Regeneration and growth in crowns and rhizome fragments of Japanese knotweed (Reynoutria japonica) and desiccation as a potential control strategy

Abstract

Reynoutria japonica (Japanese knotweed) is a problematic invasive plant found in many areas of Europe and North America. Notably, in the UK, the species can cause issues with mortgage acquisition. Control of R. japonica is complicated by its ability to regenerate from small fragments of plant material; however, there remains uncertainty about how much (in terms of mass) rhizome is required for successful regeneration. This study investigated the ability of crowns and rhizomes with different numbers of nodes to regenerate successfully from three sites in the north of England, UK. Two of the sites had been subject to herbicide treatment for two years prior to sampling and the third site had no history of herbicide treatment. No significant differences were observed in regenerated stem diameter, maximum height of stem and maximum growth increments among crowns. All traits measured from the planted crowns were significantly greater than those of the planted rhizome fragments and at least one node was necessary for successful regeneration of rhizomes. The smallest initial fragment weight to regenerate and survive the experiment was 0.5 g. Subjecting all plant material to desiccation for 38 days resulted in no regrowth (emergence or regeneration) after replanting. These findings suggest that desiccation could be a valuable management strategy for small to medium scale infestations common in urban settings.

Anatomical characteristics and resprouting capacity of the underground organs of Bohemian knotweed (Polygonum ×bohemicum)

“…Previous studies on the resprouting capacity of Polygonum rhizomes already highlighted the high response capacity of Polygonum taxa in this respect, even in case of very small segments, as long as they are provided by a bud (Lawson et al 2021; Macfarlane 2011; Martin et al 2020). Existing literature additionally reports a better vegetative resprouting capacity of longer rhizome segments (Sásik and Eliáš 2006), of the hybrid genotypes (Bímová et al 2003; Pyšek et al 2003), as well as greater resprouting success in cases of overall higher density of nodes and related buds in the soil (Lawson et al 2021).…”

“…Existing literature on the resprouting capacity of rhizomes indicates a general higher resprouting potential of the hybrids with respect to parent taxa (Bímová et al 2003; Pyšek et al 2003) and an increasing resprouting capacity as a function of the segment length and number of nodes (Lawson et al 2021; Sásik and Eliáš 2006). If a node is present, however, very small segments can resprout (0.2 g to 0.5 g, according to Macfarlane et al [2011] and Lawson et al [2021], respectively), especially in case of young organs (Environment Agency 2013). Contrary to other rhizomatic species such as common reed [ Phragmites australis (Cav.)…”

Microwave Control of Reynoutria japonica Houtt., Including Ecotoxicological Aspects and the Resveratrol Content in Rhizomes

“…Managing invasive knotweeds is challenging due to their ability to accumulate significant below-ground reserves, allowing them to recover from various control methods, including physical, biological, chemical, and integrated approaches [ 19 , 20 , 21 , 22 ]. In the case of Japanese knotweed, some success has been achieved by focusing on seasonal resource translocation between above- and below-ground biomass and using suitable herbicide coverage or injections, such as glyphosate [ 19 , 20 , 21 , 22 ]. Another method involves physically burying rhizomes and stems [ 23 ].…”

Evaluation of the Main Macro-, Micro- and Trace Elements Found in Fallopia japonica Plants and Their Traceability in Its Honey: A Case Study from the Northwestern and Western Part of Romania

“…It forms dense groups of bushes that share a common rhizome structure [19] that can help them spread very quickly, together with sexual and clonal reproduction [37]. The stems are similar to bamboo sticks [38], having a woody consistency, the leaves are green and flattened, measuring 10-15 cm long, while the inflorescence contains multiple small flowers [3,39].…”