Physical destruction of the sprouting ability of Elytrigia repens rhizome buds

Melander B, Mathiassen SK, Nørremark M, Kristensen EF, Kristensen JK & Kristensen K (2011). Physical destruction of the sprouting ability of Elytrigia repens rhizome buds. Weed Research51, 469–477.SummaryElytrigia repens is a perennial grass that spreads mainly by rhizomes. It is controlled by repeated post‐harvest cultivations in organic cropping in Scandinavia. However, post‐harvest tillage is undesirable, because of the need for retaining nutrients in the cropping systems. There is a need to look for solutions where E. repens can be controlled over a short duration to allow replanting of the soil. New technologies are required, and one aspect is to look for methods that can destroy the sprouting ability of E. repens rhizome buds. We investigated both the effect of heating using hot water and mechanical crushing by pressure, on the sprouting ability of exposed rhizome buds. The effect of temperatures <70°C was inversely related to exposure time, while 70°C or more gave a complete bud kill irrespective of heat duration. Rhizome buds responded to increasing mechanical stress in a sigmoid manner, similar to other studies with physical stresses, but with no support for a symmetric point of inflection. A 80–95% bud kill was attained within a range of 3.5–9.5 Newton per mm rhizome length, depending on the rhizome ecotype. According to energy calculations made, crushing rhizome buds appears far more promising than thermal destruction.