DD275391A1 - FUNGICIDES AND BACTERICIDES - Google Patents

Abstract

The invention relates to new fungicidal and bactericidal agents. As active ingredients, the new agents contain substituted cyanimidodithiocarbonates in addition to conventional auxiliary and tracer substances. The active compounds are particularly suitable for combating seed and soil-borne pathogens in seed dressing, for storing crops and for combating phytopathogenic plant diseases on aboveground plant parts.

Description

Field of application of the invention

The invention relates to novel fungicidal and bactericidal agents which are suitable for controlling plant parasitic fungi and bacteria in agricultural and horticultural crops.

Characteristic of the known technical solutions

For the control of fungal diseases on crops, salts of ethylene-bis-dithiocarbamic acid, for example Maneb (US Pat. No. 2,504,404), Zineb (US Pat. No. 2,457,674) and Mancozeb (US Pat. No. 2,457,674) are known, in particular, to a large extent against Phytophthora imestans (potato blight). US Patent No. 2504404; British Patent No. 996264) as protective agents. The disadvantages of these fungicides are that they do not have a systemic effect, have a low duration of action and are also not well tolerated by plants. Their effect on Phytophthora infestans is not satisfactory, especially at low application rates. Moreover, because of the possibility of forming the canzerogenic cleavage product ethylene thiourea, they are not safe from a toxicological point of view.

Furthermore, it is known that aeylierte 2,6-disubstituted aniline derivatives, such as N- (1 -CarmethoxymethyD-N- (methoxyacetyl) -2,6-dimethyl-aniline (Metalaxyl) (DE-PS 2212268, GB-PS 1445387, U.S. Patent 4,141,989) are very effective against Phytophthora infestans.

These compounds are very expensive in their synthesis and thus expensive to use. In addition, they have a high risk of resistance, so that a sole application hardly comes into question.

Furthermore, Phytophthora infestans inorganic copper compounds (ζ B. Kupferoxychlorid) can be used. A major disadvantage here is the high application rates and poor plant compatibility. It is known to use organic mercury compounds, for example phenylmercuric acetate (DR-PS 515075), as the mordant. These compounds have a broad spectrum of activity, but have a high warm-blood toxicity and an unfavorable residue behavior in the soil and thus represent a high environmental impact. In addition to the use of organic mercury compounds, the use of 1, n-diguanidino-S-azaheptadecanacetat (guazatine) (GB -PS 1114155) known as mordant. However, this active ingredient can only be prepared by complicated synthesis of raw materials that are not readily available from the technical point of view.

Furthermore, it is known that benzothiazoles, such as 2- (thiocyanatomethylthio) benzothiazole (TCMTB) are used as mordants. The universal use of this drug is limited by its very high acute toxicity. For the storage of root crops, agents based on benzimidazol-2-carbamic acid methyl ester (carbendazim) alone and in combination with 2-bromo-2-nitropropane-1,3-diol (bronopol) are known to be used as a bactericidal active ingredient. Disadvantage here is that a transferred from the herb on the tubers infestation by Phytophtora infestans can not be controlled. In addition, benzimidazoles tend to genetically fixed resistance.

The antibiotics (eg chloramphenicol) also used to control plant bacterioses have considerable disadvantages because of the often rapid formation of resistance and because of the use of the same or similar active ingredients in human medicine.

Furthermore, fungicidal and bactericidal agents based on unsymmetrically substituted esters of cyanimidodithiocarbonic acid are known from the prior art (DD-PS 241204). However, these active ingredients are accessible only by complicated chemical syntheses and moreover generally have a lower bactericidal activity, for example against Erwinia carotovorum. Against seed and soil-borne pests, for example Plioma betae or Rhizoctonia spp. they are ineffective.

Object of the invention "The object of the invention is to develop new broadly effective microbicidal agents for use in crop protection.

Explanation of the essence of the invention

The invention has for its object to develop new fungicidal compositions based on asymmetrically substituted Cyanimidodithiocarbonate, which also have a good bactericidal effect. This object is achieved in that the new agent in addition to conventional excipients and carriers as Wirkstof e compounds of the general formula

XGTi ₂ S

c = ν - G δ ν,

RS

in the

R is a lower alkyl, alkenyl or aralkyl radical and X is halogen

means included.

The new active compounds can be prepared by alkylation of potassium monoester salts of Cyaniniiuüdithiokohlfinsäure with chlorobromoethane (DD-PS 256693) and optionally subsequent Umhalogenierung by literature methods. They are suitable for use in funky and bactericidal agents and can be used in crop protection both to protect against fungus and / or bacterial plant diseases in oberinJibu! be used as seed dressing against seed and Bodsnbürtige pathogens. It has furthermore been found that the compositions according to the invention can be used in a particularly advantageous manner for the storage protection of root crops, for example potatoes, whereby it is possible to combat both typical storage spoilage and infections which are already present in the field by foliar infestation, for example with Phytophthora infestans to be transferred to the tubers.

embodiments

The examples which follow are intended to explain the fungicidal and bactericidal activity of the agents according to the invention in more detail. Table 1 summarizes some of the cyanimidodithiocarbonates used as active ingredients. The active ingredient numbers given in the examples correspond to the details in Table

Table I: Cyanimidodiinic carhonates of the general formula

XCH ₂ S

N-G =

RS

active substance R X Melting point ( ⁰ C) 1 CH ₃ Cl 58-60 2 C ₂ H ₆ Cl Oil 3 (CH ₂ I ₂ CH ₃ Cl Oil 4 CH ₂ (CH ₃ J ₂ Cl ül 5 CH ₂ CH = CH ₂ Cl Oil 6 CH ₃ J 73-75 7 CH2C6H5 Cl 47-50

example 1

Effect of the agents according to the invention in the in vitro test The test fungi Botrytis cinerea, Alternaria tenuis and Fusarium culmorum were inoculated on agar plate containing active compound concentrations of 0.1%, 0.01 and 0.001% of the agents according to the invention.

The evaluation of fungal growth was made after 10 days on the basis of the following credit score:

1 = no growth inhibition

2 = weak growth inhibition

3 = strong growth inhibition

4 = completely inhibited growth

The fungicidal action of the compositions according to the invention on o. G. Mushrooms are shown in Table II.

Table II: Inhibition of fungal growth by the agents according to the invention in the in vitro test

active substance

Conc. (%)

Alternaria tenuis

Botrytis cinerea

Fusarium culmorum

(Invention) 0.1 1 0.01 0.001 0.1 2 0.01 0.001 0.1 3 0.01 0.001 0.1 4 0.01 0.001 0.1 5 0.01 0,101 0.1 6 0.01 0.001 0.1 7 0.01 0.001 (known) 0.1 maneb 0.01 0.001 0.1 Zineb 0.01 0.001 0.1 carbendazim 0.01 0.001

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4

4 4 4 4 4 1 3 1 1

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 1 4

4 λ

4 4 4 4 1 1 4 4 4

Example 2

Effect of the Agents According to the Invention Against Yeasts and Bacteria in the Flütsig Culture Test The compositions according to the invention were added in dissolved state to liquid cultures of Torulopsis H24 or Erwinia carotovorum, concentrations in the medium being set at 100 to 1 ppm.

The percentage inhibition of proliferation was determined by photometric measurements. In Tables III and IV are the

Results from this test shown.

TABLE III Percent inhibition of proliferation of the agents according to the invention against Torulopsis H24

active substance Conc. (Ppm) Torulopsis H 24 (Erfinduncsgemäß) 1 100 100 10 - 1 - 2 100 100 10 100 1 100 3 100 100 10 100 1 100 4 100 100 10 100 1 100 5 100 100 10 100 1 100

Conc. (Ppm) Torulopsis H 24 Conc. (Ppm) Erwinia carotovorum -4- 275 391 Continuation of Table III 100 100 active substance 10 100 100 100 6 1 100 10 90 100 100 100 100 10 100 10 90 7 1 100 100 100 10 50 100 100 100 100 (known) 10 1 13 10 90 Zineb Table IV: Proprietary anti-proliferation of the inventive compositions against 100 100 Erwinia carotovorum 10 58 Wirkotoff 00 100 (Invention) IU 100 1 100 100 2 10 100 100 100 3 10 60 4 CJL 7 (known) bronopol chloramphenicol

Example 3

Effect of the agents according to the invention against Fusarium spec. On potato slices The agents according to the invention were sprayed onto potato tissue. Subsequently, the infection was carried out with fusarium spp., The causative agent of potato dry rot.

The evaluation took place after 5 days using the following rating scheme:

1 = no growth inhibition

2 = mean growth inhibition

3 = no infestation - tissue healthy

Table V: Effect of the agents according to the invention against Fusarium spp. on potato tissue active substance Conc. (Vo) Fusarium spp.

3 3 3 3 3 2

2 1 3 3

(Invention) 0.5 2 0.1 0.5 3 0.1 0.5 4 0.1 (known) 0.5 thiram 0.1 0.5 carbendazim 0.1

Example 4

Effect of the agents according to the invention on potatoes under loose storage conditions Freshly cleaned potatoes were treated with the compositions according to the invention in the wet pickling method. The potatoes were stored in mesh bags of 15kg each in the potato pile. The outsourcing took place after 6 months. At the time of the outsourcing, the proportion of tubers with rot was determined. The results are summarized in Table VI.

Table VI: Effect of the agents according to the invention In the potato storage

active substance Conc. weight loss Fäi.leverlust (guest) (%) (%) untreated control _ 13.3 2.95 (Invention) 4 120 8.7 0.12 (known) chloramphenicol 2.56 10.0 2.5 + Carbondazim 115.2

Example 5

Effect of the agents according to the invention against Phytophthora infestans

Tomato plants were treated with a spray mixture containing 0.1% and 0.01% active ingredient of the compounds of the invention, respectively, which in turn were formulated into a water emulsifiable or suspendible form.

After the spray coating had dried, the infection was carried out with zoospores of Phytophthora infestans. The incubation of the thus treated test plants was carried out at 20 ⁰ C and a relative humidity of 90-100%. 5 days after the infection, the movement of the infestation was made according to the following Boniturschema

1 = severe infestation by P. i. 30%

2 = average infestation by P. i. 11-30%

3 = low infestation by P. i. 1-10%

4 = no bofall 0%

The determination of the phytotoxicity takes place according to the following scheme:

1 = Plant severely damaged

2 - mean damage

3 = low damage

4 = sheet without damage

The results are shown in Table VII. The Boniturnote the phytotoxicity is in brackets behind the note for the effect.

Table VII: Effect of the agents according to the invention on Phytophthora infestans

active substance 1000 ppm 100 ppm (Invention) 2 4.0 (3.0) 4.0 (Λ, 0) 3 4.0 (4.0) 2.7 (4.0) 4 3.7 (3.0) 2.7 (4.0) 7 3.0 (4.0) 3.0 (4.0) (known) Zineb 4.0 (4.0) 1.7 (4.0) metalaxyl 4.0 (4.0) 4.0 (4.0) carbendazim 4.0 (4.0) 1.0 (4.0)

Example β

Effect of the agents according to the invention as mordant against seed- and soil-borne pathogens Monocarpes sugar beet seed was treated with the agents according to the invention at application rates of 0.2%, 0.1% and preferably 0.05% by dip pickling.

Afterwards, the seeds were laid in soil infected with soil-borne pathogens. In the case of testing against seed-borne pathogens, seed already infected during the harvesting process was pickled with the compositions according to the invention and then also laid out in steamed soil.

The results from this test are shown in Tables VIII to X below.

Table VIII: Effect of the agents according to the invention against seed-borne pathogens using the example of Phoma betae

active substance Conc. (%) healthy plants (%) (Invention) 5 0.05 81.6 7 0.05 83.3 untreated - 63.3 (known) phenylmercuric 18 g / 100 kg 83.3

Table IX: Effect of the agents according to the invention against soil-borne pests using the example of Phythium spp.

Active substance conc. (%) Healthy plants (%)

(Invention) 0.1 56.6 2 0.1 60.0 3 - 26.6 untreated (I know) 18g / 100kg 58.3 phenylmercuric

Table X: Effect of the agents according to the invention on soil-borne pathogens using the example of Rhizocotonia spp.

Active substance conc. (%) Healthy plants (%)

(Invention) 0.2 56.6 3 0.2 60.0 4 0.2 58.3 5 - 33.3 untreated (known) 18g / 100kg 60.0 phenylmercuric

Claims (1)

Fungicides and bactericidal agents for controlling seed-borne and soil-borne pathogens in seed dressing, in the storage of crops and for controlling phytopathogenic plant diseases on aboveground plant parts, characterized in that they cyanimidodithiocarbonates the general formula in addition to conventional excipients and carriers as active ingredients XCH ₉ S ^ά G = N-CSN, RS in the R is a lower alkyl, alkenyl or aralkyl radical and X is halogen
means included.