A germination-promoting microencapsulated seed dressing and soil disinfectant composition with a biodegradable wall, comprising a pyrethroid active ingredient

Abstract

The invention relates to a microencapsulated insecticidal seed dressing or soil disinfectant composition comprising a pyrethroid - typically Tefluthrin or Cypermethrin - as an active ingredient, which has a germination-promoting effect due to the wall and its excipients, and the capsule wall degrades under the influence of the microbiological system of the soil and does not form microplastics.

Description

[0001] A germination-promoting microencapsulated seed dressing and soil disinfectant composition with a biodegradable wall, comprising a pyrethroid active ingredient

[0002] The invention relates to a microencapsulated insecticidal seed dressing or soil disinfectant composition comprising a pyrethroid - typically Tefluthrin of formula (I) or Cypermethrin of formula (II) - as an active ingredient, which has a germination-promoting effect due to the wall and its excipients, and the capsule wall degrades under the influence of the microbiological system of the soil and does not form microplastics.

[0003] The seed dressing or soil disinfectant composition according to the invention can be used to treat the seeds of important cultivated plants, typically corn and sugar beet, or to carry out soil disinfection during their cultivation.

[0004] The seed dressing agent according to the invention significantly accelerates the development of the seedling in the first stage of the germination process, stimulates germination compared to undressed seeds and seeds treated with a conventional microencapsulated composition, producing a plant that is about 30% more developed, within 13 days of planting. The seedling is protected against soil-dwelling pests, has a more developed root crown, and has increased stress tolerance in the initial stages of its development, compared to plants grown from seeds treated with conventional agents.

[0005] The soil disinfectant composition according to the invention also provides protection during the development of plants planted in soil treated with it, and also has a stimulating effect on plant development.

[0006] In order to exert the appropriate effect, it is necessary for the active ingredient to be gradually released from the microcapsule as a result of the biodegradation of the capsule wall, and to exert its physiological and plant protection effect. The material of the capsule wall remains in the soil at the end of the process and is proven to be degraded there by the action of the microbiome. The capsule wall is formed by interfacial polymerization, according to the invention by means of a polycondensation reaction of a mono- or poly-diisocyanate and pectin as wall-forming materials. Interfacial polymerization itself has long been well known in the art as a microencapsulation process. / (Preparation of nano- and microspheres by polycondensation techniques. Arshady R.J Microencapsul. 1989 Jan-Mar;6(1):1-12. doi: 10.3109 / 02652048909019897. PMID: 2654352), (Beestman, G. W. (1996) Emerging Technology: The Bases For New Generations of Pesticide Formulation), (Pesticide Science 54, 394-400. Microencapsulation of pesticides by interfacial polymerisation utilising isocyanate or aminoplast chemistry. Scher, H.; Rodson, M.; Lee, K. S. (1998)), (Journal of Microencapsulation 32(1):1-15: Microencapsulation by interfacial polymerization: membrane formation and structure. (2014) Carole Perignon et al.) / Polyamide, polyurea, polyurethane microcapsule walls are traditionally produced by polycondensation reaction of diamines or diols with diisocyanates at an emulsion interface. The average particle size of the resulting, typically spherical particles is 0.2 pm to 100 pm.

[0007] The disadvantage of this method is that the polyamide (nylon), polyurea, polyurethane microcapsule wall produced in this way does not degrade in nature after the physical release of the active ingredient, but remains there permanently, thereby forming an undesirable microplastic. Due to its micro nature (0.01 pm to 0.1 pm), living organisms can take them up, thus this substance accumulates in them, causing irreversible damage. The elimination of this extremely harmful phenomenon has been on the Ell agenda for some time (COMMISSION REGULATION (EU) 2023 / 2055 (25 September 2023)).

[0008] According to one aspect of the present invention, it is aimed at eliminating the microplastic phenomenon during agricultural use. This is achieved by reacting one of the traditional wallforming components, mono- or poly-diisocyanate, with a naturally occurring partner, pectin (E440), which has not previously been used for this purpose. When the pectin used is used in excess (0.5-3.5% by weight), a part of it participates in the formation of the capsule wall, the unreacted pectin stabilizes the composition as an excipient and has a significant effect in the initial stage of development of the plant grown from the treated seed.

[0009] Pectin is mainly used in the food and pharmaceutical industries, but it is also used in significant quantities in the production of cosmetics and food supplements (Current Advancements in Pectin: Extraction, Properties and Multifunctional Applications Foods. 2022 Sep; 11 (17): 2683).

[0010] The name pectin refers to those substances that form a group of complex colloidal carbohydrates. They occur in plants and can be extracted therefrom, and comprise chain-like linked galacturon molecules (Nelson et. al. 1977): Pectins are classified into three main groups based on their structure and characteristic properties:

[0011] 1. Homogalacturan (HG) A linear polymer made up of D-galacturonic acid monomers linked together by a-1 ,4 linkages. The degree of esterification of galacturonic acid is 60-90%, typically methyl ester substitution.

[0012] 2. Rhamnogalacturonate I: The polysaccharide skeleton is built up by alternating rhamnose and galacturonic acid units, and to these, other uncharged monosaccharide components (a-(1-5)-L-arabinose and p-(1-4)-D-galactose) are attached.

[0013] 3. Rhamnogalacturonate II: The main skeleton consists of 8 to 10 galacturonic acid units, to which 12 different types of sugars can be attached with 20 different types of bonds.

[0014] Within the pectin chain, we distinguish so-called smooth regions, wherein mainly homogalacturonate is found, and branched parts, wherein typically rhamnogalacturonate units can be observed (Pectin: Progress in Molecular Biology and Translational Science, 2016).

[0015] The type of pectin used to form the capsule wall influences the structure of the resulting wall, which makes it possible to design the rate of release of the active ingredient. This is especially true when using modified pectins.

[0016] Taking into account economic and reproducibility aspects, we primarily used commercially available Herbstreith & Fox brand pectins with different degrees of esterification in our experiments, in amounts of 0.5% to 3.5%.

[0017] During the interfacial polymerization according to the invention, a diisocyanate-pectin copolymer capsule wall is formed, which, when introduced into the soil, decomposes into carbon dioxide and other useful components under the influence of the microbiome there, and does not accumulate in the soil.

[0018] The use of polysaccharides, including pectin, for the creation of microcapsule walls has already been discussed before. The patent specifications that describe this process are fundamentally not aimed at agricultural use, and do not provide any examples of seed dressing or soil disinfection / (US Pat. No.10188593 B2 Microparticles prepared with polysaccharides), (WO 2015 / 0164117 A1 , US. Pat. No.4138362: Microcapsules prepared with natural materials such as chitosan).

[0019] For example, PCT / US2019 / 066844 describes the use of polysaccharides, including pectin, for the production of microencapsulated products, however, this applies exclusively to consumer products, during the production of which fragrances are encapsulated. The aim of the process in this case is to form a wall structure with appropriate permeability, in which in each case polydiisocyanate is one of the wall-forming components, the other is mostly polyphenol (tannic acid) and a polysaccharide, including pectin in some embodiments. Polysaccharides (pectin, xanthan) only participate to a small extent in the formation of the wall structure, they play a significant role in creating a stable composition form.

[0020] W02020 / 209908 (Consumer product with controlled release core-shell microcapsule compositions) lists wall-forming components of biological origin - polysaccharides, polypeptides, etc. - which are used to produce microcapsule suspensions with biodegradable wall, for the production of consumer products. Accordingly, the biostimulant effect on plants and the capsule wall-degrading effect of soil microelements cannot even arise in them.

[0021] WO2022 / 132056 describes the production of a biodegradable capsule wall, which is produced by interfacial polymerization. Toluene diisocyanate (TDI), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and paraffin oil are used to form the wall. According to the description, in the condensation wall-forming reaction, a basically polyurethane-polyurea type wall structure is formed, which is slightly modified. It does not mention the use of pectin, nor does it prove that the wall structure thus created is biodegradable. In the examples, it provides a gelatin wall formation by a coacervation process.

[0022] The cited patent specifications do not cover the possibility of agricultural application, do not list the production of insecticidal seed dressing or soil disinfectant compositions, in particular those comprising tefluthrin of formula (I) or cypermethrin of formula (II), nor the beneficial effect on plant development.

[0023] The active ingredient Tefluthrin is currently used in plant protection in microencapsulated form (WO2001 / 094001 SYNGENTA Ltd.). The microencapsulated Tefluthrin composition disclosed in the description was prepared (see Example 21) and used as a control in our experiments.

[0024] There was a demand from agricultural users for an effective insecticidal seed dressing agent. Tefluthrin proved to be the most suitable active ingredient for this purpose, given that its vapor pressure at 25°C is 8x1 O'3Pa, which is the highest value among synthetic pyrethroid derivatives. The vapor pressure of Cypermethrin at 25°C is 6x1 O'7Pa, which is four orders of magnitude lower than that of Tefluthrin, but is still significant.

[0025] Tefluthrin is also the most effective against soil-dwelling pests because it can migrate in the soil as a vapor, while not binding irreversibly to soil particles, like most pyrethroid derivatives (McDonald, E.; Punja, N.; Jutsum, A. R. (1986). "Rationale in the invention and optimization of tefluthrin, a pyrethroid for use in soil". British Crop Protection Conference- Pests and Diseases, Proceedings (1): 199-206).

[0026] Tefluthrin and Cypermethrin preferably can be used as soil disinfectants and seed dressing agents because they are volatile. However, their use, especially in the case of Tefluthrin, is limited by the strong skin irritation effect. Accordingly, it was obvious to use the active ingredient in microencapsulated form, which thus also has the additional advantageous properties of microencapsulated compositions. The envelopment of the active ingredient allows personnel who have become sensitive to the active ingredient to apply the substance directly.

[0027] In the known compositions comprising the active ingredient Tefluthrin, Tefluthrin is present in a conventionally produced microcapsule with a polyamide-polyurethane wall and thus forms a persistent microplastic in the soil after the active ingredient is released.

[0028] Accordingly, when using conventionally produced compositions, the biostimulant effect on plants and the capsule wall degrading effect of soil microelements do not occur at all.

[0029] In the compositions according to the invention, the conventional microencapsulation process was modified so that pectin was used as a wall-forming material for the condensation reaction of diisocyanate for wall formation, which, in addition to providing a proven biodegradable wall structure, also has a biostimulant effect.

[0030] Based on the above, the present invention relates to a microencapsulated, biodegradable seed dressing and / or soil disinfectant composition comprising a pyrethroid active ingredient, which comprises a capsule wall formed by interfacial polymerization of mono- or poly-isocyanate and pectin, and a biostimulant excipient.

[0031] Brief description of the figures:

[0032] Figure 1 : Enzymatic degradation of pectin (ester) into glucose and galacturonic acid.

[0033] Figure 2: Enzymatic degradation of biodegradable wall into glucose and galacturonic acid.

[0034] Figure 3: Investigation of the degradation kinetics of pectin and wall sample under the influence of an enzyme. Figure 4: Scale-up degradation kinetics investigation in the case of an enzyme-treated wall sample.

[0035] Figure 5: Investigation of the degradation kinetics of enzyme-treated pectin (ester), wherein galacturonic acid can be detected.

[0036] Figure 6: Investigation of the degradation kinetics of an untreated wall sample (in the case of pectin ester not treated with enzyme, the formation of galacturonic acid cannot be detected).

[0037] Figure 7: Kinetics of the biodegradation of a microcapsule wall comprising pectin.

[0038] Figure 8: Comparative study of root crown development in a small-plot corn plantation.

[0039] Figure 9: Comparative study of the germination of corn seeds dressed with a conventional and a biodegradable composition.

[0040] Detailed description of the invention

[0041] For the preparation of the seed dressing or soil disinfectant composition according to the invention, 1-50% by weight of Tefluthrin or Cypermethrin is preferably used as the pyrethroid active ingredient; homogalacturonate (HG), Rhamnogalacturonate I or Rhamnogalacturonate II is used as the pectin; 4,4'-phenylmethane diisocyanate (MDI) in monomer or polymer form, polymethylene polyphenylene diisocyanate (PAPI), or toluene diisocyanate isomers (TDI) is / are used as the diisocyanate component.

[0042] The composition according to the invention may further contain commonly used excipients, such as emulsifiers and suspending agents, such as ionic or non-ionic surfactants, as well as stabilizers, antifreeze agents.

[0043] The composition according to the invention comprises pectin used in excess of the amount of pectin necessary for forming the capsule wall, as a biostimulant excipient. To ensure simultaneous wall formation and stimulation functions, the concentration of pectin in the final product composition should preferably be kept at 1.2% to 3% by weight (w%).

[0044] It is known that mono-, di-, and polysaccharides are able to enter into a condensation reaction with isocyanates, creating a so-called sugar-based polyurethane structure (Molecular Design of Sugar-Based Polyurethanes Croat. Chem. Acta 2018, 91 (3), 299-307, Published online: June 30, 2018). However, there is no known publication that would prove that the sugar molecule incorporated into the polymer wall is degradable in nature.

[0045] Given that this is an essential issue from the point of view of use, the actual degradability was experimentally proven.

[0046] In the composition according to the invention, the tendency of the capsule wall to degrade was examined under laboratory conditions using two methods. First, we subjected the wall material to enzymatic treatment, and we found that the specific enzyme used for this completely degraded the wall material under the experimental conditions. No enzyme inhibitory effect was observed during the process.

[0047] For the experiments, we produced a wall material free of active ingredient, solvent and excipient by carrying out the condensation reaction with the wall-forming components in a targeted manner. (Example 16; production of wall material). We confirmed by particle analysis that the obtained material falls within a particle size range that corresponds to the average size range of the capsule comprising the active ingredient (average particle size: 3-5 pm).

[0048] The essence of the experiment was to prove in a comparative study that the wall material according to the invention, similarly to pectin (pectin ester), decomposes into glucose and galacturonic acid in the presence of pectinase enzyme. The study was carried out in two 50 mL stirred Schott bottles. In these, 0.16 g of dry wall material (MK 160) or pectin ester was mixed in 20 mL of distilled water each. The system was thermostated to 35°C by stirring and then 0.015-0.015g of pectinase enzyme was added to the vessels. At the start, a 1mL sample was taken from each vessel and frozen. After two days, they were sampled again. After that, the starting materials, their decomposition and its products (galacturonic acid) were detected using an HPLC method suitable for detecting sugars (Waters Breeze, isocratic system, BioradAminex HPX87H) (Figures 1 and 2).

[0049] Figure 1 shows that in the case of samples taken at time zero, the presence of standard pectin (pectin ester) and a small amount of galacturonic acid were detectable; according to Figure 2, due to the high molecular weight of the pectin-containing wall (MK-160), only a small amount of galacturonic acid was measurable at the very beginning of the process. In the second samples, taken and tested after 46 hours, the peak area of the pectin ester decreased significantly, while galacturonic acid increased significantly and glucose to a lesser extent, the latter two being the products of pectin degradation. Similarly, in Figure 2, a significant increase in galacturonic acid was observed in the 46-hour sample, i.e. the pectin degradation product also appeared in the case of the pectin-containing wall.

[0050] The enzymatic degradation of the wall sample was examined in larger quantities and over a longer period of time, in a similar manner to the previous experiment. 1g of pectin ester (control) and 1-1 g of pectin-containing wall sample (MK187) were dissolved in 100-100- 100mL of distilled water, then 0.2-0.2g of Pectinase enzyme (approx. 10Ounit, Sigma P2401- 500un) was added to the control and to one of the wall samples. The samples taken regularly were analyzed for galacturonic acid (pectin degradation product) using the HPLC method described above (Figure 3). Figure 3 shows that the reference pectin (PE) was degraded relatively quickly and completely to galacturonic acid upon enzymatic treatment. In the case of the enzyme- treated wall sample (ME), the degradation process was similar to that of pectin. Here, however, the amount of pectin incorporated into the wall is much smaller compared to pure pectin, thus the amount of galacturonic acid produced during the degradation is also smaller. In the case of the control (M), i.e. the untreated wall sample, we did not detect the galacturonic acid degradation product.

[0051] Based on the above experiment, the kinetic measurement was performed at a fivefold increased concentration. For the experiment, 1g of pectin ester and 1-1 g of pectin-containing wall material were measured into 20-20-20 mL of distilled water. 0.2-0.2 g of Pectinase enzyme was added to the pectin ester and to one of the pectin-containing wall materials, and no enzyme was added to the other pectin-containing wall material. The samples were stirred at a room temperature of 30°C and then analyzed by HPLC method as described above.

[0052] As shown in Figure 5, the reference pectin degradation was successful, the time function of galacturonic acid almost tends to saturation. Figure 4 shows that the degradation of the pectin- containing wall was also successful, and in fact, an alcohol-producing fungus grew on the formed galacturonic acid under anaerobic conditions and converted the galacturonic acid into alcohol. It is clear that in the first 50 hours, the wall breaks down into galacturonic acid (gray curve), after which ethanol is formed from the produced galacturonic acid (black curve). In the sample taken after 200 hours, there was hardly any galacturonic acid, and the ethanol peak has reached a maximum. Neither galacturonic acid nor anything else was released from the wall without the enzyme (Figure 6). As shown in Figure 5, in the case of the pectin ester treated with the enzyme, only the formation of galacturonic acid was detected. Here, the decomposition reaction did not proceed further to alcohol.

[0053] The control, i.e. the untreated wall sample, did not degrade, as shown in Figure 6.

[0054] Based on the experiment, we received quality confirmation that a specific enzyme can successfully degrade the pectin chain chemically incorporated in the capsule wall, thereby fragmenting the cross-linked structure of the capsule wall.

[0055] Following the successful enzymatic degradation of the pectin-containing capsule wall, we ascertained that this chemically produced cross-linked structure can also be considered a substrate for biological systems occurring in nature, in soil, primarily for fungi, they are able to degrade the wall material. This was confirmed by a compostability test.

[0056] For the experiment, we used a wall material produced as described above, following the specifications of the ISO 14855-1 - ultimate aerobic biodegradation of plastic materials under controlled composting conditions standard. The WTW OxiTop system was used to test the samples, following both the manufacturer’s and the standard’s specifications as described in the following chapter.

[0057] The activity of the degradation processes of the samples was tested in a WTW OxiTop soil respirometer. The measurement is based on the oxygen consumption of microorganisms and the simultaneous production of carbon dioxide. In a closed system, the carbon dioxide produced is absorbed by a sodium hydroxide adsorbent, thereby creating a micro vacuum in the measuring vessel. The OxiTop - type C measuring head connected to the measuring vessel records this pressure change. The data can be retrieved with the OC 110 type controller suitable for this purpose and can then be displayed in a table or even in a diagram as desired.

[0058] In the case of long-term experiments, it must be taken into account that the amount of oxygen available in the closed measuring vessel is not unlimited. Therefore, in such cases - taking into account the amount and origin of the sample - it is necessary to aerate the vessels. The air replenishment was carried out every 3 days, for 1 hour, maintaining the original temperature of the experiment and together with the replacement of the adsorbent. Immediately after the air replenishment, the current atmospheric pressure is restored in the system, and the vacuum formation starts again. The interventions are registered by the controller and taken into account when calculating the pressure change curve.

[0059] We used compost potting soil from retail trade as the basic matrix. After drying to a moisture content of 20%, 70 g of this compost was measured into each experimental vessel. After that, 4.6 grams of cellulose powder were added to the vessels marked TM I. to IV., 4.6 grams of experimental material “A” to the vessels marked A I. to IV., and 4.6 g of experimental material “B” to the vessels marked B I. to IV., and a Blank (negative control) sample that did not receive any supplementation was also set up, similarly in four replicates (Blank I. to IV.). After mixing and homogenization, the matrices were moistened with 30 mL of distilled water in each vessel.

[0060] In accordance with the MSZ EN ISO 14855-1 standard, the OxiTop vessels were sealed and then incubated at 50°C for the entire duration of the experiment. The pressure change in the vessels could be monitored daily.

[0061] After the first week, the processes in the closed system clearly reached a standstill, so that by the second week no significant respiration changes could be observed and registered. The standstill does not necessarily indicate that the amount of biodegradable materials in the system has run out, but rather it may indicate the occurrence of limiting factors. According to the standard, we would have maintained the system for 40 days, but from the second week to the fourth week (28 days) there was no change in the respiration values, despite aeration. For this reason, we dismantled the systems after 28 days and dried the contents of the vessels at 65°C until constant weight. After the test, the data from the OxiTop measuring heads were uploaded to a computer, and a summary graph illustrating the respiratory activity was created using the MS Excel program.

[0062] According to our tests, the degradation of the wall material occurred intensively, in an extremely short time, with the evolution of carbon dioxide. The evolution of carbon dioxide was more intense than in the case of the cellulose powder used as a control.

[0063] Based on the two experiments, we concluded that the diisocyanate-pectin copolymer wall material, when introduced into the soil as a seed dressing agent, decomposes there and does not accumulate.

[0064] The kinetics of the biodegradation of the pectin-containing microcapsule wall are illustrated in Figure 7:

[0065] “Blank” - only compost, without degradable material;

[0066] Group “A” - non-degradable capsule wall;

[0067] Group “TM” (Test material) - cellulose powder, a test material that degrades under given conditions;

[0068] Group “B” - microcapsule wall material synthesized with pectin.

[0069] From the point of view of the adequacy of the test results, it is important that the identical treatments have almost the same course, i.e. we did not observe any significant differences between the replicates. It is clearly visible from the respiration results that the “Blank” settings, comprising compost and water, reached constancy in respiration activity on the sixth day (144th hour).

[0070] It can be clearly seen in Figure 7 that the settings comprising the experimental sample “A” were also run in parallel with the “Blank” settings functioning as a control. The respiration values of the two settings (“Blank” and group “A”) almost overlap each other as can be seen in the figure.

[0071] The known biodegradable cellulose “TM” settings reached the respiration plateau already on the third day (approx. 72nd hour), i.e. despite the aeration, the degradation processes ran out of energy or other nutrients, which could limit biodegradation and respiration. The “TM” settings gave much steeper respiration values than the “Blank” and “A” settings, i.e. the biodegradation and the resulting respiration were much more intense in these vessels, as expected from the positive control. The vessels comprising the test sample “B” (group “B”) showed even more intense respiration activity than the “TM” setting. By the second day (approx. 48 hours), the respiration processes reached the plateau, i.e. the available energy or nutrients in the system were exhausted despite the aeration. The test sample “B” therefore decomposed more intensively than the proven biodegradable cellulose used as a positive control, which confirms the microbial degradability and compostability of the sample.

[0072] Based on the measured respiration values, it is clearly visible that, in case of the experimental sample “B”, a more intensive respiration activity and biodegradation can be measured than for the positive control (cellulose).

[0073] During the tests carried out in the OxiTop respiration system, out of the two tested samples (test samples “A” and “B”), in the case of the test sample “B” we were able to detect a more intensive respiration activity than the easily biodegradable cellulose used as a positive control, and we also measured a more intensive weight loss compared to the sample supplemented with cellulose (“TM”). In the case of the test sample “B”, the biodegradation of the sample “B” can be established under the test conditions based on the respiration test and the weight measurements. Thus, based on our preliminary test results, the sample marked “B” is bioavailable, microbially degradable and compostable.

[0074] The microencapsulated composition comprising the active ingredient Tefluthrin or Cypermethrin according to the invention, which is produced by interfacial polymerization, has an additional advantageous property that, due to its adjuvant effect, it exerts a positive physiological effect in the initial stage of development of the plant grown from the seed. The composition thus produced, given its significant biological benefits, is also an excellent soil disinfectant and seed dressing agent. The biological effectiveness of the microcapsule suspension composition - said microcapsule having a proven degradable wall - as a seed dressing agent, applied to corn, was verified in a small-plot experiment.

[0075] A small-plot field trial was conducted, using a biodegradable composition at a concentration of 200; 250; 300 rnL / U sowing unit (1 sowing unit = 100 thousand seeds) as a corn seed dressing agent. Undressed corn seed was used as a control, and Tefluthrin 1.5 G soil disinfectant granules were used as a reference.

[0076] The treatments were randomized in 4 replicates, with a plot size of 338 m2. The seed dressing agent was applied to the seed the day before sowing.

[0077] The first control test was performed in the third month after sowing, in the middle of the flowering period. The roots of 20 randomly selected corn plants per plot were examined and classified according to the IOWA scale (0 to 6). During the evaluation, the economic threshold value was determined at 3.5 on the IOWA scale. The damage caused by corn rootworm in the tested treatments was below the threshold value. The effect of the biodegradable compositions reached the standard level and far exceeded that of the control. (Figure 8) We compared the development of plants grown from seeds treated with the same dose of conventional Tefluthrin-containing seed dressing agent (Cult-Tef 20 CS) (Example 21) and those treated with the biodegradable composition (Cult-Tef 20 CS BD) (Example 1) 3 months after planting. The results obtained are shown in Table 1. At both concentrations, the plant treated with the biodegradable composition showed a more favorable effect (by 5-10%) in the value measured according to the IOWA scale. Photos of the root systems clearly showed that the root systems of seeds treated with the pectin-containing seed dressing agent were stronger and more branched than those treated with the conventional treatment.

[0078] Table 1

[0079] Based on the test performed, the composition comprising the seed dressing agent according to the invention keeps the damage caused by root-damaging beetles below the damage threshold at all applied doses.

[0080] Against soil-dwelling pests, wireworms, and in the case of corn, the corn rootworm (Diabrotica spp.), the aqueous suspension of Tefluthrin microcapsules can be effectively used as a soil disinfectant or as a seed dressing agent. The efficacy tests conducted have proven that there is no difference in terms of efficacy between the two treatment technologies, and seed dressing provides similar protection against pests as soil disinfection.

[0081] However, the difference is very significant in terms of the chemical load on the soil and its economical application. In the case of soil disinfection, according to the currently used technology, 15 kg of granules are spread per hectare. The active ingredient content of the granules is 15 g / kg. In this way, 225 g of Tefluthrin active ingredient is applied per 1 hectare.

[0082] In the case of dressing, 1 sowing unit of seeds (1 U=100 thousand seeds) was treated with 300 mL of an aqueous suspension comprising 20% Tefluthrin. The weight of 1 II of seeds naturally varies from plant to plant. In the case of corn, the weight of 1 II is on average 25 kg, and the sowing rate is 0.8 U / hectare. In this way, in the case of seed dressing, 0.8x0.3x200 = 48 g of Tefluthrin active ingredient is applied per 1 hectare, guaranteeing the necessary biological effectiveness in order to protect the crop.

[0083] The biodegradable composition according to the invention is not only able to reduce the chemical load of the soil, but also, due to its degradable wall structure, does not leave behind microplastic pollution. Our composition with a biodegradable microcapsule wall, comprising the active ingredient Cypermethrin, was tested in a large-plot field trial. We tested its effectiveness against soil-dwelling pests, primarily larvae of click beetles (Elateridae), larvae of chafers (Melolonthinae), and larvae of Western corn rootworm (Diabrotica virgifera) in corn culture. The experimental plot size exceeded 5000 m2For the study, two microcapsule suspensions with different wall thicknesses, comprising the same 15% of Cypermethrin active ingredient (Cult-Cyp 15 CS A, Cult-Cyp 15 CS B) were used. Both samples were applied at three different doses (1 L / ha, 2 L / ha, 3 L / ha). An untreated plot, as well as the commercially available Force 1.5 G (15 kg / ha) Tefluthrin-containing microgranules and Belem 0.8 MG (12 kg / ha) Cypermethrin-containing microgranules, were used as controls. The compositions were applied to the soil in one pass with sowing in 4 parallel experiments.

[0084] One month after planting, it was determined that compared to the untreated control, the treatments with the tested Cult-Cyp 15 CS A and Cult-Cyp 15 CS B compositions at doses of 2.0 and 3.0 L / ha showed stronger stems and more vigorous development of the plants.

[0085] We obtained the same results when compared with the compositions used for control.

[0086] Another advantage of water-based microcapsule-containing soil disinfectant compositions is that they can be freely mixed with similarly water-based starter fertilizers.

[0087] In this way, soil disinfection and starter fertilizer application can be carried out in one technological phase at the same time as sowing.

[0088] In this case, the commercially available KITE Start Liquid NP at a dose of 20L / ha was used.

[0089] The effect on plants is clearly visible in case of treatments with Cult-Cyp 15 CS B 2.0 L / ha + KITE Start Liquid NP 20 L / ha.

[0090] The results of our tests with starter fertilizers show that the plant is provided with easily absorbed nutrients in the initial development of the plant (up to the 6-7 leaf stage, BBCH 06- 08).

[0091] By using Cult-Cyp 15 CS B and starter fertilizer together, in addition to the insecticidal effect, the additive, positive effect of the two products is achieved during the initial stage of seedling development. In a small-plot field trial, we compared the development of plants grown from sugar beet seeds treated with the conventional Tefluthrin 20 CS composition and from sugar beet seeds treated with the biodegradable Tefluthrin 20CS BD composition produced by us.

[0092] The plot size was 155 m2, the sowing time was April 24. The first evaluation date was in the first month after planting, which is the first period of sugar beet development, the so-called vegetative stage. In the case of sugar beet, the plant is well characterized by the green surface formed during this stage of development. One month after planting the seeds, the vegetation grown from seeds treated with the biodegradable composition had twice the green surface compared to the conventional one. This clearly demonstrated that the pectin-containing composition also has a biostimulant effect in the case of sugar beet in the initial stage of plant development, as well as in the generative stage, when the generative organs are formed. If the purpose of the cultivation is sugar production, the harvest takes place at the end of the first year, at the end of the vegetative phase. For the purpose of seed production, the direct cultivation method allows the seeds to be harvested at the end of the second year, at the end of the generative development stage.

[0093] The phenological phases and average dates of sugar beet are as follows:

[0094] • sowing - emergence, 15 March to 10 April

[0095] • emergence - beginning of intensive leaf formation, 10 April to 10 May

[0096] • intensive leaf formation - decortication (bark detachment) leaf formation, root thickening 10 May to 10 July

[0097] • decortication - tuberation, the phase of intensive sugar accumulation, 10 July to 1 October.

[0098] During the tests, we found that the biodegradable microcapsule suspension according to the invention, created with a pectin-diisocyanate wall, which also comprises pectin as a formulation excipient in addition to the wall structure, accelerated seed germination and seedling development.

[0099] The extent of the effect was tested under laboratory conditions.

[0100] 10 dressed corn seeds were placed on wet cotton wool in a Petri dish. Seeds treated with biodegradable microencapsulated composition were placed in a Petri dish labeled BD, and seeds treated with conventional microencapsulated Tefluthrin composition were placed in a Petri dish labeled Tef. The Petri dishes were kept in the dark for 4 days and kept moist. After that, the developing plants were kept under normal conditions, at the same temperature and moisture content. Within two weeks after germination, the BD seedling was 30% more developed than the seedling grown from seed sown without dressing, and the seedling grown from the seed treated with the conventional microencapsulated Tefluthrin seed dressing agent. The root system of the seedling grown from the seed treated with the pectin-containing Tefluthrin microencapsulated seed dressing agent produced by us became denser, and its stem was taller and thicker.

[0101] As a result, the plant has a better stress tolerance in the initial stages of its development. This can be especially significant in particularly dry periods.

[0102] The comparative study we conducted proves that pectin has a significant positive role in the development of the corn seed in the weeks following planting.

[0103] The experiment was repeated in soil. We planted 10-10 differently treated corn seeds in 4 pots with a diameter of 13 cm and a height of 11 cm. In the first case, seeds treated with conventional Tefluthrin 20 CS composition were used, and in the second case, seeds treated with biodegradable Tefluthrin 20 CS composition were used. Undressed seeds were planted in the third and fourth pots, with the difference that in the third case, the seeds were soaked in a 1.5% pectin solution overnight before planting. Untreated seeds in the fourth pot served as a control. The study was conducted for 13 days. The seeds planted in pots received the same amount of water, were stored at the same temperature and light conditions. Table 2 and Figure 9 clearly show the different development of the plants up to the 13th day after planting. The length of the plants grown from the ten seeds was measured and the average of the measured values is indicated in Table 2.

[0104] Table 2

[0105] Plants grown from undressed seeds and seeds treated with the conventional microencapsulated composition were less developed compared to corn grown from seeds treated with the composition produced according to the present patent and from seeds soaked in pectin. The difference between the samples is extremely significant. This developmental advantage, seen in the dressed sample, is caused by the high pectin content of the seed dressing agent used. This is confirmed by the fact that the developmental tendency of undressed, pectin-soaked seeds is similar to the microencapsulated composition comprising pectin.

[0106] The invention is illustrated by the following examples, without limiting the invention to the examples.

[0107] Examples

[0108] 1. Preparation of pectin solution: 5.6 g of pectin (Pectin Classic AF 703, Herbstreith&Fox GmbH) was measured into a 500 mL beaker. 300 mL of distilled water was added and it was stirred overnight at room temperature until the pectin was completely dissolved.

[0109] Tefluthrin 20 CS BD composition: 176 g of a 1.5% solution of pectin in distilled water and 3 g of MADEOL AG / OR 95 and 3 g of SUPRAGIL MNS / 90 detergents were measured into a 1000 mL beaker equipped with an IKA 18 Ultra-Turax mixer. The mixture was stirred at 9000 rpm. In parallel, 62 g of Tefluthrin and 9 g of Suprasec 5025 (CAS: 9016-87-9) isocyanate preparation were dissolved at 40-45°C in 58.1 g of Solvesso 200 solvent, then the resulting solution was poured into the aqueous solution. The mixture was stirred for 10 minutes at 10000 rpm, while 2 drops of Silfoam aqueous solution were added to reduce foaming. The speed was reduced to 4000 rpm. The composition was stabilized with a mixture of 1 g of xanthan and 1 g of TMP mixed in 16 g of propylene glycol. The stirring time was 5 minutes. The particle size distribution was measured with a Malvern laser particle analyzer.

[0110] The resulting 333.6 g of product was used directly.

[0111] The characteristics of the Tefluthrin 20 CS BD composition prepared according to Example 1 are summarized in Table 3.

[0112]

[0113] Table 3

[0114] 2. We proceeded as in Example 1 , except that Aromatol was used as the solvent instead of Solvesso 200. Average particle size: 6.84 micrometers.

[0115] 3. We proceeded as in Example 1 , except that instead of Classic Pectin AF 703, we used Pectin Classic AU 202. Average particle size: 5.6 micrometers.

[0116] 4. We proceeded as in Example 1 , except that instead of Classic Pectin, we used Pectin Classic AU 701. Average particle size: 4.18 micrometers.

[0117] 5. We proceeded as in Example 1 , except that instead of a 1.5% Pectin solution, we used 176 g of a 2% Classic Pectin solution. The amount of xanthan in the composition was reduced by half. Average particle size: 4.46 micrometers.

[0118] 6. We proceeded as in Example 1 , except that instead of Suprasec 5025, we used 9 g of Ongronat 2030 isocyanate component. Average particle size: 7.46 micrometers.

[0119] 7. We proceeded as in Example 1 , except that instead of Madeol and Supragil, 3.66 g of Dispersogen 1498 and 7.2 g of Atloxwere added as emulsifiers to 170 g of 1.5% pectin solution. The particle size distribution of the Tefluthrin 20 CS BD composition prepared according to Example 7 is summarized in Table 4.

[0120] Table 4 8. We proceeded as in Example 7, except that 7.2 g of Supragil and 3.66 g of Atlox were used as emulsifiers. The particle size distribution of the Tefluthrin 20 CS BD composition prepared according to Example 8 is summarized in Table 5.

[0121] Table 5 9. 179 g of a 1.5% solution of Pectin Classic AF 703 in distilled water, as well as 3.6 g of

[0122] MADEOL AG / OR 95 and 11.25 g of EMULGANTE NIO-X emulsifier excipients were measured into a 1000 mL beaker equipped with an IKA 18 Ultra-Turax mixer. The mixture was stirred at 9000 rpm. In parallel, 62 g of Tefluthrin and 6.5 g of SUPRASEC 5025 (MDI) were dissolved at 40-45°C in 31.5 g of Solvesso 200 solvent, then the resulting solution was poured into the aqueous solution. The mixture was stirred for 6 minutes, while 2 drops of Silfoam aqueous solution were added to reduce foaming. The speed was reduced to 4000 rpm. A mixture of 4 g of monoethylene glycol, 1.45 g of glycerol, 0.75 g of xanthan and 0.6 g of TMP was added to the resulting emulsion.

[0123] The resulting 300 g of product was used directly. Average particle size: 3.89 micrometers. The characteristics of the Tefluthrin 20 CS BD composition prepared according to Example 9 are summarized in Table 6.

[0124] Table 6 10. 14.5 g of a 1.5% solution of Pectin Classic AF 703 in distilled water, as well as 0.3 g of MADEOL AG / OR 95 and 0.93 g of EMULGANTE NIO-X emulsifier excipients were measured into a 150 mL beaker equipped with an IKA 18 Ultra-Turax mixer. The mixture was stirred at 9000 rpm. In parallel, 4.9 g of Tefluthrin and 0.55 g of 4,4’-dimethylphenyl isocyanate (Alfa Aesar, 98% Monomer MDI) were dissolved at 55-60°C in 7 g of Solvesso 200 solvent, then the resulting solution was poured into the aqueous solution. The mixture was stirred for 6-8 minutes at 9000 rpm. The speed was reduced to 4000 rpm. A mixture of 0.54 g of propylene glycol, 0.05 g of xanthan and 0.04 g of TMP was added to the resulting emulsion.

[0125] The resulting 28.5 g of product was used directly. Average particle size: 3.23 micrometers.

[0126] 11. We proceeded as in Example 10, except that instead of the 1.5% Pectin Classic AF 703 solution, a 1.5% Pectin Classic AU 202 solution was used. Average particle size: 4.51 micrometers.

[0127] 12. We proceeded as in Example 10, except that instead of the 1.5% Pectin Classic AF 703 solution, a 1.5% Pectin Classic AU 701 solution was used. Average particle size: 3.87 micrometers. Average particle size: 4.18 micrometers.

[0128] 13. 28.4 g of a 1.5% solution of Pectin Classic AF 703 in distilled water, as well as 0.6 g of MADEOL AG / OR 95 and 1.8 g of EMULGANTE NIO-X emulsifier excipients were measured into a 150 mL beaker equipped with an IKA 18 Ultra-Turax mixer. The mixture was stirred at 9000 rpm. In parallel, 10 g of Cypermethrin and 1 g of diisocyanate (Suprasec 5025) were dissolved at 40-45°C in 5.2 g of Solvesso 200 solvent, then the resulting solution was poured into the aqueous solution. The mixture was stirred for 6-8 minutes at 9000 rpm. The speed was reduced to 4000 rpm. A mixture of 0.06 g of xanthan and 0.04 g of TMP (1 ,1 ,1- tris(hydroxymethyl) propane) mixed in 1 g of propylene glycol was added to the resulting emulsion.

[0129] The resulting 44.5 g of product was used directly. Average particle size: 5.11 micrometers.

[0130] 14. We proceeded as in Example 13, except that 28.4 g of Pectin Classic AU 202 solution was used as the pectin solution. The resulting 44.5 g of product was used directly. Average particle size: 3.87 micrometers.

[0131] 15. We proceeded as in Example 13, except that 28.4 g of Pectin Classic AU 701 solution was used as the pectin solution. The resulting 44.5 g of product was used directly. Average particle size: 3.12 micrometers.

[0132] 16. Preparation of biodegradable wall: 7 g of Suprasec 5025 isocyanate preparation was measured into a 50 mL beaker. It was dissolved in 40 mL of methylene chloride at room temperature. 100 mL of 2% pectin solution was measured into a 250 mL beaker and stirred with an ultra-turax mixer at 9000 rpm. The methylene chloride solution was added to the aqueous solution, then the stirring was maintained for another 10 minutes. After that, it was stirred overnight at room temperature with a KPG mixer at 550 rpm. In the morning, the solvent- free suspension was filtered and washed with 3x150 mL of distilled water. The resulting powdery material was dried and ground. Its particle size was verified with an analyzer. Average particle size: 3.8 micrometers. The resulting 8 g of product was used for biodegradability tests.

[0133] 17. Dressing of corn seeds with biodegradable composition: 111 g of corn seeds are measured into a flask of a Rotadest apparatus, to which 2.42 g of Tefluthrin 20 CSBD composition and 2.5 mL of water mixed with 0.035 g of Methocel and 0.1 g of red dye are added. In order to evenly coat the seeds, the flask is rotated at low speed for 1 hour at room temperature. After that, they are dried at room temperature. If used directly, drying is not necessary.

[0134] 18. Dressing of corn seeds with a conventional composition (control): We proceed as in Example 17, except that the Tefluthrin 20 CS conventional seed dressing agent is used for coating the seeds.

[0135] 19. Dressing of sugar beet seeds with biodegradable composition: We proceed as in Example 17, except that sugar beet seeds are used instead of corn seeds.

[0136] 20. Dressing of sugar beet seeds with a conventional composition (control): We proceed as in Example 18, except that sugar beet seeds are used for the seed dressing.

[0137] 21. Preparation of Tefluthrin 20 CS conventional composition (control):

[0138] In a 250 mL beaker, 62 g of Tefluthrin active ingredient was dissolved at 40°C in 58.1 g of Solvesso 200 solvent, and then 9 g of Ongronat 2100 poly-diisocyanate preparation was added.

[0139] 176 g of 0.25% polyvinyl alcohol solution, 3 g of MADEOL-AG-OR / 96 and 3 g of SUPRAGIL MNS / 90 detergents were measured into a 1000 mL beaker, which was equipped with an Ultra- Turax mixer. The resulting solution was stirred at 8000 rpm and cooled to 5°C with ice water. After that, the organic phase previously prepared was slowly added to the aqueous phase. To reduce foaming, a little SILFOAM aqueous solution was added to the system. The postreaction was 6 minutes. The speed was set to 5000 rpm, then 1.5 g of 1 ,6-hexanediamine 40% aqueous solution was added to the system. After another 5 minutes of stirring, the composition was stabilized with 1 g of xanthan and 16 g of propylene glycol.

[0140] The amount of the resulting product: 298.8 g, average particle diameter 8.4 micrometers.

[0141] 22. Preparation of Cypermethrin 15 CS biodegradable composition (soil disinfectant Cult-Cyp 15 CS A): In a 500 mL beaker, 154 g of Cypermethrin active ingredient was dissolved at 40°C in 70 g of Solvesso 200 solvent, and then 20 g of Suprasec 5025 diphenylmethane diisocyanate preparation was added.

[0142] 680 g of 1 % Pectin (Pectin Classic AU 202, Herbstreith & Fox GmbH) solution, 13.5 g of MADEOL-AG-OR / 96 and 32 g of EMULGIN B25 (Sigma-Aldrich) detergents and 0.1 g of Mirecide -KW / 600.X biocide preservative were measured into a 1500 mL beaker, which was equipped with an Ultra-Turax mixer. The resulting solution was stirred at 7000 rpm and cooled to 15°C with ice water. After that, the organic phase previously prepared was slowly added to the aqueous phase. To reduce foaming, a little SILFOAM aqueous solution was added to the system. The post-reaction was 6 minutes. The speed was set to 5000 rpm and after another 5 minutes of stirring, the composition was stabilized with 0.45 g of xanthan and 19.3 g of propylene glycol.

[0143] The amount of the resulting product: 975 g, average particle diameter 4.6 micrometers.

[0144] 23. Preparation of Cypermethrin 15 CS biodegradable composition (soil disinfectant Cult-Cyp 15 CS B):

[0145] We proceeded as in Example 22, except that instead of 20 g of SUPRESEC 5025, 31 g of SUPRASEC 5025 diphenylmethane diisocyanate was measured when measuring the organic phase. The resulting 987 g of product was used directly. Average particle size: 4.75 micrometers.

Claims

Claims1. Microencapsulated, biodegradable seed dressing and / or soil disinfectant composition comprising a pyrethroid active ingredient, which comprises a capsule wall formed by interfacial polymerization of mono- or poly-isocyanate and pectin, and a biostimulant excipient.

2. The seed dressing and / or soil disinfectant composition according to claim 1 , characterized in that it comprises Tefluthrin as the pyrethroid active ingredient in an amount of 1-50% by weight.

3. The seed dressing and / or soil disinfectant composition according to claim 1 , characterized in that it comprises Cypermethrin as the pyrethroid active ingredient in an amount of 1-50% by weight.

4. The seed dressing and / or soil disinfectant composition according to any one of claims 1 to3, characterized in that the pectin is homogalacturonate (HG), or Rhamnogalacturonate I, or Rhamnogalacturonate II type pectin.

5. The seed dressing and / or soil disinfectant composition according to any one of claims 1 to4, characterized in that the mono- or poly-isocyanate is 4,4'-phenylmethane diisocyanate (M DI) in monomer or polymer form, or polymethylene polyphenylene diisocyanate (PAPI), or toluene diisocyanate isomer (TDI).

6. The seed dressing and / or soil disinfectant composition according to any one of claims 1 to5, characterized in that it further comprises one or more excipients selected from emulsifiers and suspending agents - such as ionic or non-ionic surfactants -, stabilizers, antifreeze agents.

7. The seed dressing and / or soil disinfectant composition according to any one of claims 1 to6, characterized in that it comprises pectin used in excess of the amount of pectin necessary for forming the capsule wall, as a biostimulant excipient.

8. The seed dressing and / or soil disinfectant composition according to claim 7, characterized in that the total amount of pectin in the product for simultaneously forming the capsule wall and providing the biostimulant excipient functions is preferably 1.2% to 3% by weight.

9. Use of the composition according to any one of claims 1 to 8 for treating corn seeds.

10. Use of the composition according to any one of claims 1 to 8 for treating sugar beet seeds.

11. Use of the composition according to any one of claims 1 to 8 as a soil disinfectant.

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