Insect repellent based on natural active ingredients and mineral carrier materials

Abstract

A repellent for psyllids comprises nonwhite clay minerals or a mixture thereof, optionally wetting agents, conifer fragrances in the form of pine needle extracts, sulfides such as pyrite and marcasite, organic substances such as humins and humic acids / fulvic acids and water for production of a spray suspension.

Description

[0001] INSECT REPELLENT BASED ON NATURAL

[0002] ACTIVE INGREDIENTS AND MINERAL CARRIER MATERIALS

[0003] The present invention relates to a biological pesticide based on mineral raw materials in the form of a repellent against psyllids, a process for its preparation and its use.

[0004] Interest in biological control of insect pests has arisen, among other things, as a result of the disadvantages of conventional chemical pesticides. Chemical pesticides generally affect both beneficial and harmful species. Insect pests acquire resistance to such chemicals, and new populations of resistant pests can rapidly evolve. Furthermore, chemical residues can pose a risk to the environment and cause health problems. Biological pest control may represent a suitable alternative to chemical pesticides in this regard.

[0005] Phytoplasmoses, for example, are dangerous diseases in fruit orchards and are transmitted by psyllids. In recent years, these diseases have spread increasingly, reducing fruit quality or causing the fruit trees to die completely. Controlling psyllids with insecticides has proven to be a highly environmentally damaging measure.

[0006] To prevent this, kaolin (a white rock powder or clay mineral) is used in organic pear cultivation, for example. The clay minerals make it difficult for insects to stay on the leaves. Suitable products are available commercially, such as Surround® or Cutisan®.

[0007] However, products based on kaolin or white clay minerals require improvement in several respects. For example, sprayed-on kaolin-containing solutions are relatively quickly washed off the trees by rain, creating or leaving an unnatural white film on the treated trees.

[0008] In a project funded by the German Federal Environmental Foundation (DBU), in which the applicant is also involved, a sprayable, clay-based, rainproof, stem-colored film (or spray solution) is to be developed to reduce the transmission of phytoplasmosis by repelling psyllids. Furthermore, if possible, the film will be infused with a conifer fragrance to enhance its repellent effect (DBU: Development of a biological repellent against psyllids).

[0009] The object of the present invention was therefore to develop a biological and as environmentally friendly as possible agent or a corresponding composition which can be used as a most effective repellent against, among other things, psyllids and which avoids as far as possible the disadvantages of the solutions known from the prior art.

[0010] This object is achieved by a composition or agent of the type described below, wherein this composition or agent is preferably used in a sprayable configuration or formulation.

[0011] The agents according to the invention are based on clay / clay minerals that are not white, but gray-brown, i.e., roughly bark-colored, and thus visually inconspicuous. Preferred clays are those from primary and / or secondary deposits. These are either illitic-chloritic, chloritic-vermiculitic, illitic-kaolinitic, or bentonite, whereby both pure Ca bentonites and activated Ca bentonites can be used. The three types of clay minerals, each type consisting of various representatives or mixtures thereof, are used alone or in a mixture, whereby the mixing ratio can preferably vary from 10:90 to 90:10 (illitic-chloritic clays: illitic-kaolinitic clays) (here and below, all data are in wt.%). Some preferred representatives of the clay minerals according to the invention are listed below:

[0012] - chloritic (Chlorites, Klinochlor, Chamosite)-illitic (Biotites, Muscovites)

[0013] - chloritisch-vermikulitisch (Chlorites, Vermiculites)

[0014] - kaolinitisch (Kaolinites, Fireclay, Dickites, N akrit)-i 11 itisch (Biotites, Muscovites)

[0015] - bentonite (Montmorillonites, Sapons, Nontrons, Beidellites, Hectorites)

[0016] The clayey raw materials preferred according to the invention differ significantly from the materials used in the prior art, not only in color (non-white), but also in granulometric terms. The clays preferred according to the invention already exhibit an extremely fine geogenic fineness, which can be further improved through an appropriate screening process. The reason for this is the different origin of the raw materials, the prior art, and that of the present invention. Kaolins used in the prior art products are generally coarser than clays; moreover, the remaining fines are elutriated during kaolin processing. For example, the proportion of the clay mineral fraction < 2 pm in the commercially available products is approximately 10%, whereas it is 31-55% for the clay mineral fraction preferred according to the invention.

[0017] The high fineness of the clays and the associated higher specific surface, preferably between 10 and 25 m 2 / g, offers the advantage of improved adhesion to branches of fruit trees, for example, when used as a spray suspension, compared to the more common and coarser kaolins. The washability of the fine-grained clays, e.g., by rain, is at least comparable to commercially available formulations that contain wetting agents in addition to kaolins. Thus, the wetting agent (chemical) can be omitted, or the spraying frequency in a single application season can be reduced, for example, from four to one or two times.

[0018] There is also an additional advantage when bentonites are used as clay minerals, either alone or as part of a mixture. Due to their surface charges and anion and cation exchange capacities, bentonites can incorporate or deposit various substances much better than other clays, especially kaolins. This includes, for example, improved deposition of fragrances.

[0019] The inventive composition (repellant) preferably contains no wetting agents. Should wetting agents be used, which could, for example, further increase wash-off resistance, the proportion of wetting agents in the composition is kept as low as possible, as they are an additive pursuant to Section 42 of the Plant Protection Act (preferred amounts (wt%) based on the clay minerals used: 0.001 to 0.005 wt%). Typical officially approved wetting agents include Wetcit, BreakThru, Trifol ioS-forte, and Zentero SPR.

[0020] Furthermore, the agents according to the invention can contain fragrances to increase repellency, which may be added to the agent shortly before spraying. In principle, any fragrance that repels psyllids is suitable. Conifer fragrances are preferred, especially fir and spruce needle extracts, and here, extracts of fir needles harvested at the transition from winter to spring are particularly preferred.

[0021] These pine needle fragrances usually include a fragrance spectrum that includes the following components:

[0022] These fragrances exhibit varying degrees of repellency. Camphene, camphor, limonene, and hexanal, or mixtures thereof, have been found to be particularly suitable for the purposes of the invention. These components can be identified and isolated from the resulting extract using known chemical methods (e.g., GC-MS; coupling of gas chromatography with mass spectrometry).

[0023] The extraction of the fragrances, e.g., from pine needles, can also be carried out using various known extraction methods, such as hot water extraction (65°C), which can also be repeated several times. The concentration of the fragrances depends on the amount of water used (e.g., 150 ml of water for 50 g of pine needles). A mixture of water to which approximately 10 wt.% ethanol is added shortly before incubation is also suitable as an extraction agent.

[0024] The content of fragrance or fragrance mixtures can vary within wide limits for the purposes of the invention. Preferred contents are 0.1 to 1 wt.%, based on the clay minerals used. The desired repellency can be achieved in various ways with the agents according to the invention. Firstly, the applied protective film provides so-called mechanical repellency, since the clay minerals prevent the substrates (fruit trees) from being punctured. Sulfides present naturally in the clays or admixed with them, such as pyrite or marcasite (FeS2), lead to additional repellency of the agents used, which can also be referred to as chemical repellency. Thus, the present invention also encompasses the combined use of clays and sulfides in a repellent. The sulfur content of these mixtures is preferably 0.1 to 1 wt.%, in particular 0.2 to 0.5 wt.%, based on the clay minerals used.

[0025] Furthermore, it has proven advantageous to further improve the good adsorption of the fragrances on the clay minerals used by using organic materials. For this purpose, clays containing organic substances (Corg = organic carbon) that are already naturally present geogenically in the clay can be added to the compositions or agents according to the invention. The organic substances themselves can also be mixed into the clays used. The compositions according to the invention preferably have Corg contents of 0.5 to 5 wt.%, in particular 2 to 4 wt.%, based in each case on the weight of the clay minerals used.

[0026] The Corg content is preferably characterized in that a mixture of humins and humic acids / fulvic acids is present in the clays or the added organic substances. The ratio (weight ratio) of humins to the sum of humic and fulvic acids is preferably 1 to 5, in particular 1.5 to 3. The total carbon content of a sample, organic and inorganic, from which Corg can then be determined, is determined according to the known Dumas method (combustion of the sample with oxygen at 1000° C. After determining Ctotal, Corg = C total - c carbonate). Thus, the compositions according to the invention comprise the following components, although not all of them have to be present at the same time: a) non-white clay minerals or mixtures thereof, wherein the proportion of the clay mineral fraction with grain sizes of < 2 pm is preferably 31 to 55 wt.%.Chloritic-illitic clays are preferably used alone or as a blending partner. b) Wetting agents, if necessary. c) Fragrances, preferably in the form of conifer fragrances, especially pine needle extracts, and here preferably the ingredients camphene, camphor, and / or limonene. d) Sulfides, such as pyrite and / or marcasite, which are naturally present in the clays used or are admixed with them. e) Organic materials, such as humins and humic acids / fulvic acids, which are naturally present in the clays used or are admixed with them or their compositions.

[0027] The aforementioned components a) to e) do not always have to be present in the composition according to the invention. The mandatory components are the aforementioned clay minerals or mixtures thereof. Otherwise, the invention also encompasses all possible subcombinations of components a) to e).

[0028] With regard to possible fragrances used, the invention comprises the following variants: 1 ) a composition which already comprises fragrances during the first production, and

[0029] 2) a composition in which the fragrances are only added by the user in order to avoid evaporation of the fragrances before the application of the composition or agent according to the invention.

[0030] Furthermore, the composition according to the invention can be presented as a dry or moist but solid composition, which is converted into a spray suspension by the user by adding water, or the composition can be presented as a concentrate to which additional water must be added before use, or the composition / agent can be delivered as a ready-to-use spray suspension. In all cases, production is carried out by mixing the components contained therein, preferably proceeding as follows:

[0031] 1 ) Production of the clay mixture from pit-wet clays

[0032] 2) Dosage of sulphides and / or carbon compounds, unless already geogenically contained in the clays

[0033] 3) Grinding of the clays to the target grain size distribution a) if necessary, additional fine screening to achieve the target grain size distribution b) if necessary, spraying the ground clays with the fragrance

[0034] 4) Preparation of the spray suspension at the customer's site a) If clay is supplied without fragrance, dosage of the fragrance in this process is required.

[0035] The spray suspensions according to the invention preferably contain the clays according to the invention at 1-5 wt.%, based on the finished spray suspension. The application rates (expressed in clay / ha) vary depending on the respective crop and are preferably:

[0036] Apple: 10-20 kg / ha Pear: 15-25 kg / ha

[0037] Cherry: 25-35 kg / ha

[0038] Olives: 20-30 kg / ha

[0039] Wine: 20-30 kg / ha

[0040] Rapeseed: 15-25 kg / ha

[0041] The number of treatment cycles (number / season) generally varies between 1 and 4 and naturally depends on the weather conditions (e.g., heavy or light rainfall). The main application periods for the products according to the invention are from February to April. The products are preferably applied before the first pests appear.

Claims

Patent claims 1. A means of repelling psyllids comprising a) non-white clay minerals or mixtures thereof, b) perfumes and c) optionally one or more surfactants.

2. Composition according to claim 1, characterized in that it additionally comprises sulfides.

3. Composition according to claim 1 or 2, characterized in that it additionally comprises organic substances.

4. Composition according to any one of claims 1 to 3, characterized in that the non-white clay minerals are original chloritic-illitic, chloritic-vermiculitic and / or kao I in itic-i 11 itic clays and / or bentonites.

5. Composition according to any one of claims 1 to 4, characterized in that the non-white clays are exclusively chloritic-illitic clays.

6. Composition according to any one of claims 1 to 5, characterized in that the fragrances are conifer fragrances, in particular fir needle extracts.

7. Composition according to any one of claims 1 to 6, characterized in that the fragrances are camphene, camphor and / or limonene or comprise these substances.

8. Composition according to any one of claims 2 to 7, characterized in that the sulfides are pyrite and marcasite.

9. Composition according to any one of claims 3 to 8, characterized in that the organic substances are humic substances and / or humic acids or fulvic acids.

10. Composition according to any one of claims 1 to 9, characterized in that the composition comprises water as its main component. 1 1 . Means according to claim 10 in the form of a spray suspension.

12. Composition according to claim 10 or 11, characterized in that the composition contains the non-white clay minerals in a quantity of 1 to 5% by weight, based on the finished spray suspension. Use of an agent according to any one of claims 1 to 12 as a repellent for psilocybin spiders. A method for controlling psilocybin spiders, characterized in that an agent according to any one of claims 1 to 12 is applied to the infested or potentially infested substrates. A method for producing an agent according to any one of claims 1 to 12 by mixing the ingredients in the desired mixture. Weight ratio.

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