DD241844A1 - FUNGICIDAL AGENT, PREFERABLY FOR COMBATING PHYTOPHTORA INFESTANS - Google Patents

Abstract

The invention relates to novel fungicidal agents, which are preferably suitable for the control of Phytophthora infestans, but also Erysiphe graminis and Septoria apii. As active ingredient they contain 2-imino-3,4-disubst.-D4-thiazolines or their hydrochlorides. They are characterized by a particularly good effect and high plant compatibility.

Description

or cyclohexyl,

R ¹ = hydrogen or chlorine,

R ² = hydrogen, C 1 -C ₄ -alkyl, halogen, methoxy, nitro or 4-nitrophenoxy,

R ³ = hydrogen, chlorine, methyl or 2-nitro-phenoxy and R ⁴ = hydrogen, 2,4-dichloro-phenoxy, methoxy or nitro mean.

Field of application of the invention

The present invention relates to novel fungicidal compositions which are suitable for controlling Phytophthora infestans, and Erysiphe graminis and Septoria apii in agricultural crops.

Characteristic of the known technical solutions

For controlling harmful fungi on crops, in particular for controlling the pathogen of late blight on potatoes and tomatoes, organometallic compounds of ethylene-bis-dithio-carbamic acid, eg. B.

Maneb (US Pat. No. 2,504,404; 2,710,822), Mancozeb (US Pat. No. 2,504,404, BE Pat. No. 996,264) and Zineb (US Pat. No. 2,457,674). It is known that the disadvantages of the metal salts of ethylene-bis-dithio-carbamic acid are, above all, that they are not well tolerated by plants and their effect on Phytophthora infestans at low application rates unsatisfactory

Inorganic copper salts, e.g. As cupral, are known to be widely used against Phytophthora infestans. However, their effect is only prophylactic and also large amounts are needed.

Recently, acylated 2,6-disubstituted aniline derivatives, e.g. N- (1-carbmethoxyethyl) -N- (methoxyacetyl) -2,6-dimethylaniline (Ridomil) used against Phytophthora infestans. (DE-OS 2212268; BE-PS 1445387; US-PS 4141989) However, these compounds are too expensive in the synthesis and therefore expensive; at low application rates' does not satisfy the effect here.

Another disadvantage of some of these agents is that in the initial stage crops, phytotoxic effects are produced which result in the plants being left behind in their development.

Object of the invention

The aim of the invention is to find new fungicidal agents against Phytophthora infestans with good plant tolerance, which have a high efficiency at low rates. At the same time, toxicological disadvantages of known commercial products are to be overcome, and problems of resistance development must be overcome by introducing these new agents.

Explanation of the essence of the invention

This object is achieved in that thiazolines of the general formula

I-R

C = NH

or their hydrochlorides,

in the R =

R ¹ = hydrogen or chlorine,

or cyclohexyl,

R ² = hydrogen, C ₁ -C ₄ -alkyl, halogen, methoxy, nitro or 4-nitrophenoxy, R ³ = hydrogen, chlorine, methyl or 2-nitrophenoxy

and R ⁴ = hydrogen, 2,4-dichlorophenoxy, methoxy or nitro,

mean, especially against such hard-to-control harmful fungi, such. B. Phytophthora infestans, are selectively effective. * "'

The thiazolines according to the invention can be prepared by known processes (Beyer, H .; Ruhling, G .: Chem. Ber. 89 (1956) 107; US Pat. No. 2,626,949).

As starting materials for the preparation of the compounds of the invention serve a-thiocyanato-acetophenone or 4-chloro-athiocyanato-acetophenone and aromatic amine hydrochlorides or cyclohexylamine hydrochloride. If one compares the compounds of the invention with known commercial preparations, it is surprisingly found that the best-rated new compounds of the invention are more effective against severely foulable harmful fungi, especially Phytophthora infestans, with improved plant tolerance. The new agents can be applied with known fillers and / or surfactants.

embodiments

Examples of the active compounds according to the invention are listed in Tables 1 and 2.

Table 1

 Έ-R

C = HH · HCl

Verb.-Nr. R R ¹ 1 C ₆ H ₅ H 2 3-CI-C ₆ H ₄ H 3 4-CI-C ₆ H ₄ H 4 2-C2H5-C ₆ H ₄ H 5 2-CH ₃ OC ₆ H ₄ H 6 C ₆ H ₄ -4-0- (2,4-CI ₂ ) -C ₆ H ₃ H

The melting points of compounds 1-6 are above 25O ⁰ C. In the IR spectrum, these compounds show the typical absorption bands for hydrochlorides.

Table 2

- C-

-3ST-R

HC

C = M

Verb.-Nr. R R ¹ CC) 7 4-FC ₆ H ₄ H 138 to 140 8th 4-CI-C ₆ H ₄ H 114bis115 9 4-Br-C ₆ H ₄ H 108bis110 10 4-NO ₂ -C ₆ H ₄ H 119 11 4-CH ₃ -OC ₆ H ₄ H 118bis119 12 2-CHy-C ₆ H ₄ H 92 to 93 13 cyclohexyl 4-CI 138

example 1

In the in-vivo test on tomato leaves, a very good fungicidal action of the agents according to the invention over the test fungus Phytophthorainfestans could be determined. Intact leaves of tomato plants were treated with a spray mixture containing 0.1% active ingredient of said compounds (formulated into a water emulsifiable or suspendible form). After the spray coating had dried, the test fungus was infected.

• Incubation was carried out at 20 ^° C. and 96-100% relative humidity in a moist chamber. The leaf infestation by the fungus was determined 5 days after infection according to the following Boniturschema, while also the plant compatibility of the compound is rated

 "Schadpilzwirkung plant compatibility

1 = heavy infestation 1 = leaf badly damaged

like untreated control

2 = average infestation 2 = mean damage

3 = low infestation 3 = minor damage 4 = no infestation leaf healthy 4 = leaf without damage

The results from this test are shown in Table 3.

The credit score is the average of 3 repetitions. The phytotoxicity is recorded in brackets at the respective Phytophthora Bonitumote. Values are to be assessed in relation to fungicides used as standard on the basis of maneb, zineb and copper oxychloride.

The best rated representatives of the agents of the invention are more effective than the standard fungicides used.

Table 3 Verb.-Nr. Boniturnote at 0.1% active substance in the spray mixture 1 4.0 (4) 2 4.0 (4) 3 4.0 (4) 4 4.0 (4) 6 4.0 (4) 7 3.7 (4) 8th 4.0 (4) 9 3.7 (4) 10 3.7 (4) 11 4.0 (4) 12. 4.0 (4) 13 3.0 (4) maneb 4.0 (4) Zineb 4.0 (4) copper oxychloride 3.3 (4)

At an application rate of 0.01% active ingredient in the spray mixture has z. For example, the connection 12 the credit score 2.3 iPhutntnvi7ität4.1auf. Pränarate »on the basis of Manfib. Zineb or Kuoferoxvchlorid have at the same concentration of

Example 2

Some representatives of the compositions of the invention also show a side effect against Erysiphe graminis. Oat plants were treated with a spray mixture containing 0.1% by weight of the active compound of said compounds. After the spray coating dried on was infected with spores of the test fungus. The infestation of the oat plants by Erysiphe graminis was determined after days according to the Boniturschema mentioned in Example 1. At the same time the plant compatibility of the compound was registered. The effect of the agents according to the invention on Erysiphe graminis is characterized in Table 4. These results were compared with the active ingredient chinomethionate. The phytotoxicity is given in parenthesis to the respective credit score.

Table 4 Verb.-Nr. Boniturnoten at 0.1% active ingredient in the spray mixture 7 3.0 (4) 12 3.7 (4) 13 3.0 (4) chinomethionat 3.7 (4)

Example 3

Some representatives of the compositions according to the invention, in addition to their action against Phytophthorainfestans have a side effect on Septoria apii in celery.

Celery plants were sprayed with a spray mixture containing 0.01% active ingredient, dripping wet. After the spray coating has dried on it is infected with a spore suspension of Septoria apii. The incubation is carried out at 18-20 ⁰ C and 96-100% relative humidity. The leaf infestation by the pathogen is made 7 days after the infection as in Example 1.

The results of this test are shown in Table 5. The phytotoxicity is given in parentheses of each credit score.

Table 5 Verb.-Nr. Boniturnote at 0.01% active substance in the spray mixture 1 3.0 (4) 2 3.0 (4) 3 2.3 (4) 4 2.3 (4) 5 3.0 (4) 6 2.3 (4) thiram 2.3 (4)

Claims (1)

Invention claim: Fungicidal agents, preferably for controlling Phytophthora infestans, characterized in that they in addition to conventional excipients and carriers compounds of the general formula or their hydrochlorides, in the R «