RO115774B1 - Fungicidal composition with controlled release of the active substance and process for preparing the same - Google Patents

Abstract

The invention relates to a composition with controlled release of the active substance, comprising 10...12 parts cupric zeolite having the formula 0.78 CuO . 0.22 Na2O . Al2O3 . 5.16 . SiO2 . 8.9 H2O, 30...35 parts kaolin, 3.5...4.0 parts 5% calcium alginate and 1.75...2 parts water, said parts being parts by weight, and to a process for preparing the same.

Description

The invention relates to a composition with controlled release of the active substance and to a process for its preparation, a composition intended for treating the disease of vegetables.

Copper fungicides such as Bordeaux juice, copper sulfate, copper oxychloride, copper hydroxide are known. [guidance on the use of plant protection products - T. Baicu, 1980].

These products have the disadvantage that they are applied in high doses of the active substance, the copper ions favoring the pollution with pesticides, and they have a small area of application due to the latent phytotoxicity for some crops.

A controlled release copper fungicide of the active substance conditioned as a wettable powder is known and which is based on a zeolite structure obtained by hydrothermal synthesis FR 2619991, which removes the deficiencies of the copper fungicides mentioned above. This product has disadvantages with regard to the difficult formulation for the application of the treatment and the loss of substance, when applied.

The technical problem, which the invention solves, consists in finding a composition and conditioning it, so as to allow maximum use of the active substance by the slow, controlled release of the copper ions, increasing the performance of the fungicide application.

The composition according to the invention consists of 10 ... 12 cubic zeolite parts of the formula:

0.78 CuO. 0.22 Na ₂ 0. AI ₂ O ₃ . 5.16 Si0 ₂ .8.09 H ₂ 0

30 ... 35 parts kaolin, 3.5 ... 4.0 parts calcium alginate 5% and 1.75 ... 2 parts water, the parts being expressed by weight.

The invention also relates to a process for the preparation of the composition consisting of heating the primary zeolite in 3 steps, at a temperature of 1OO ° C, for 6 hours and a rest of 18 hours, treating the precipitated crystals with a solution of CuSO ₄ 1M for The copper zeolite was obtained and then stirred with 5% sodium alginate and kaolin solution and stirred in CaCl ₂ 10% solution.

The invention has the following advantages:

- a form of conditioning of the corresponding composition is made, for the loss-free application of the active substance,

- a relaxed, easy to obtain and processed zeolitic structure is obtained,

- The composition has a higher efficiency in combating bacterial diseases of vegetables (tomatoes and cucumbers).

The following is an example of an embodiment of the invention.

The synthesis of the primary zeolite is achieved by dissolving 15 ... 16 g of sodium aluminate and 64 g of caustic soda in 2750 ml of distilled water. This solution is added to

352.4 ... 375.9 g of sodium silicate, with stirring The substance thus obtained has the formula:

13.9 Na ₂ 0. AI ₂ 0 ₃ . 28.2 Si0 ₂ . 470.9 H ₂ 0

It is introduced, in the reactor, primary zeolite, stirred at ambient temperature for 24 hours and then heated in 3 equal steps, with stirring, at 100 ° C, for 6 hours, with breaks of 18 hours, during which the product returns to ambient temperature.

The crystals obtained are filtered and dried at 12 ° C for 16 hours, after which they are moistened and sieved.

After the exchange of copper ions with a solution of CuSO ₄ 1M, the copper zeolite has the following formula: 0.78 CuO. 0.22 Na ₂ 0. AI ₂ 0 ₃ . 5.16 Si0 ₂ . 8.09 H ₂ 0.

90 g of the substance are obtained.

RO 115774 Bl

The copper fungicide composition for application is formulated as granules for soil treatment, as follows: 75 ... 80 g sodium alginate solution

5% with 10 ... 12 g product and 30 ... 35 g kaolin are homogenized and co-preserved in CaCl ₂ 10% solution, with stirring. The obtained granules are dried up to 4% waste water. 50

In order to test the efficacy of the product in the control of bacterial diseases of vegetables (tomatoes and cucumbers), diseases in which the usual cupric fungicides have a limited efficacy, experiments were carried out under controlled conditions. The seeds of tomatoes and cucumbers, respectively, were sown in a soil mixture: grain: red peat: sand 3: 1: 1: 1. The zeolitic copper fungicide was applied to the sowing. The 55 tomato plants, respectively cucumbers, were allowed to grow. When the flowers of the plants appeared, they were infected with phytopathogenic bacteria Pseudomonas tomato and Pseudomonas lacimans, respectively, by sprinkling under pressure (0.5 bar) a suspension of 10 ⁶ bacteria / ml. There were made 4 experimental variants, 1 untreated infected control, 2 treatments with standard products (Cuzin 15 CA and Dithane M45) and the test version of 60 product made according to the example presented in this proposal of the invention. Each variant was made in three repetitions.

The results presented in Table 1 and Table 2 demonstrate a higher efficiency of the product made according to the example presented in this invention, provided that the amount of active substance applied (cubic ions) was reduced by about 10 times.

Table 7

The efficacy of the copper fungicide In combating the pustular stain of tomatoes [Pseudomonas tomato] and

Experimental variant Active substance concentration The frequency of the attack Untreated infected witness - 46.17 Cuzin 15 CA 0.15 16.23 Dithane M45 0.15 14.72 Cu-zeolite (cf. e.g.) 0,015 11.04 DL 5% 8.62

Table 2

Efficacy of the copper fungicide in combating the angular stain of cucumbers [Pseudomonas lacrimans]

Experimental variant Active substance concentration The frequency of the attack Untreated infected witness - 68.87 Cuzin 15CA 0.15 21.34 Dithane M45 0.15 34.15 Cu-zeolite (cf. e.g.) 0,015 18.42 DL 5% 12.07

Claims (2)

1. Fungicidal composition, with controlled release of the active substance, based on copper zeolite with the general formula of CuO. (1st) M ₂ 0. AlgOg.bSiOg. ΟΤ, Ο where M is Na and / or K and a, b, c are O <a <1; 3 <b <12; O <C <20, characterized in that it consists of 10 ... 12 cubic zeolite parts of the formula 0.78 CuO. 0.22 Na ₂ 0. AI ₂ 0 ₃ . 5.16 Si0 ₂ . 8.09 H ₂ 0 30 ... 35 parts kaolin, 3.5 ... 4.0 parts calcium alginate 5% and 1.75 ... 2 parts water, parts being expressed by weight. 2. The process for preparing the composition defined in claim 1, which comprises the step of obtaining the primary zeolite of formula 13.9 Na ₂ 0. AI ₂ 0 ₃ . 28.2 SiOg. 470.9 H ₂ 0 and the copper zeolite, respectively, by continuous heating at 100 ° C, for 24 hours, characterized in that the primary zealite is heated in steps, at 100 ° C, for 6 hours, and After 18 hours of rest, the precipitated crystals are treated with a solution of CuSO ₄ 1 M to obtain the copper zeolite and then stirred under stirring with the 5% sodium alginate solution and with kaolin and coated in CaCl ₂ 10% solution.