Rhizome regeneration of Fallopia japonica (Japanese knotweed) (Houtt.) Ronse Decr. I. Regeneration rate and size of regenerated plants

Abstract

Japanese knotweed, Fallopia japonica (Houtt.) Ronse Decr. comes from submeriodional and oceanic areas of Eastern Asia. The material for our research was sampled from a Japanese knotweed stand situated on a SW oriented slope by a main road, under a line of family houses in construction. The part of the stand adjacent to the road was regularly mown by the Technical Services of the Banská Štiavnica town. The stand was 5 x 3 m in size. The experiment was running over two growing seasons: 2002 and 2003. The study material consisted of 30 rhizome segments with three different lengths (2 cm, 5 cm, 8 cm). The plants had been regenerated in the following proportions: 90% exemplars of 8 cm segments, 63% of 5 cm segments and 60% of 2 cm resulted in new plants towards the end of experiment No 1. Experiment No. 2 gave rather different results: by 70% regenerated exemplars in case of 8 cm and 2 cm segments, 67% in case of 5 cm segments. The reasons of these differences are explained in the discussion. The growth dynamics and final size of the regenerated plants were dependent on the segment length.