EP-4739111-A1 - HEATING SCREWS FOR THE TREATMENT OF INVASIVE PLANTS

Abstract

The invention relates to a method for treating soil containing invasive plants, which method comprises: - inserting and removing threaded heating elements into and from the subsoil; each of the threaded heating elements comprising a shaft (1) and a threading (3) in the form of helical blades arranged around central elements of the shaft along the entire length of the threaded heating element; the diameter of the threads (3) being 2 to 4 times greater than that of the cross-section of the shaft (1); the threads (3) being inclined between 20 and 40°; - heating the subsoil to a target temperature; the heating being controlled by temperature probes (6) placed between the threaded heating elements and lighting elements; - wherein a device controls the heating power depending on the temperature measurements taken by the temperature probes (6).

Inventors

• HAEMERS, Jan Emile
• Saadaoui, Hatem

Assignees

• The Soil Research Lab

Dates

Publication Date

20260513

Application Date

20240705

Claims (4)

1. 1. Method of treating soil containing invasive plants, comprising: - insertion and removal of threaded heating elements in the basement; - helical blades around the central elements of the shaft over the entire length of the drilling element; - the diameter of the threads is 2 to 4 times greater than that of the shaft section; - the nets are inclined between 20 and 40°; - heat the basement to a target temperature; - the heating is controlled by temperature probes placed between the heating elements and the lighting elements; - where a device controls the heating power based on temperature measurements.
2. 2. The method of claim 1, wherein the thermocouple sensors are threaded.
3. 3. The method of claim 1, wherein the heating elements are made of steel or an iron-based alloy.
4. 4. The method of claim 1, wherein the heating elements contain varying levels of heating power.

Description

HEATING SCREWS FOR THE TREATMENT OF INVASIVE PLANTS FIELD OF THE INVENTION The present invention relates to a method of heat treatment of soil affected by invasive plants or weeds, in particular Japanese knotweed. In a second aspect, the present invention also relates to a device for inserting a heating element into the floor, controlling the heating and automatically adapting the heating power to the target temperatures. The present invention relates to the technical field of soil treatment. CONTEXT Japanese knotweed is a widespread noxious weed in North America and Europe. It is found in natural areas, parks, gravel bars, along stream beds and banks, rights-of-way, and roadsides. It is also found in riparian areas and on uplands. Japanese knotweed thrives in moist soils or where roots can penetrate most soils. Plants often become established after being rejected from cultivated gardens or escaping from abandoned homes. Japanese knotweed also spreads through mechanical mowing and the inadvertent transport of cut rhizome segments into neighboring landscapes. Japanese knotweed, a member of the buckwheat family (Polygonacaea), is an erect, shrub-like, herbaceous perennial plant that often reaches a height of over 3 metres. As with all members of this family, the base of the stem above each joint is surrounded by a membranous sheath. The stems of Japanese knotweed are smooth (like bamboo), stout, and swollen at the joints where the leaf joins the stem. Although the size of the leaves varies depending on environmental conditions, age, and other factors, they are normally about 150 mm long and 75–100 mm wide, broadly oval to somewhat triangular, most often pointed at the tip, and are alternate on the stems. The stems are hollow, but may be waterlogged depending on soil moisture levels and where they are growing. The first or two lower nodes may often be filled with water. The small flowers, pale greenish-white, appear in pretty branched sprays in summer and are followed by small winged fruits. When they appear, the seeds are triangular, shiny, very small, about 2.5 mm long. Seeds cannot be produced in all growing situations, and normally not in conditions found outside the native range of Asia. Plants grow rapidly and often form large thickets or patches. The roots are rhizomes that can extend up to 10 m long. Buds along the rhizomes can develop into new stems depending on environmental and cultural conditions. Digging around the base of established plants encourages the development of new vegetative buds along the rhizome system. Japanese knotweed can spread by sprouts from the rhizomes of established plants and by sprouts from stems that have been cut from the parent plant. Roots and stems can develop when stem nodes come into contact with soils suitable for plant establishment. Known methods of controlling Japanese knotweed include foliar application. Foliar applications are made using spray equipment designed to apply small droplets to the entire plant (stems and leaves). They can be made using backpack sprayers or hose-end sprayers. Applicators should be careful to treat only the target species and not desirable surrounding vegetation. Foliar applications to new growth from rhizome segments and cane nodes have been shown to be effective on plants during the first 3 to 4 weeks of growth (less than 1.2 m in height). On established roots, spraying new growth may require multiple applications over several years to achieve control. This product is not recommended for riparian areas. Depending on the severity of the infestation, foliar applications may require repeat treatment during the growing season and possibly follow-up treatment in subsequent years. Another known method of Japanese knotweed control is cut stem applications. This involves cutting the Japanese knotweed stem between the first and second internode and applying it to the "well" created by cutting the internode in half. This method applies approximately 10 to 20 ml to the well. Depending on the site, there are several herbicide options for this application method. Cut stem applications have been shown to be 95% effective on mature plants. After 1.2 m of regrowth on the remaining stems, a second application to the cut stems or by injection should eliminate any regrowth. Another known method of controlling Japanese knotweed is stem injection, as in US 7,805,884 B2. Stem injection applications are made just below the first or second node, near the soil. Typically, a Japanese knotweed probe is used to create a small opening on each side of the stem, just below the node, to allow water to escape. A syringe metered to inject 5 ml of herbicide treatment delivers the treatment dose diagonally downward through one of the two holes closest to the applicator. The second hole can then allow pressurized water to escape if the node is full of water. Plants normally absorb the herbicide within 20 minutes of injection. The riparian injection process has proven