GB2281698A - Treatment of polygonaceous plant material - Google Patents

Abstract

A land area such as grassland is treated with a formulation containing a selenium salt, e.g. sodium selenite, so as to substantially eradicate growth of polygonaceous plant material (such as dock leaves).

Description

Eradication of Polygonaceous Plant Material The present invention is concerned with the treatment of land areas so as to eradicate polygonaceous plant material, and in particular dock leaves.

The growth of polygonaceous plant material, such as dock leaves, on grasslands is particularly undesirable. Currently used herbicides to counteract this growth are expensive, and tend to be unselective in destroying desirable plant growth as well as the growth of the polygonaceous material.

We have now developed a formulation which alleviates the above problem.

According to the present invention there is provided a formulation containing a selenium salt, for use in substantially eradicating the growth of polygonaceous plant material.

According to a first embodiment of the present invention, the formulation comprises an aqueous carrier, diluent or excipient, preferably containing the selenium salt dissolved therein. In this way, the formulation can be administered to selected grassland, pastureland or the like, by suitable techniques such as spraying.

Preferably the carrier, diluent or excipient consists essentially of water, which may, if desired, have been purified to substantially remove unwanted contaminants, such as heavy metals or the like, therefrom.

It is preferred that the selenium salt is dissolved in the carrier, diluent or excipient at a level of about lg/litre. Advantageously the concentration of selenium salt is selected such that approximately 120 to 150 litres of carrier, diluent or excipient (thereby delivering about 120 to 150g of selenium salt) can be administered to about one acre of grassland, pastureland or the like.

According to a second embodiment of the present invention, the formulation comprises a concentrate containing a selenium salt, which concentrate is suitable for intimately mixing with an aqueous carrier, diluent or excipient substantially as hereinbefore described.

The concentrate may be in powder or tablet form, suitable for dissolving in the carrier, diluent or excipient. Alternatively the concentrate may comprise a liquid medium, containing a selenium salt, which medium is substantially miscible with the aqueous carrier, diluent or excipient, so as to provide a formulation of desired concentration, advantageously about lg/litre.

It is preferred that the selenium salt in the formulation according to the present invention comprises a selenite, although other agriculturally acceptable selenium salts (such as selenates) could also be employed. Sodium selenite is most preferred.

The formulation is preferably particularly active against polygonaceous plant material, such as dock leaves or the like. It is preferred that the formulation is selectively active against polygonaceous plant material. Advantageously, the formulation is substantially inactive with respect to desirable plant growth, such as the growth of papilionaceous plant material (typically clover or the like).

The formulation is preferably further capable of delivering selenium to a treated land area, such that ruminants grazing on the land area can take up the released selenium. This is particularly beneficial as the formulation can provide a source of elements, such as selenium, for grazing ruminants.

There is therefore further provided by the present invention a formulation containing a selenium salt, for use in substantially eradicating the growth of polygonaceous plant material, and providing a source of at least selenium for ruminants grazing on a land area having been treated by said formulation.

The formulation may further comprise other beneficial ingredients, such as minerals, vitamins or the like, which can contribute to the general well being of the ruminants.

There is still further provided by the present invention a method of treating a selected land area, such as grassland, so as to substantially eradicate the growth of polygonaceous plant material thereon, which method comprises administering a formulation containing a selenium salt to said land area, so as to substantially eradicate growth of said polygonaceous plant material.

It is particularly preferred that the formulation comprises a selenium salt, such as a selenite, dissolved in an aqueous carrier, diluent or excipient. This is particularly beneficial, in that the formulation is suitable for spraying onto grassland.

Advantageously the selenium salt is dissolved in the aqueous carrier, diluent or excipient at a level of about lg/litre. It is preferred that approximately 120 to 150 litres of the formulation are administered to about one acre of grassland. At this concentration, the selenium salt is selectively active against polygonaceous plant material, whilst being substantially inactive with respect to desirable plant growth, such as papilionaceous plant growth.

Preferably the formulation comprises sodium selenite substantially as hereinbefore described.

The method preferably further comprises monitoring the treated land area, so as to observe the effect of the administered selenite on the polygonaceous plant material.

The monitoring is preferably carried out at least initially a few days after administration of the formulation, and may advantageously further comprise monitoring the growth of the polygonaceous plant material in subsequent seasons.

The method may include an initial administration of the formulation which contains the selenium salt, followed by a period of growth monitoring as described above, and further administration of the formulation if it is observed that the initial formulation administration was insufficient to substantially eradicate polygonaceous plant growth.

The method may further comprise administration of a formulation containing a selenium salt in subsequent seasons following initial administration. This administration in subsequent seasons is typically required, when the effects of the initially administered formulation have substantially deteriorated and new growth of polygonaceous plant material is observed.

The present invention will now be further illustrated by the following example which does not limit the invention in any way.

Example 150g of sodium selenite were added to 150 litres of water, and the mixture agitated to ensure thorough solvation of the selenite in the water.

The mixture was then sprayed onto an acre of grassland in which dock leaves were prevalent. The treated grassland was then monitored.

Within two days of the treatment the dock leaves were showing visible distress, and were destroyed within one week of the treatment. The formulation was seen to have no detrimental effect on other plant growth, such as clover.

Claims (10)

Claims:

1. A method of treatment of a selected land area, which comprises administering thereto a formulation containing a selenium salt so as to substantially eradicate growth of polygonaceous plant material in said land area.

2. A method according to claim 1, in which the formulation contains an aqueous carrier, diluent or excipient.

3. A method according to claim 2, in which the carrier, diluent or excipient consists essentially of water.

4. A method according to claim 2 or 3, in which the selenium salt is in solution.

5. A method according to any of claims 1 to 4, in which the selenium salt is administered at a rate of 120 to 150 grams per acre of grassland.

6. A method according to any of claims 1 to 5, wherein the selenium salt comprises a selenite.

7. A method according to claim 6, wherein the selenite comprises sodium selenite.

8. A method according to any of claims 1 to 7, wherein said formulation is applied by spraying.

9. A formulation containing a selenium salt, for use in substantially eradicating the growth of polygonaceous plant material.

10. A formulation according to claim 9, which is as defined in any of claims 2 to 7.