MXPA00001247A - Methods for fumigating soil - Google Patents

Abstract

The present invention provides for methods for fumigating soil containing deleterious organisms such as nematodes. The methods utilize an effective amount of acrolein which when added to the soil will control the organisms but will not exhibit phytotoxicity towards the existing or future plant life.

Description

METHODS TO FUMIGATE SOILS FIELD OF THE INVENTION The present invention relates to methods for fumigating soils to control harmful organisms. More specifically, the present invention suggests the use of acrolein to control noxious organisms in soils by minimizing or eliminating phytotoxic effects at the same time.

BACKGROUND OF THE INVENTION Fungi, bacteria, nematodes, viruses and insects can cause problems in soils destined for culture. This soil contamination will give rise to the drying of plants, problems of growth speed, root problems and decrease in production. In this way, the need to disinfest the soil is evident. There are several disinfestation methods. The sterilization at more than 100 ° C is a total biocide treatment. Pasteurization at 70 ° C will eliminate multiple pathogenic fungi and their specific survival forms. Chemical treatments can be divided into two classes: total disinfectants and biocidal activity or limited biostatics. Examples of disinfectants that are used with higher financial risks include chloropicrin, methyl bromide and methyl isocyanates. Biocides with limited activity include dichloroprene. Methyl bromide is an odorless gas that is applied to soils with or without the use of tarred plastic. Methyl bromide is a primary fumigant for controlling nematodes, weeds and fungi, mainly for tomatoes, ornamental plants, tobacco, peppers, strawberries and forest seedlings. One advantage of methyl bromide as a fumigant is that it evaporates; however, at 50 grams / m, methyl bromide leaves 10 to 20 ppm of bromide or bromine compounds as residue in the soil. However, due to the participation of the United States in the Montreal Protocol, compounds that have a detrimental effect on the ozone layer will be prohibited as of January 1, 2001. These compounds include chlorinated fluorocarbons (CFCs) and methyl bromide. The 150 countries participating in the Montreal Protocol of the United Nations are acting globally in what promises to be a complete shift of methyl bromide and CFCs. The economic effects of this prohibition in the United States and particularly in California and Florida are manifest. The economic losses for these two states can be enormous and a total of 900 million dollars if new fumigants are not found approved in time to replace methyl bromide. For this purpose, an alternative fumigant should be found that has attributes similar to methyl bromide (no toxic residues, effective and easy to use / economical). This fumigant must not leave toxic residues in the soil, it must be biodegradable and must be effective against a wide range of soil pathogens, as well as insects and nematodes. The present inventors have discovered means for using acrolein as a soil fumigant. Acrolein A is a known pesticide that is used to treat slime-forming microorganisms with liquid content. It has been found that acrolein effectively controls bacteria such as Bacill us subtllls, Pseudomonas putrefaciens and Escherichia coli; fungi such as Penlcill um Italicum, Saccharomyces cerevisae and Helminthospcrium turcic m; algae, macroinvertebrates such as snails and clams; and aquatic plants and weeds. Acrolein is also more effective than other biocides such as chlorine in the control of acroinvertebrates and submersed, as well as weeds and floating, aquatic algae. From an environmental point of view, acrolein is a good biocide because it is effective, it is easily eliminated and it is not expensive, and it is not persistent. Aqueous acrolein solutions are quickly and conveniently neutralized for disposal with sodium disulfite. This reaction produces a water-soluble, non-toxic salt. Acrolein is also neutralized by reaction with materials present in natural waters and, therefore, it is self-neutralizing. Also, a major advantage over methyl bromide is that it leaves no residue in the soil in addition to the normal carbohydrate residues, which can be easily assimilated by plants and other microorganisms. The present inventors have also discovered that acrolein can be administered to the soil as a fumigant while avoiding the normal effects of phytotoxity, which would otherwise prevent its use, by the specific application method. U.S. Patent No. 2,959,476 describes a method of aquatic life control in aqueous systems. This method is particularly directed to aquatic weeds and consists in adding a toxic amount of acrolein to the particular water body. U.S. Patent No. 3,250,667 describes a method of controlling microorganisms found in papermaking. This method uses acrolein to inhibit the formation of microorganisms that favor corrosion and form silt in the aqueous system of a paper-making plant. Fungi and bacteria are the main organisms responsible for sludge in aqueous systems in papermaking. US Patent No. 3,298,906 describes the use of acrolein acetals to protect a variety of plant parasitic nematode plants. This patent also discloses that acrolein acetals can be combined with other known fungicides to control a broader spectrum of fungi. U.S. Patent No. 3,380,462 describes a special system for using acrolein in a safe manner. This device suggests creating a controlled pressure zone in the liquid that is going to be treated and adding acrolein in this area. U.S. Patent No. 3,690,857 describes the use of acrolein diacetals in aqueous media to kill aquatic weeds and other unwanted life forms. This method will control the growth of aquatic organisms avoiding at the same time killing most of the fish present.

DETAILED DESCRIPTION OF THE INVENTION The present invention offers the methods for fumigating soils containing harmful organisms while controlling the phytotoxicity, which consists in adding an effective amount to the soil for the purpose of acrolein. For the purposes of the present invention, the term "an effective amount for the purpose" is defined as the amount of acrolein that when added to the soil will control the harmful organisms, but will not present phytotoxicity to the plants, due to specific methods and the timing of the addition Common soils that can be treated by the methods of the present invention are those that are used to grow food or ornamental crops such as strawberries, almonds, grapes, ornamental flowers, tobacco, tomatoes, melon, turf, apples, peanuts, lettuce, soybeans, onions, peaches, sugarcane, wheat, cherries and other field crops and ornamental species.The harmful organisms treated by the methods of the present invention include viruses, bacteria, fungi, insects and Nematodes The methods of the present invention will also be effective against other pathogens commonly found in soils. Applicants can obtain control of the harmful organisms by killing them without presenting phytotoxicity at the same time for the plants already present or expected to be planted. This effect is achieved not only by the amount of acrolein that is added to the soil, but by the way in which it is added. This form is important as acrolein is a known phytotoxic compound, and this form of addition will ensure acid effects by controlling phytotoxicity. Acrolein can be applied on the site by different known means. For example, acrolein can be supplied in cylinders or concentrated solutions such as those available to current acrolein manufacturers such as Degussa Corp. Another means of supply is by thermal decomposition at the site of the acrolein dimer (3, 4-dihydro-2H-pyran-2-carboxaldehyde or 2-formyl-3,4-dihydro-2H-pyran). This Generally, the acrolein diameter at 400 ° C at ambient pressure in a simple, packaged heat exchanger tube can be achieved. The acrolein dimer is available to Union Carbide Corp, as Presar, ® 1100. 1S A third means of producing acrolein is through the dehydration of glycerol by the reaction: H3P04 CBa-GH-CHs = * CHá? * CH - CHQ + 2H¿0 300 * 0 OH OH OH () This method is relatively inexpensive as glycerol and phosphoric acid are not expensive. However, there is a disadvantage in relation to the production of an acid residue that must be treated or discarded. Another means of producing acrolein is by oxidation of or propylene. This oxidation occurs with specialized catalysts at 45Q-500 ° C. This reaction is described in greater detail in U.S. Patent No. 5,081,314, the content of which is fully incorporated by reference herein. Another method for producing acrolein is demonstrated in U.S. Patent No. 5,079,266. This reference teaches the catalytic hydrolysis of an acrolein acetal to produce acrolein. The '266 patent, the content of which is fully incorporated by reference herein, teaches one of the safest ways to produce acrolein. As you can see, there are different ways to generate acrolein. Any of these can be used to generate acrolein used in the methods of the present invention. These differ in cost, safety and ease of production. Acrolein can be applied to soil containing harmful organisms by different methods. Acrolein can be sprayed on or injected into the soil. Proper soil cultivation before application is necessary as for other fumigants. For the purposes of the present invention, the soil is dosed with acrolein to establish the present demand. Once the demand is analyzed and established, a dose ratio from about 1 to about 100 grams / m is recommended upon request, with a rate of about 5 to 50 grams / m being most preferred. The analysis of the population of pests in the soil by conventional methods will allow the optimization of treatment levels. Common devices for applying chemical agents to the soil include a gravity flow applicator that is common for the treatment of furrows or smaller area. This type of injector can be of the chisel, tooth or cane type. The applications by plow can also be used particularly in light soils. Blade applicators are used to provide a uniform distribution of chemical agents at the depth of application. After application, of course, the soil must be sealed in a way that the acrolein does not escape as gas. The sealing methods can be as simple as laying on the ground covering with plastic for the time necessary for the chemicals to act. The acrolein used in the methods of the present invention can be added to the soil in any convenient medium that is compatible with the acrolein and the soil to be treated. One method would be acrolein in a solvent medium. Preferably this solvent is water, which if used will add penetration into the soil. Likewise, acrolein can be added contained in a polymer or gel where contact with water present in the soil will allow the polymer or gel to dissolve and allow the introduction of acrolein into the soil. Other delivery methods useful in the method of the present invention include microencapsulation or controlled release. Acrolein can be trapped in 13X Linde molecular sieves (activated). Approximately 20 to 25% of acrolein can be trapped based on weight. Trapped acrolein is stable under common conditions but is easily released in the presence of moisture. The diallylidene pentaerythritol (DAP) is an acrolein acetal in solid form which may be mixed with a solid acid such as sodium acid sulfate or sulfonic acid resin and a small amount of high molecular weight carboxymethyl cellulose. For example, 50% of DAP, 49% of NaHS04, and 1% of Hercules CMC HT in the presence of moisture will release acrolein in the soil. The rate of release will depend on the amount of water present. A means for controlling the phytotoxic effects of acrolein within the scope of the present invention is through the elimination of acrolein. By eliminating acrolein, it is possible to allow acrolein to control any or all of the harmful organisms and still render it incapable of phytotoxicity.

In "Environmental and Metabolic Destination of Acrolein in Water, Aquatic Sediments, Fish and Molluscs", Kovacs et al., The authors describe the results of tests showing that acrolein does not persist in the aquatic environment or aquatic species. In "Metabolic destiny of acrolein in plants or livestock", Loftus et al., The studies address the metabolism of acrolein in plants and animals and determine that acrolein does not persist in plants or animals. The natural and chemical degradation of acrolein will vary with pH, temperature and other soil conditions. In the presence of certain bacteria and chemical agents, acrolein will be biodegraded and / or converted into different carbohydrate compounds, as necessary for the organism. A more controlled method of elimination is by sulfite removal. Acrolein can be removed with sulfites and disulfites by the following reactions: S05Maf CH2 = CH-GHQ + NsHSO, ^ = * CH > m CrhCH I OH rort These reactions are very fast and represent an environmentally significant characteristic of acrolein. Two moles of sulphite are required at a minimum for each mole of e-p or Yor mine or mine for the iminium? "" 5 c- prefers an ammonium disulfite salt or sulfite salt solution. Another edio < - > 1 ii ?? na i ?? rio srr loína oc: rtr? am iriiaf n r ammonium compounds. The reaction products of acrolein and ammonia include propendiamine and other amines of C3 hydroxylated, all of which will be biodegraded ^ assimilated by plants and other soil organisms. An advantage of this method is that acrolein will react with ammonia or ammonium nitrate derived from fertilizers that may be present in or may be added to the soil.

Acrolein residues can be destroyed as such, in a few hours. To this end, some analytical tests have been developed to prove that acrolein (test method EPA 603 and NIOSH P and CAM 211) can be used in conjunction with detoxification methods. -7fl Acrolein has been tested and its properties have been demonstrated as a general biocide. The effectiveness of acrolein against mussels is described in "Chemical Control of the Establishment of Mussels in a Cooling Water System Using Acrolein", Rustenbil et al., 25 Environ. Pollut Ser. A., 25 (1981), 187, 195. Its effectiveness against Thlohaccillus ferroxldans has been demonstrated in US Pat. No. 5,171,454. U.S. Patent No. 5,500,220 demonstrates the effectiveness of acrolein against flour beetle, Tribollu ccnfusu Jaquelin du Val; the cigarette beetle, Lasicderma serricome; larvae of black carpet beetles, Attegenus unicolor all stages of life of the rice weevil, Si tophil us orvzae. "Evaluation of some non-halogenated compounds as fumigants against larvae of a fruit fly of the Caribbean" Carroll et al., Describes the efficacy of acrolein against Anastrepha suspensa. Although this invention has been described with respect to the specific embodiments thereof, it is evident that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be considered to cover all of these obvious forms and modifications that are within the true spirit and scope of the present invention.

Claims (5)

1. A method to control harmful organisms in soils consists in the steps of: (a) adding an effective amount of acrolein to the soil to control the harmful organisms; and (b) adding an effective amount of a compound to the soil to detoxify or eliminate acrolein.

The method of claim 1, wherein from about 1 to about 1QQ grams of acrolein are added per square meter of soil upon request.

3. The method as recited in claim 1, wherein the compound for detoxifying acrolein is selected from the group consisting of sulfites, bisulfites, ammonia and ammonium compounds.

4. The method as recited in claim 3, wherein the compound is the ammonium disulfide salt or the sulfite salt.

5. A method to fumigate soils that contain harmful organisms, includes the steps of: a) analyzing the soil to establish the demand for acrolein; b) adding an effective amount on demand for the purpose of acrolein to the soil; c) Detoxify the soil by adding a detoxifying agent selected from the group consisting of ammonia, ammonium compounds, sulfites and disulfites.