial crops and periodic shoot cutting makes it difficult for annual weeds to establish and set seed and for perennial weeds to build up their storage organs (Teasdale et al, 2007). Shoot cutting retards plant development and biomass acquisition by severing valuable vegetative and propagative structures, and resets the light competition conditions. By losing less than their neighbors from shoot cutting, plants can gain a competitive advantage by it. Many perennial weeds are sufficiently competitive and robust to shoot cutting, to propagate within grass-legume crops (Vanhala et al, 2006; Thomsen et al, 2015). A few perennial weeds, e.g., couch grass [Elymus repens (L.) Gould], can cause severe problems in subsequent crops, with associated control and environmental costs. Non-chemical methods are needed that selectively target these weeds without damaging the crop, combining injury to the weed with an increased competitive advantage for the crop
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
