Hot water and cutting for control ofImpatiens glandulifera

Abstract

Ornamental jewelweed (Impatiens glandulifera Royle) is an alien invasive plant in Europe. This annual plant often grows in riparian habitats where herbicides are prohibited. Several studies have reported the negative effect on ecosystem and ecosystem services by this species. However, limited research is published on control measures and the aim of our study was to explore use of hot water and cutting to control I. glandulifera. A lab experiment showed that the lethal water temperature for seed was between 45 and 50 C. In a pot experiment with seeds in soil, emergence of I. glandulifera was reduced by 78% and 93% compared with the untreated control with volumes of hot water (80 C) of 7.2 and 14.5 L m−2, respectively. When treatments were conducted on relatively tall plants (almost 60 cm) in late June, hot water gave significantly better control than cutting. Compared with an untreated control, I. glandulifera cover was reduced by 97% and 79% after hot water and cutting, respectively. Application of hot water to smaller (<40 cm) and less developed plants (BBCH 12–13) in early June and cutting of plants with visible flower buds (mid-July) led to no significant difference in cover. Compared with an untreated control, I. glandulifera cover was reduced by 99% (cut below first node) and 91% (hot water and cut above first node). When relatively tall plants (almost 60 cm) were treated, hot water use was high (31.1 L m−2) and required twice as many work hours (4.8 min m−2) as cutting (2.4 min m−2). When smaller plants (<40 cm) were targeted, work hours and hot water use were reduced to 2.1 min m−2 and 13.7 L m−2, respectively.

Effects of Hot Water Obtained by Solar Energy on the Weeds Convolvulus arvensis L., Setaria viridis (L.) P. Beauv. and Amaranthus retroflexus L.

“…While hot water application can control weeds, it has been reported that at much lower doses the seeds of Impatiens glandulifera, a problem in European countries, lose their ability to germinate. When comparing the effects of mowing and hot water in controlling Impatiens glandulifera, they reported that applying hot water at different stages of plant growth was more effective than mowing and that applying hot water in the early and late stages could save 50% of the water used (Oliver et al, 2020). The results of this study parallel the results obtained in our study.…”

Biological flora of Central Europe: Impatiens glandulifera Royle

“…Can$21,000 ha -1 in Québec, Canada) (Leblanc and Lavoie, 2017). Spraying hot water of 80°C on the plants has also been tested as a management strategy, but cutting is more time and cost efficient (Oliver et al, 2020).…”

A Modeling Framework to Frame a Biological Invasion: Impatiens glandulifera in North America

“…Thus, habitat restoration is a must, along with removal [ 58 ]. Chemical control is an available [ 75 ] but a not yet viable choice for riparian habitats [ 183 ]. Mechanical control is expensive and laborious [ 184 ].…”