Perennial weed control by deep placement of volatile soil fumigants
Palabras clave
Información de patente
| Número de patente | 3964405 |
| Archivado | 03/04/1971 |
| Fecha de patente | 06/21/1976 |
Abstracto
Reclamación (es
We claim:
1. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle by the deep injection of volatile soil fumigants at least fourteen inches below the soil surface at a horizontal spacing under thirty inches and at least at a rate of two and one half gallons per acre.
2. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein 1-3 dichloropropene is injected.
3. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein 1-3 dichloropropene and related C 3 chlorinated hydrocarbons are injected together as the soil fumigants.
4. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein methyl bromide fumigants are injected.
5. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein ethylene dibromide fumigants are injected.
6. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein 1-3 3 dichloropropene and methyl bromide fumigants are injected together as the soil fumigants.
7. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein 1-3 dichloropropene and ethylene dibromide fumigants are injected together.
8. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein 1-3 dichloropropene, methyl bromide and ethylene dibromide fumigants are injected together.
9. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein deep injection occurs in a range of fourteen to twenty four inches below the soil surface.
10. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein deep injection occurs at horizontal spacings in a range of sixteen to thirty inches.
11. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein deep injection occurs at rates in a range of two and one half to thirty gallons per acre.
12. A method of controlling deep rooted perennial weeds such as bind-weed and Canadian thistle, as claimed in claim 1, wherein the injection occurs in a range of fourteen to twenty four inches below the soil surface, at horizontal spacings in a range of sixteen to thirty inches, and at a rate in a range of two and one half to thirty gallons per acre.
13. A method of controlling deep rooted perennial weeds such as bindweed and Canadian thistle, as claimed in claim 12, wherein the volatile soil fumigants are selected from the group consisting of 1-3 dichloropropene, methyl bromide, and ethylene dibromide and mixtures of the foregoing.
Descripción
BACKGROUND OF THE INVENTION
Perennial weeds, such as morning glory, also known as field bindweed, have not been adequately controlled and millions of acres of fertile farm land are severely infected. Residual herbicides and persistant soil sterilants have been used through application to foliage, soil surfaces and shallow incorporation into soil. However, the application costs have been high and adequate control has not been achieved. Moreover, there are disadvantages, such as: residual chemicals remain in the soil; there are partial losses of one or more crops, due to toxic chemicals; there is the potential of chemical residue contamination in successive food crops; and there is the possibility of the unwanted movement of the toxic entity of chemicals to other areas by leaching and/or surface run-off in natural water. In general, the application of any residual chemical to soil or foliage has the inherent danger of polluting the environment through contamination of ground and surface water. As a result, restrictions have been placed on the current usage of many chemicals formerly used in gaining some control over morning glory, Canadian thistle and other perennial weeds. This invention therefore is directed to effectively controlling and often eliminating the growth of these perennial weeds, while avoiding the unwanted after effects and complying with the directives of government agencies.
SUMMARY OF INVENTION
Many destructive perennial weeds, well identified for many years, can be kept under control and often eliminated by utilizing chemicals also known for many years. These known chemicals are now employed in different mixtures, different combination, at different rates, applied in different ways and in different locations. For example, morning glory, also known as field bindweed or Convolvulus arvensis, and Canadian thistle also known as Cirsium arvense, are both controlled and often eliminated by the deep placement of volatile, non-persistant chemical soil fumigants. The latter are fumigants containing: 1,3 dichloropropene and related chlorinated C 3 hydrocarbons, methyl bromide and/or ethylene dibromide. These chemicals are placed from 14 to 24 inches below ground level at 18 to 30 inches of horizontal spacing and applied at rates ranging between 2.5 to 30 gallons per acre. Their deep placement is accomplished: by using spot penetration injectors; through operating special furrowing equipment; and by utilization of tooth or chisel applicators generally attached to cultivators.
DESCRIPTION OF THE INVENTION
Deep direct placement of soil fumigants 16 to 24 inches below the surface is undertaken to eradicate, from the lower soils, the roots and stems of perennial weeds such as: Canadian thistle known also as Cirsium arvensis, and morning glory known also as field bindweed or Convolvulus arvense. The deep placement occurs upon operating spot penetrating injectors, special furrowing equipment; and tooth or chisel applicators generally attached to cultivators. The soil fumigants injected are: 1-3 dichloropropene containing fumigants, and known by various names and designations such as Telone, Vidden-D, DD, 1-3 D, and Vorlex; methyl bromide containing fumigants and known as MB; and/or ethylene dibromide containing fumigants and known as EDB.
EXAMPLES OF EFFECTIVE CONTROLS
EXAMPLE I
The following table summarizes the application of various types of soil fumigants containing 1-3 dichloropropene to morning glory also called field bindweed and Convolvulus arvensis contained in plastic soil tubes, at a temperature of 68.degree. F for a 14 day period. The rate of application was based on 0.0869 ml per cubic foot of soil or expressed as 1 gallon per acre. The live root weights are the actual weights of the live roots at locations respectively of 6 and 12 inches from the specific point of the injection of the soil fumigants.
______________________________________ Soil Rate Live root weight in grams Fumigant Gal/Acre 6" distance 12" distance from place of injection ______________________________________ Control 0 3.8 3.4 Vidden-D 3.75 1.4 3.2 (50 - 60% 1,3-D) 7.50 0.0 2.5 Telone 2.50 0.7 3.7 (80% 1,3-D) 3.75 0.6 2.3 7.50 0.0 1.7 1, 3-D 3.75 0.2 1.3 (90% analysis) 7.50 0.0 0.9 ______________________________________
EXAMPLE II
The following tables summarize the application of various soil fumigants to morning glory, also called field bindweed and Convolvulus arensis. The soil fumigants were DD which is 1-3 dichloropropene plus C-3 hydrocarbons, EDB which is ethylene dibromide, and 1-3D which is 1-3 dichloropropene, a 90% analysis. The soil fumigants were applied in plastic soil tubes and were effective as the temperature remained at 68.degree. F. In the first table, the live root tissue weights were observed after 44 days of exposure, and in the second table, the live root tissue weights were observed after 30 days of exposure.
______________________________________ 44 days of exposure Soil Rate Live root weight in grams Fumigant Gal/Acre 6" distance 12" distance from place of injection ______________________________________ Control 0 14.3 13.6 DD 7.5 4.7 9.2 15.0 2.8 6.9 DD plus EDB 7.5 1.0 6.1 (17 plus 3)** 15.0 2.2 2.8 EDB 18/lbs gal. 2.5 2.2 6.4 1,3-D 8.5 0.3 3.4 (90% analysis) ______________________________________ ** Mixture of 17 parts of DD, and 3 parts of EDB at 18 pounds per gallon of active material.
______________________________________ 30 days of exposure Live root Soil Rate weight in grams Fumigant Gal/Acre along 18" vertical axis ______________________________________ Control 0 29.3 Telone 12.5 2.9 DD 20 4.3 DD + EDB (17 + 3 parts) 20 3.0 DD + EDB (18.5 + 1.5) 20 3.0 EDB 18 lbs/gal 2.5 10.7 ______________________________________
EXAMPLE III
The following table summarizes the application of various soil fumigants to morning glory, also called field bindweed and Convolvulus arvensis. The soil fumigants were applied in plastic soil tubes when ambient air temperatures ranged between 35.degree. and 60.degree.F. for an exposure period of 42 days.
__________________________________________________________________________ 4" from injection point 7" from injection point Soil Rate Shoot to % control Shoot to % control Fumigant Gal/Acre root ratio Ck = 0% root ratio Ck = 0% __________________________________________________________________________ DD 5 13.8 61.6 17.5 37.1 DD 10 9.7 61.8 14.6 55.6 DD 15 3.4 96.3 8.7 63.0 Telone 5 8.7 61.6 16.5 40.8 Telone 10 6.3 80.8 3.5 92.6 Telone 15 0.0 100.0 2.6 92.6 MB 5 5.7 96.3 10.4 74.1 Control 0 24.3 0.0 22.5 0.0 __________________________________________________________________________
EXAMPLE IV
The following table summarizes the application of various soil fumigants to morning glory, also called field bindweed and Convolvulus arvensis. The soil fumigants were applied in field plots of 3000 sq. ft. Also during the year of chemical application wheat was planted and the yields were observed.
__________________________________________________________________________ Bindweed Colonies/Plot Wheat Yield Soil Rate Plot 1 Plot 2 Ave. Plot 1 & 2 Fumigant Gal/Acre 3000 sq. ft. 3000 sq. ft. Bushels/Acre __________________________________________________________________________ Control 0 89 46 73.6 1-3D-Telone 15 8 0 76.7 1-3D-Telone 25 1 2 76.0 1-3D-DD 15 2 12 76.0 1-3D-DD 25 2 26 76.0 __________________________________________________________________________
EXAMPLE V
The following table summarizes the application of various soil fumigants to morning glory, also called field bindweed and Convolvulus arvensis. The soil fumigants were applied deeply in plots of 1,800 sq. ft. at horizontal spacings of 30 inches and in other plots of 1,800 sq. ft. at horizontal spacings of 20 inches. The soil fumigants, by using a shank implement, were injected 16 inches deep below the surface of the soil.
______________________________________ Soil Rate Horizontal Bindweed Fumigant Gal/Acre Spacing Colonies/Plot ______________________________________ Vidden-D 15 30 23 Vidden-D 15 20 13 Vidden-D 25 30 12 Vidden-D 25 20 3 Control 0 20 25 ______________________________________
SUMMARY OF ADVANTAGES OF INVENTION
Perennial weeds and especially the very damaging ones commonly known as morning glory and Canadian thistle are controlled and often eliminated by deeply placing volatile chemical soil fumigants 14 to 24 inches below ground level at 18 to 30 inches of horizontal spacing and applied at rates ranging between 2.5 to 30 gallons per acre to destroy their vegetative and reproductive roots. Volatile chemicals injected are soil fumigants containing respectively: 1-3 dichloropropene, methyl bromide, and/or ethylene dibromide. Deep placement and injection is undertaken by operation of: spot penetrating injectors; furrowing equipment; tooth or chisel applicators attached to tractor mounted cultivators and trailer-type cultivators.
The control and/or elimination of these perennial weeds is undertaken economically and without creating undesirable side effects. The deep injection places the fumigants so they cannot emerge or be leached, and then be carried by surface or ground water. Also the chances of the fumigants being carried away as vapor is very unlikely after their deep injection. Any possible emergence, would involve a low concentration of a fumigant which has been very well broken down. After five to seven days the fumigant is no longer detected above the surface and there are no long term pollution effects. Often times the productivity of the resulting cleared cultivated land is increased.
