CS197240B2 - Fungicide means with the systemic wffwect - Google Patents

Description

The invention relates to a fungicidal composition having a systemic action.

British Patent Specification No. 1,109 * 937 discloses fungicides consisting of a mixture of Zineb or Maneb containing a basic copper salt. The preparation and properties of Zineb and Maneb are described in detail in U.S. Patent Nos. 2,504,404 and 3,085,042.

As is known, copper hydroxide, copper oxychloride and copper oxysulfate are the most commonly used chemicals for combating vine perenospore. When used, they are practically insoluble and are therefore very stable, but have the disadvantage of slow and gradual dissolution at various atmospheric effects, thereby causing phytotoxic effects. These cytotoxic side effects lead to the formation of necrosis and yellowing or reddening of the leaves.

It is also known that certain dithiocarbamates can be used as fungiidal agents. For example, zinc ethylene bis-dithiocarbamate (Zineb) is extensively used to combat fungal diseases in cultivated plants, for example to combat vine perenospora. This substance has a favorable effect on plant growth, but its stability is inadequate because it decomposes relatively quickly.

Some commercially available plant protection products contain a combination of the above two chemicals as an effective basis. Because these chemicals enhance the effects of each other, most of these commercially available preservatives contain 50 to 8% by weight of the copper compound and 20 to 50% by weight of the dithiocarbamate derivative. However, these combinations can also cause deleterious phytotoxic side effects.

Since the rate of decomposition of dithiocarbamates increases substantially in the presence of copper compounds, known fungiid mixtures generally contain 1 to 10% by weight of metal ferrocyanide to suppress the decomposition of dithiocarbamate compounds. In this way, the rate of decomposition is greatly reduced and prolonged fungiid action can be ensured.

A further disadvantage of fungicidal compositions containing practically water-insoluble copper compounds is that they are to contain relatively high proportions of copper compounds, i.e., relatively much metallic copper. In order to ensure the desired fungieid effect, these combinations must occasionally contain 20 to 40% by weight of metallic copper.

The lack of magnesium that occurs in grapevines due to the intensive use of potassium fertilizers as a result of ionic antagonism releases plant tissue and makes the plant extremely susceptible to fungal diseases, thereby reducing the effectiveness of fungicidal compositions. According to current practice, this effect can be avoided by spraying the plants, in a separate step, with an aqueous solution of magnesium sulfate. However, this procedure increases the cost of plant protection considerably.

These drawbacks are largely eliminated with the fungicidal composition of the invention.

The principle of the systemic fungicidal composition according to the invention is that it contains, as active ingredient, 0.1 to 99.8% by weight of a mixture of magnesium ethylene bis-dithiocarbamate, an alkali metal salt and / or an alkaline earth metal glycyl-N, N-bis Copper-2-hydroxy-5-sulfobenzyl chelate and non-phytotoxic ferrous or ferrous iron complex, in the presence of 0.1 to 99.9% inert diluent and optionally 0.1 to 1% surfactant, the weight ratio of copper chelate to dithiocarbamate; and to the ferric or ferrous complex is 5 to 94.5: 5 to 94.5: 0.5 to 5.

The main advantage of copper chelates is that, unlike the copper compounds used hitherto, they are well soluble in water, but do not release copper ions into the aqueous solution and thus no phytotoxic side effects can occur. Due to the good water solubility of copper chelates, the desired fungicidal activity can be obtained for compositions containing much less metallic copper than conventional compositions.

Copper chelates are, in addition to their good water solubility, stable compounds and thus provide a prolonged fungicidal effect.

Furthermore, it is an important advantage of the copper chelates that their magnesium salts also exist, i.e. compounds containing substantial amounts of magnesium in addition to copper that can be released. Due to the amino acid content and water solubility, magnesium-containing copper chelates penetrate into leaf tissues and there magnesium ions produce a tissue-firming effect, thereby increasing the natural resistance of plants to fungi and thus enhancing the effect of fungicidal compositions.

In outdoor tests carried out with the mixtures according to the invention, it was found that the chlorophyll content of the leaves increased substantially and, unlike the tests carried out with known mixtures containing the usual water-insoluble copper compounds, no phytotoxic effect appeared.

In parallel tests with mixtures containing either copper oxychloride or copper chelates, it was found that plants treated with copper chelate had a darker green color than plants treated with a similar dose of copper oxichloride and did not appear a "copper shock" commonly known and undesirable phenomenon when insoluble copper compounds are used.

For water-soluble chelates, the desired fungicidal effect is ensured entirely at concentrations corresponding to a metallic copper content of 2.5 to 8% by weight.

In the compositions of the invention, the relative proportions of the three kinds of active ingredient (i.e., the dithiocarbamate component, the copper chelate component and the ferric or ferrous iron complex used as stabilizing agent) can vary within wide boundaries.

The total active ingredient content of the composition according to the invention may vary between 0.1 and 99.8% by weight. Particularly preferred compositions comprise 5 to 94.5% _{of the} copper copper chelate, 5 to 94.5% of the dithiocarbamate component and 0.5-5% of the stabilizing complex. In addition to the active ingredients, the composition may contain conventional additives such as surfactants, fillers, diluents, adhesives and the like.

The invention is explained in detail by the following non-limiting examples. Parts and percentages are by weight unless otherwise indicated.

Example 1

and)

A mixture containing 48 parts of 80% Zineb, 50 parts of copper glycyl-N-dimethylamino-bis-2-hydroxy-5-sulfobenzyl chelate and 1 part of ferric cyanate is finely ground and 1 part of solid fatty alcohol sulfate is mixed with the above mixture, to obtain better adhesion properties.

(b)

A mixture of 70 parts of 80% zinc magnesium ethylene bis-dithiocarbamate, 27 parts of magnesium glycyl-N-dimethylamino-bis-2-hydroxy-5-sulfobenzyl chelate magnesium salt, 2 parts of ferric ferrocyanide and 1 part of solid fatty alcohol sulfate ( adhesion promoter) is homogenized by fine grinding.

The mixtures thus obtained can be dissolved in water to the desired concentration and the aqueous mixtures can be sprayed directly onto the plants.

Example 2

Comparative outdoor tests were performed with the compositions of the invention and with known compositions as follows:

and)

A 0.4% aqueous suspension was prepared from a known fungicidal mixture containing 15% Zineb and an amount of copper oxychloride corresponding to 37.5% copper metal. This suspension was sprayed on the plants at 800 liters / ha and this treatment was repeated six times during the growing season.

(b)

A 0.40% aqueous suspension was prepared from a novel fungicidal mixture containing 48% Zineb, 2% ferric ferrocyanide and magnesium glycyl-N-dimethylamino-bis-2-hydroxy-5-sulfobenzyl chelate copper in an amount of 1977240

With equivalent to 5% metallic copper. This suspension was sprayed on the plants at 800 liters / ha and this treatment was repeated six times during the growing season.

During the observation period, it was found that plants treated with a novel composition containing copper chelate [i.e., mixture bj] had a better growth appearance than plants treated with a known composition containing an inorganic copper compound.

Copper shock could not be detected on plants treated with bj. The leaves were uniformly green in color, with no tissue release characteristic of plants treated with metal dithiocarbamate compounds.

Plants treated with b) were given a sufficient dose of magnesium, so that no yellowing of the leaves, characterized by a magnesium deficiency symptom and observable on the treated plants, etc., could be detected. Furthermore, bundle tendril paralysis, another characteristic symptom of magnesium deficiency, also occurred less frequently in plants treated with mixtures bj than in plants treated with mixtures, etc.

On vines treated with bj the leaves remained green in autumn, before vintage, for a longer period of time than on the treated bushes a) and necrosis appeared much less frequently. As a result of prolonged photosynthesis, the sugar content of the ripe grapes obtained after treatment with mixture b) was higher than that obtainable after treatment with mixture a).

The results of the above tests are summarized in Table 1.

TABLE 1

Mixture used for spraying Parallel tendrils Sugar must content

20. 7. 1972 27. 8. 1972 mg / l mixture etc. 0.8% 18% 16 mixture bj 0,9 '% 4% 19 Dec water 0.75% 19% 14

Example 3

In the outdoor test, vine bushes (variety: 'Kadarka') were treated against the fungus by spraying on the plants at 800 l / ha with a 0.4% aqueous suspension of the respective fungicidal mixtures.

aj

In a comparative experiment, the mixture contained 15% Zineb as active ingredient and copper oxychloride corresponding to 37.5% metallic copper.

bj

In the test experiment the mixture contained as the active substance 48% zineb, 2 o / ₀ ferric ferrocyanide and the magnesium salt of glycyl-N-dimethylamino-bis-2-hydroxy-5-sulfobenzyl copper chelate in an amount corresponding to 5% copper metal.

Tests have shown that the infectivity ratio of plants treated with mixture bj, despite the low copper content, was lower than that of plants treated with mixture a). This can be partly attributed to the presence of magnesium, which increases the efficacy of the fungicidal composition by strengthening leaf tissues and partly the use of a water-soluble copper compound.

The results of these experiments are summarized in Table 2.

TABLE 2

Mixture used Infectious degree treated parcel,% for spraying 10. 7. 20. 7. 27. 7. 7. 8. 16. 8. 27. 8. mixture a) 2,0 3.8 4.0 3.2 6.0 2.5 mixture b] 1,8 4.0 3.5 3.0 5.0 1.0 water 2.5 10.0 18.0 20.0 65.0 70.0

The systemic nature of the composition of the invention was determined by taking leaf samples from the treated plants at different times and determining their magnesium, copper and glycine content. Despite the low copper content of the mixture, it was found that the leaves taken from the plants treated with the copper chelate mixture contained barely less copper than the leaves taken from the plants treated with the insoluble copper compound mixture in larger amounts. This appearance clearly shows that copper chelate is absorbed by the leaves of the plant.

Similarly, the difference in magnesium content indicates that magnesium bound to the organic molecule is also absorbed by the leaves. The observed difference in glycine content leads to a similar conclusion.

The results of these tests are summarized in Table 3. The indicated figures (ppm for metals, mg / g for glycine) refer to dry leaf material.

TABLE 3

Mixture used for spraying Metal and glycine content in leaf samples 10. 7. 7. 8. 27. 8. Mg Cu Mg Cu Mg Cu Gly mixture etc. 3650 12 7200 40 1300 92 32 mixture b) 3540 15 Dec 3500 43 6500 100 ALIGN! 14 water 3700 14 3800 22nd 7000 19 Dec 12

Example 4 by spraying, is prepared by homogenizing 0.5 parts of a mixture of the compositions given under a) and / or b) z

Powder blend suitable for Powder Example 1 and 99.5 parts talc.

Claims (1)

Systemic action fungicidal composition comprising, as active ingredient, 0.1 to 99.8% by weight of a mixture of magnesium ethylene bis-dithiocarbamate, an alkali metal salt and / or an alkaline earth metal glycyl-N, N-bis-2-hydroxy -5-sulfobenzyl chelate of copper and non-phytotoxic ferric or ferrous ferric OF THE INVENTION in the presence of 0.1 to 99.9% by weight of inert diluent and optionally 0.1 to 1% by weight of surfactant, wherein the weight ratio of copper chelate to dithiocarbamate and to ferrous or ferrous iron complex is 94.5: 5 to 94.5: 0.5 to 5.