Physical destruction of the sprouting ability of Elytrigia repens rhizome buds

Abstract

Traditional strategies for controlling Elytrigia repens infestations in organic cropping in Scandinavia are based on repeated post-harvest cultivation. However, post-harvest tillage is undesirable due to 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. A Danish project is investigating new technologies that can meet such requirements. One aspect is to look for methods that physically can destruct the sprouting ability of E. repens rhizome buds. We investigated the effect of heating using hot water and mechanical crushing by pressure on the sprouting ability of exposed rhizome buds. The effect of temperatures < 70oC on the sprouting ability was inversely related to exposure time while 70oC or more gave a complete bud kill irrespective of heat duration. A sigmoid function described the relationship between sprouting ability and increasing pressure with a complete bud kill attained at 10 Newton per mm rhizome length. Neither rhizome ecotype or rhizome length influenced the relationship when pressures produced a bud kill of agronomic interest (>70% control). According to energy calculations made, crushing rhizome buds appears far more promising than thermal destruction