SYNERGISTIC ANTIMICROBIAL COMPOSITIONS

Abstract: An antimicrobial composition comprises, in combination, an antimicrobially effective amount of active compounds including: a) formalin and b) between 100 ppm of Imazlyle or pitrizate, or a mixture thereof, for one part of formalin, and up to 60 % by weight.

Description: SYNERGISTIC ANTIMICROBIAL COMPOSITIONS Field of the Invention The present invention relates to synergistic antimicrobial compositions with a wide spectrum of activity, exhibiting deep penetration into the soil, and to methods for soil and substrate disinfestation. Background of the Invention Methods for inhibiting microbial growth have been widely disclosed in the art. For instance, U.S. Patents Nos. 3,833,951, 3,887,922 and 3,644,380 disclose 2-bromo-2-bromomethylglutaronitrile, which is used as an antibacterial, antifungal agent. Formaldehyde is a well-known and widely used compound. Both 2-bromo-2-bromomethylglutaronitrile and formaldehyde are known individually as antimicrobial agents. The mixture comprising the two abovementioned compounds also has antimicrobial activity. U.S. Patent No. 3,699,231 discloses a method for inhibiting microbial growth in substances and a biocidal composition which contains sodium dimethyldithiocarbamate and formaldehyde. U.S. Patent No. 3,699,231, discloses a biocidal composition which contains a mixture of at least one aldehyde selected from the group consisting of paraformaldehyde (HO(CH2θ)H) and at least one carbamate. U.S. Patent No. 4,356,179 relates to a method of preventing and treating diseases in chestnut trees and in peach, plum and black cherry, caused by fungi or bacteria, and comprises an aqueous solution containing an amount of formaldehyde effective against said fungi or bacteria. All prior art compositions of this kind present severe disadvantages, either with respect to efficacy, or environmental problems, or both. The present invention provides a wide spectrum of activities to control soil-born pathogens of bacteria, fungi and nematodes and can be used for a very wide range of crops, and gives control to soil depths unattainable by the prior art. It can be used in the open fields, as well as in greenhouses. Another advantage of the invention is that there is no need to cover the treated soil with plastic sheets, as the compositions of the invention are environmentally friendly. It is therefore an object of the present invention to provide synergistic antimicrobial compositions that overcome the shortcomings of prior art compositions, in respect of both efficacy and depth of penetration. It is another object of the invention to provide antimicrobial compositions with wide spectrum, which are environmentally friendly. Other objects and advantages of the invention will become apparent as the description proceeds. Summary of the Invention The present invention relates to synergistic antimicrobial admixtures with a wide spectrum of activity, permitting a deep penetration into the soil and leaving no residue. According to the invention there are provided new and improved biocidal compositions containing formalin, together with imazlyle (±Alil LL-(2,4dichlorophenyl) 2-imidazol-L-ylethyl ether) and/or with pitrizate (Thiabendazol-2(thiazol-4-yl) benzimidazole). Synergistic compositions comprising imazlyle and formahn will be referred to hereinafter as Fordor 101 (or F-101), for the sake of brevity. Similarly, compositions containing formalin and pitrizate will be referred to as Fordor 102 (or F-102), and compositions containing Formalin, Imazlyle and pitrizate, will be referred to as Fordor 103 (or F-103). The ratio between one unit of Formahn to the other active compounds (i.e., imazly, or pitrizate or their mixtures) is between 100 ppm of Imazlyle or Pitrizate or their mixture for one part of formalin, and up to to 60% by weight. The ranges for the concentrations of the various mixtures in inert carriers is 70% or less. The amount of Imazlyl formulation to be added to formalin is typically, but non-limitatively, in the range of 50 to 100 ml in 200 to 500 liter Fordor 37, which can be applied to 1000 m 2 of soil. Similarly, for Pitrizate, between 500 and 2000 gr. of Pitrizate composition can typically be used in 200 to 500 liters of formahn, to cover 1000 m 2 of soil. A convenient formalin composition to be used for the purposes of the invention is Fordor 37 (ex Dor Chemicals), which contains formaldehyde 36.5±1%, methanol 3-8%, additives 0-1%, and H 2 O to 100%. Additial active ingredients can be formulated together with the compositions of the invention, to provide additional activity. Illustrative and non-limitative active ingredients of this type are, e.g., the following: • Organophosphorus nematicides; • Organophosphate nematicides • organothiophosphate nematicides; • unclassified nematicides; • Fenamiphos; • Cadusafos; • Dezomet. The invention also provides a method for soil and substrate disinfestation, comprising adding thereto an effective microbial growth-inhibiting amount of a biocidal composition of the invention. The method and composition of the invention are useful in controlling the harmful effects of a variety of microorganisms and pests that affect crops. Microorganisms which are effectively controlled by the compositions of the invention include, but are not hmited to: a) Bacteria e.g.: Streptomyces sp., Pseudomonas spp., Erwinia spp., Xanthomonas spp., Clavibacter spp., Corinebacterium spp., b) Soil-borne Fungi, e.g.: Pythiun spp., Fusarium spp., Verticilium spp., Coletotricum spp., Helminthosporium spp., Rhizoctonia spp., Sclerotinia spp., Sclerotium spp., Botrytis spp., Monosporoasccus, Olpidium spp., phytophthora spp. and more; and c) nematodes spp. ("nematodes", in this context, being limited to those of the group of free living nematodes or migratory nematodes only), when the crop to be treated is potatoes; Streptomyces sp. and pythiun sp. when the crop is peanuts; pythiun sp., Erwinia sp., and Streptomyces sp. when the crop is carrots; Clavibacter pseudomonas corrugate, Erwinia sp., nematodes, pythiun sp. and pseudomonas solanacearum when the crop is tomatoes; and pseudomona corrugate, clavibacter, Erwinia sp., Xanthomonas sp., Pythiun sp. and nematodes, when the crop is pepper. The compositions of the invention can be used to control harmful microorganisms in a variety of crops. Illustrative and non-limitative examples of crops which can benefit from the invention include those that are affected by soil borne pathogens (bacteria, fungi or nematodes) such as vegetables, trees, flowers and ornamentals, cereals, legumes, fresh spices (herbs) in the open fields or in greenhouses and container media. The compositions of the invention can be administered in many different ways, such as during irrigation, by spraying, incorporation into the soil, etc. The synergistic antimicrobial combination of the present invention can be used in solid formulations, including powder or granular materials, or in liquids, such as in solution or emulsion. The carriers are chosen from liquid - water, alcohols, or solids - paraformaldehyde, Urea formaldehyde, with other solid compounds salts, inert materials, solid basic (which increase the pH when dissolved) compounds organic or inorganic. The compositions of the invention can be prepared by mixing the components together, or the synergistic antimicrobial combination of active ingredients may be used in combination with other antimicrobial materials, the antimicrobial combination containing the combination as the essential, active ingredient, which formulations also contain a variety of carrier materials, such as talc and the hke, or water, or various other organic liquids. The term "soil" as used herein is intended to include all media capable of supporting growth of plants, such as sand, compost and manure. The synergistic antimicrobial combination as described above should be applied in effective concentration of the active ingredients. Application amounts in the field range between 100 lit/1000 m 2 and 600 lit 1000 m 2 . Paraformaldehyde and urea formaldehyde concentrations range between 40 kg/1000 m 2 and 200 kg/1000 2 . In order to obtain effective results, direct contact between the synergistic antimicrobial composition and the pathogen is of course required. According to the present invention, the antimicrobial methods are beneficial not only by activity against bacteria and fungi responsible for inhibiting growth and destruction but in that it can improve crop production. All the above characteristics and advantages of the invention will be further understood through the following illustrative and non-limitative detailed description of preferred embodiments thereof. General Procedure An illustrative general application procedure is as follows. The soil should be after deep subsoiler with no clods and wet to the depth of at least 5 cm. In greenhouses, the application will be done after cleaning from leftovers. A. A Sprayboom with two beams with " t-jet " nozzles can be used, which should be in front and close-fitting to the rotevator. The rotevator should work to the depth of 10 cm., and behind it there should be a roller to seal the soil. In an hour the field should be watered to the depth of 30-40 cm. B. The soil disinfection should be done through a disconnected wipe. The injection should be at the point were the water goes into the line. It should be pumped into the line with a pressure higher by 1 atm. Then the water pressure would be in proportion to the water flow and would not be more than 0.7. The Fordor 37, which is one of the components, must be of a formulation suitable for agriculture, since agricultural grade Fordor 37 provides safety of the application, and later rapid degradation into non-toxic compounds. Experimental Procedure The tested materials (Fordor 37, Fordor 37 with the different additives or water as control) were applied on the top of test columns in an amount equivalent to a commercial application of 250 liter/1000m2. The columns were designed as two pieces with a longitudinal cut which, when combined together, had the dimensions of 15 x 15 x 40 cm. By using such columns, it was possible to open them after the desired time from the application, and to take samples of soil from each soil level (depth). In addition, the media -o- passing through the columns were collected at different times for the purpose of checking for residual activity against tested organisms. In all experiments reported below, the following components were used: Imazlyl (ex Scipec, Israel, 950/HZ 86), in 47% active compound formulation. In the tested formulations 100 cc of Imazlyl were used for each 250 liter of Fordor 37, including when both Imazlyl and Pitrizate were used together. Pitrizate (ex Assia Rizel, Israel, 295/HZ 76), in 43% active compound formulation. In the tested formulations 2000 gr. of Pitrizate were used for each 250 liter of Fordor 37 per 1000 m 2 . The results, unless otherwise indicated, are in CFU per gram of soil. Statistical computations were carried out using sigma stat and sigma plot software. THE EXPERIMENTS All the experiments were done 3 times in 4 replications. The source of soil tested was a field with a known history of plant diseases such as Streptomyces (potato scab) , and fungi such as Verticillium of Fusarium. In each experiment the following was tested: 1) Water as a control. 2) Fordor 37 without additives. 3) The additive material in water as a carrier. The additives: 101 = imazlyle The additives: 102 = pitrizate The additives: 103 = imazlyle + pitrizate 4) Fordor 37 + the additive. F-101 Fordor 37 + imazlyle F-102 Fordor 37 + pitrizate F-103 Fordor 37 + imazlyle + pitrizate Example 1 The various compositions were applied to columns, as described above with reference to the general procedures. Results are shown in Table I and relate to the effect of the treatment on the population of Fusarium, Aspergilus, Verticillium and Streptomyces inoculated into different fraction collected under the columns and supplemented with all the chemical needs for the support of growth. Table I The results are given in % growth, which is the growth of microorganisms obtained in the treated soil, relative to that obtained in the control soil in which only water was used. The synergistic effect of the compositions of the invention is clearly seen. For instance, looking at the results for Aspergilus it is seen that the effect of Fordor 37 and of imazlyl in water are essentially similar, where both reduce the relative % of microbial growth (relative to water as 100%) to the order of 30% in the first four fractions (except in the first fraction of imazlyl in water), while F-101 reduces it essentially to zero. Example 2 The effect of the treatment on the population of Fusarium, Aspergilus, and Streptomyces was studied at different soil depths. Tests were carried out by adding the antimicrobial compositions to the soil at different depths (columns experiments) in concentrations of 1000 ppm (parts per million). The results are reported in Table II below. Microorganisms used in the tests were: Fusarium, Aspergilus, Verticillium and Streptomyces. Table II Example 3 The tested materials (such as Fordor 101, which comprises imazolyle and formalin) were applied into the soil. The size of the plots were 36 m x 18 m. The pattern of each experiment was water as a control in an amount of 250 liter/1000 m 2 ; Fordor 37 in an amount of 375 liter/1000 m 2 ; and Fordor 101 in an amount of 250 liter/1000 m 2 during irrigation of 60 m 3 water/1000 m 2 . The results are related to the effect of treatment on the population of fungi and in the potato crop and agricultural plants in the fields. After 80 days and 115 days from the starting point, samples of plants were checked for the presence of Verticilhum wilt. The results obtained with Fordor 37 and Fordor 101 treatment on the population of petioles and fungi showed that plants treated with Fordor 101 showed an incidence of Verticilhum wilt between 8 and 14%, those treated with Fordor 37 an incidence of 26%, and the control (water irrigation only) were 45% infested. As to Verticilhum, treatment with Fordor 101 reduced the percentage of infected plants to a mere 0.45 - 1.2%, from the 34.39% infected plants present in the control. Apphcation of Fordor 37 reduced the percentage of infected plants to 11.24%. All the above description and examples of preferred embodiments has been provided for the purpose of illustration, and is not intended to hmit the invention in any way, except as defined in the appended claims. Many changes can be carried out in the compositions of the invention. For instance, many microbially active or inert additives can be added to the compositions of the invention, and the compositions can be provided in different carriers. Furthermore, the compositions of the invention can be apphed to different crops and environments, using various methods and techniques, all without exceeding the scope of the invention.

Claims: CLAIMS; 1. An antimicrobial composition, comprising, in combination, an antimicrobially effective amount of active compounds including: a) formalin and b) between 100 ppm of Imazlyle or pitrizate, or a mixture thereof, for one part of formalin, and up to 60% by weight. 2. An antimicrobial composition according to claim 1, wherein the active compounds are contained in inert carrier materials. 3. An antimicrobial composition according to claim 2, wherein the inert carrier is talc. 4. An antimicrobial mixture composition according to claim 2, wherein the inert carrier is an organic solvent. 5. An antimicrobial mixture composition according to claims 2 to 4 wherein the amount of inert carrier is up to 70% by weight. 6. A composition according to any one of claims 1 to 5, further comprising one or more compound(s) selected from: • Organophosphorus nematicides; • Organophosphate nematicides • organothiophosphate nematicides; • unclassified nematicides; • Fenamiphos; • Cadusafos; • Dezomet. 7. A method for inhibiting microbial growth and for preventing or treating a microorganism-related disease in vegetable growth, comprising applying to said vegetable growth or to the soil an antimicrobial composition according to any one of claims 1 to 6. 8. A method according to claim 7, wherein the antimicrobial composition is apphed to the soil by spraying or by irrigation. 9. A method according to claim 6 or 7, wherein the diseased area is treated with an amount of antimicrobial composition of between 100 hters per 1000 m 2 to 600 hters per 1000 m 2 . 10. A method according to claim 6 or 7, wherein the diseased area is treated with a composition comprising an amount of paraformaldehyde and urea formaldehyde of between 40 kg/1000 m 2 and 200 kg/1000 m 2 .

Inventors: KRITZMAN GIORA, KRITZMAN, GIORA
Applicants: BAR ZVI, DOR CHEMICALS LTD, KRITZMAN GIORA, BAR, ZVI, DOR CHEMICALS LTD., KRITZMAN, GIORA
Application year: 2000
Main classification: A01N35
IPC codes: A01N35