Composition for the treatment of pests of the olive tree plant

Abstract

The composition for the treatment of pests of the olive tree plant comprises an aqueous dispersion comprising one or more cupric compounds, one or more alkaline-earth metal hydroxides, one or more dispersing agents and one or more defoaming agents.

Description

[0001] COMPOSITION FOR THE TREATMENT OF PESTS OF THE OLIVE TREE PLANT

[0002] Technical Field

[0003] The present invention relates to a composition for the treatment of pests of the olive tree plant, particularly for the treatment of the Bactrocera oleae pest.

[0004] Background Art

[0005] The olive fruit fly, Bactrocera oleae, is an insect belonging to the subfamily Dacinae (Munro, 1984).

[0006] It is a fruit-eating species, the larvae of which bore tunnels into the olive fruits. It is considered the most serious pest of the olive tree plant.

[0007] Female B. oleae lay eggs starting in late July (depending on the region), when the olive has a diameter of at least 7-8 mm.

[0008] The eggs are laid by piercing the olive’s skin with the ovipositor and depositing a single egg in the cavity below.

[0009] The egg hatches after a period that varies, depending on weather conditions, from 2-3 days in summer to about 10 days in autumn.

[0010] The newly hatched larva initially burrows a tunnel near the surface but then moves deeper into the flesh until it reaches the pit. During larval development, two molts occur, resulting in an increase in the larva’s size. Around the third molt, the third-instar larva moves toward the surface and prepares the exit hole for the adult, gnawing the flesh until only a very thin surface layer remains. At this stage, the olive tree plant clearly shows signs of the attack because it appears darker around the perforation. A translucent circular hole is visible on the surface due to the remaining skin. The pupa remains dormant in the cavity below, protected and enclosed within the pupal case formed by the exuviae of the mature larva.

[0011] Upon reaching maturity, the adult breaks through the pupa’s exuviae and emerges from the pupal case.

[0012] It forcefully breaks through the cuticle left by the larva, leaving the exit hole. In late autumn and winter, its behavior changes: the mature larva emerges from the olive tree plant and falls to the ground, where it transforms into a pupa.

[0013] Adults feed primarily on honeydew.Since their basic diet is low in protein, they are particularly attracted to materials that emit volatile nitrogenous substances, such as bird droppings, to supplement their protein requirements.

[0014] The damage caused by the olive fruit fly can be of three types:

[0015] Destruction of the fruit pulp;

[0016] Drop of infested fruit;

[0017] Deterioration of the quality of the olives and of the oil.

[0018] The first problem is less serious since pulp loss ranges from 3 to 5%.

[0019] Olive drop is undoubtedly the most significant damage caused by the olive fruit fly, since it can affect a substantial portion of the crop, which cannot be used. Finally, the infestation causes a series of biochemical changes in the olive due to the presence of oxygen that enters the fruit through the exit hole made by the larva.

[0020] The most well-known effect is an increase in acidity, i.e., the percentage of free fatty acids.

[0021] The aforementioned damage caused by the olive fruit fly can vary in severity depending on seasonal conditions, olive variety, plant condition, exposure, and soil location.

[0022] Several methods are known in the art for reducing and / or preventing the damage caused by the olive fruit fly.

[0023] A first technique is based on preventive treatment (adulticide) involving repeated, localized distribution of protein baits laced with insecticides.

[0024] This technique involves the massive use of broad-spectrum insecticides that do not take beneficial insects into account.

[0025] Furthermore, their high toxicity will likely lead to their ban and / or replacement in the near future.

[0026] A second technique is based on curative treatment (larvicide), which involves applying insecticide mixtures to the entire foliage when the infestation threshold is reached (approximately 1-2% of the fruit affected).

[0027] The most commonly used active ingredient is dimethoate, a synthetic organophosphate insecticide, also preferred for its high solubility in water and systemic action within the fruit.The widespread, and at times excessive, use of this product has led to a reevaluation of its application, particularly in fruit growing.

[0028] Restrictive measures are expected in the near future for the entire olive sector, not only in Italy but also at the European level.

[0029] A third technique is organic treatment, which involves the mass capture of adult B. oleae using traps baited with various substances, such as hydrolyzed proteins or ammonium salts (for capturing females) and pheromones (for capturing males).

[0030] These traps contain insecticides at varying concentrations, e.g. dimethoate. This method is not always feasible due to the size of the plants and their dense foliage, which would require the use of a large number of traps, resulting in excessive costs. Furthermore, this technique must be supplemented with other methods to enhance its effectiveness, such as insecticide treatments across the entire foliage, especially in years when the infestation is particularly severe. To fight against the olive fruit fly, there is therefore a need for new products that are more effective, longer-lasting on the plant, and less polluting to the soil and water.

[0031] Description of the Invention

[0032] The main aim of the present invention is to devise a composition for the treatment of pests of olive tree plants that can be applied homogeneously and evenly onto the plant.

[0033] Another object of the present invention is to devise a composition for the treatment of pests of olive tree plants that allows for practical and effective distribution.

[0034] Another object of the present invention is to provide a composition for the treatment of pests of olive tree plants that allows the aforementioned drawbacks of the prior art to be overcome, offering a simple, rational, easy and effective to use, as well as cost-effective solution.

[0035] The aforementioned objects are achieved by the present composition for the treatment of pests of olive tree plants having the characteristics of claim 1.

[0036] Embodiments of the Invention

[0037] The present invention relates to a composition for the treatment of pests of olivetree plants.

[0038] The composition comprises an aqueous dispersion comprising one or more cupric compounds, one or more alkaline-earth metal hydroxides, one or more dispersing agents, and one or more defoaming agents.

[0039] The cupric compounds and alkaline-earth metal hydroxides constitute the active components of the composition, while the dispersing agents and defoaming agents promote the application thereof onto the plant.

[0040] In particular, the dispersing agents ensure a homogeneous aqueous dispersion, and the defoaming agents allow for the even distribution thereof onto the plant. In fact, the defoaming agents reduce bubble formation during the application of the composition and allow for a homogeneous coating of the parts to be treated. Preferably, the defoaming agent is selected from the list comprising: ethoxylated derivatives, polypropylene and polypropylene glycol derivatives, silicones, and polyester-based resins.

[0041] The cupric compound is selected from a cupric salt, a basic cupric salt, a Bordeaux mixture with the formula CuSO4’3Cu(OH)2-3CaSO4, cupric oxychloride, cupric oxide, cupric hydroxide, a combination of the same.

[0042] The term “cupric salt” relates to a water-soluble salt of Cu++, e.g. cupric nitrate, cupric chloride, or cupric sulfate.

[0043] In this description, the terms “bivalent”, “cupric”, and “copper” are interchangeable and always refer to bivalent copper.

[0044] Typical examples of basic cupric salts are CuSO4-3Cu(OH)2 and CUCO3-3CU(OH)2.

[0045] Bordeaux mixture is a well-known cupric-based contact fungicide with preventive action, used as a fungicide in agriculture, which is prepared by neutralizing pentahydrate cupric sulfate with calcium hydroxide.

[0046] Neutralization is necessary to counteract the phytotoxicity of pure cupric sulfate. Bordeaux mixture typically has a pH of between 6.0 and 8.5, preferably of between 6.5 and 7.5, while the cupric content ranges from 26% by weight to 27.5% by weight, preferably from 26.5% by weight to 27% by weight. Slight variations in cupric levels and pH are, of course, tolerated.

[0047] Cupric oxychloride, CuC12-3Cu(OH)2, has a pH of between 6.0 and 7.5,preferably of between 6.5 and 7.0, and the cupric content of oxychloride can range from 56% to 59%, preferably of between 57% and 58% Cu. Of course, slight variations in cupric levels and pH may be tolerated.

[0048] Cupric oxychloride can be obtained by alkaline precipitation from cupric chloride according to the reaction:

[0049] 4CUC12+ 6OH- CUC12-3CU(OH)2+ 6 Clin an even more preferred embodiment, the cupric compound is derived from Bordeaux mixture, cupric oxychloride, and mixtures thereof.

[0050] The alkaline-earth metal is selected from the group consisting of calcium, magnesium, or a combination of the same.

[0051] Preferably, the alkaline-earth metal is calcium.

[0052] Preferably, therefore, the alkaline-earth metal hydroxide is calcium hydroxide. The term “calcium hydroxide” relates to pure calcium hydroxide or calcium hydroxide containing the usual impurities, mainly MgO, CaO, and CaCCh. For the purposes of the present invention, technical-grade calcium hydroxide containing the aforementioned impurities may be used.

[0053] Usefully, the one or more alkaline-earth metal hydroxides and the one or more cupric compounds are present in a ratio by weight of 31 / 1 to 5 / 1.

[0054] The composition of the present invention is prepared by mixing the cupric compound and the alkaline-earth metal hydroxide together until homogenized, preferably in the presence of dispersing agents.

[0055] It is also preferable that the components be not only mixed but also ground until solid particles are obtained having a mean diameter preferably of between 0.4 pm and 40 pm.

[0056] The aforementioned particle size distribution can be obtained by using high-efficiency grinders.

[0057] In the preferred embodiment, the composition of the present invention is used in the form of an aqueous dispersion.

[0058] The term “aqueous dispersion” indicates that the active composition of the present invention is not soluble in water but exists in the form of solid particles evenly dispersed in water.

[0059] It is known that the presence of dispersants that are soluble in water is necessaryto obtain even aqueous dispersions.

[0060] They are necessary to promote wetting of the solids content, to obtain stable dispersions, and to ensure long-term stability (e.g., to prevent changes in viscosity, phase separation, and particle coalescence).

[0061] Usefully, the dispersing agent is selected from the group consisting of alkaline metal lignin sulfonates, alkaline-earth metal lignin sulfonates, and ammonium lignin sulfonates.

[0062] Other dispersing agents that can be used for the purposes of the present invention are: ethylene oxide and propylene oxide copolymers, salts of polynaphthalene sulfonates condensed with formaldehyde and lignin sulfonates. Even more commonly used are ammonium lignin sulfonates, which are permitted in organic farming under EEC Regulation No. 2092 / 91 of June 24, 1991.

[0063] The amount of dispersing agents will vary depending on various factors, such as the solids content, the particle size of the solids, the type of dispersing agent, etc.

[0064] As a general yet non-limiting guideline, the dispersing agents are present in a concentration by weight of between 1% and 10% with respect to the total weight of the composition.

[0065] Preferably, the dispersing agents are present in a concentration by weight of between 2% and 8% with respect to the total weight of the composition, and even more preferably in a concentration by weight of between 4% and 6% with respect to the total weight of the composition.

[0066] The aforementioned aqueous dispersion may also contain other compounds with different functions, e.g. surfactants, wetting agents and thickening agents, which are well known compounds to those skilled in the art.

[0067] In the compositions of the present invention, the alkalinity of the alkaline-earth metal hydroxide and the concentration thereof with respect to the other compounds is so high as to make all present basic cupric salts unstable, converting them into cupric hydroxide:

[0068] CUSO4’3CU(OH)2 + Ca(OH)i 4 Cu(OH)2 + CaSC (for brochantite, a component of the Bordeaux mixture)CUC12’3CU(OH)2 + Ca(OH)2 4 Cu(OH)2 + CaCh (for cupric oxychloride) In turn, due to Fe(II) impurities, which are always present in trace amounts, cuprous hydroxide is metastable, and Fe(II) catalyzes the conversion thereof to black oxide (see US 6,596,246), according to the following reaction:

[0069] CU(OH)2CuO + H2O

[0070] It would therefore appear that the active component of this formulation when placed in water is, ultimately, a mixture of CuO + Cu(OH)2 in unknown proportions that depend on the degradation of the hydroxide.

[0071] Usefully, the one or more alkaline-earth metal hydroxides and the one or more cupric compounds are altogether present in the aqueous dispersion in a concentration of between 1 kg / 100 liters and 5 kg / 100 liters, preferably of between 2 kg / 100 liters and 4 kg / 100 liters.

[0072] Typically, the aforementioned dispersion should be applied at a rate of approximately 1000 liters per hectare of field.

[0073] In a first embodiment of the present invention, the composition is made up of:

[0074] Cupric oxychloride: 5% to 10% by weight;

[0075] Zinc oxide: 0.5%-l%

[0076] Calcium lignin sulfonate: 1% to 5% by weight;

[0077] Ammonium lignin sulfonate: 1% to 5% by weight;

[0078] Defoaming agent: 0.5%-5%

[0079] Calcium hydroxide: 100% by weight.

[0080] In a second example of the present invention, the composition is made up of:

[0081] Bordeaux mixture (CuSO4-3Cu(OH)2-3CaSO4): 5-10% by weight, Calcium lignin sulfonate: 1% to 5% by weight,

[0082] Ammonium lignin sulfonate: 1% to 5% by weight,

[0083] Defoaming agent: 0.5%-5%

[0084] Calcium hydroxide: 100% by weight.

[0085] Both of the aforementioned compositions can be registered as EC fertilizers, permitted in organic farming.

[0086] Regarding the treatment of olive tree plants with the aqueous dispersion described above, it is preferable to carry out at least three treatments per year on the olive grove, starting in July with applications approximately once a month.Depending on weather conditions, additional treatments may be necessary. In fact, in the event of heavy rain, the formulation according to the invention is washed off the foliage and must therefore be reapplied.

[0087] The dispersion is sprayed onto the plants using standard sprayers.

[0088] According to the hypothetical mechanism of action of the active composition of the present invention, once sprayed onto the plant at the concentrations indicated above, calcium hydroxide, or alternatively magnesium hydroxide, operates as an airborne binding, converting into carbonate according to the reaction:

[0089] M(0H)2+ CO2MCO3+ H2O

[0090] where M = Ca, Mg.

[0091] In-situ carbonation creates a white, hard-to-wash-off coating on the surface of the leaves and fruit; this disorients the insect and discourages it from reaching the plant.

[0092] This physical effect is very persistent and visible for many weeks; therefore, the use of the product is economically advantageous.

[0093] The carbonation of the base present in the “active component” causes a rapid change in pH from a very high value to a value compatible with the plant’s physiology.

[0094] For this reason, the product does not harm the crop in any way.

[0095] Finally, the copper present in the active component of the formulation interacts with the symbiotic microorganisms of the olive fruit fly, hindering the activity thereof.

[0096] The insect therefore suffers from this lack of bacterial activity and tends to move elsewhere.

[0097] The synergistic action of the two effects, namely the physical coating effect and the chemical effect of copper allows for excellent results in controlling the olive fruit fly.

[0098] The frequency of treatment depends on two factors: the washing of the product off the plant’s surface and the increase in the number of insect flights, which can be monitored using sticky traps.

[0099] Another key aspect is the control of evapotranspiration.By coating the plant with a white compound, such as that obtainable using the active component of the present invention, greater reflection of sunlight is achieved, thus reducing the heat absorbed by the plant.

[0100] Thanks to this aspect, it is possible to reduce the crop’s water stress, thereby reducing the plant’s water requirements.

[0101] Compared to the prior art, the composition of the invention offers several advantages and achieves the intended objects.

[0102] First of all, all components are of natural origin or permitted in organic farming, and the composition’s risk (toxicity) class is very low; therefore, its use poses no particular risks to the operator.

[0103] Furthermore, its action against the insect is mainly of the mechanical / physical type, thus preventing easy recognition of the fruit by covering the treated parts and thus does not trigger the “resistance” processes typical of synthetic insecticides and resulting from their repeated use over the years.

[0104] Furthermore, given the low toxicological, ecological, and environmental profile of all the components of the formulation, it is unlikely to be subject to restrictions in the near future.

[0105] Furthermore, the positive side effect of protecting the treated plants against “heat stress” caused by the sun, due to the reflective power of the formulation once sprayed on the plants, allows for better water balance within the plant, resulting in reduced susceptibility to problems associated with periods of drought.

[0106] Finally, the formulation has a beneficial effect in limiting certain fungal pathogens {Spilocea oleagina, Pseudomonas syringae) and bacterial pathogens {Agrobacterium tumefaciens) due to the presence of copper.

Claims

CLAIMS1) Composition for the treatment of pests of the olive tree plant, characterized by the fact that it comprises an aqueous dispersion comprising one or more cupric compounds, one or more alkaline-earth metal hydroxides, one or more dispersing agents and one or more defoaming agents.2) Composition according to claim 1, characterized by the fact that said defoaming agent is selected from the list comprising: ethoxylated derivatives, polypropylene and polypropylene glycol derivatives, silicones, polyester-based resins.3) Composition according to one or more of the preceding claims, characterized by the fact that said cupric compound is selected from a cupric salt, a basic cupric salt, a Bordeaux mixture having formula CuSO4’3Cu(OH)2-3CaSO4, cupric oxychloride, cupric oxide, cupric hydroxide, a combination of the same.4) Composition according to one or more of the preceding claims, characterized by the fact that said alkaline-earth metal is selected from the group consisting of calcium, magnesium, a combination of the same.5) Composition according to one or more of the preceding claims, characterized by the fact that said alkaline-earth metal is calcium.6) Composition according to one or more of the preceding claims, characterized by the fact that said one or more alkaline-earth metal hydroxides and said one or more cupric compounds are present in a ratio by weight of 31 / 1 to 5 / 1.7) Composition according to one or more of the preceding claims, characterized by the fact that said one or more alkaline-earth metal hydroxides and said one or more cupric compounds are altogether present in said aqueous dispersion in a concentration of between 1 kg / 100 liters and 5 kg / 100 liters. 8) Composition according to one or more of the preceding claims, characterized by the fact that said dispersing agent is selected from the group consisting of alkaline metal lignin sulfonates, alkaline-earth metal lignin sulfonates, ammonium lignin sulfonates.9) Composition according to one or more of the preceding claims,characterized by the fact that said dispersing agent is present in a concentration by weight of between 1% and 10% with respect to the total weight of said composition.10) Composition according to one or more of the preceding claims, characterized by the fact of being made up of:Copper oxychloride: 5% to 10% by weight;Zinc oxide: 0.5% to 1%.Calcium lignin sulfonate: 1% to 5% by weight,Ammonium lignin sulfonate: 1% to 5% by weight,- Defoaming agent: 0.5% to 5%.Calcium hydroxide: 100% by weight.11) Composition according to one or more of the preceding claims, characterized by the fact of being made up of:Bordeaux mixture (CuSO4-3Cu(OH)2-3CaSO4): 5 to 10% by weight, - Calcium lignin sulfonate: 1% to 5% by weight,Ammonium lignin sulfonate: 1% to 5% by weight,Defoaming agent: 0.5% to 5%.Calcium hydroxide: 100% by weight.