DD229584A1 - FUNGICIDAL AGENTS - Google Patents

Abstract

The agents according to the invention can be used in agriculture and horticulture for the control of fungal diseases on crop plants, in particular against Phytophthora infestans. As active ingredient they contain copper complexes of 1,2-benzoquinone dioxime.

Description

VEB CHEMIEKOMBIHAT BITTERFELD

Fungicidal agent

Field of application of the invention

The compositions according to the invention can be used in agriculture and horticulture for combating fungal diseases on crop plants, in particular against Phytophthora infestans.

Characteristic of the known technical solutions

It is known that in addition to organometallic compounds of ethylene-bis-dithiocarbamic acid, ζ · Β. Maneb (US Pat. No. 2504,404, US Pat. No. 2,710,822), Mancozeb (DE Pat. No. 996,264, US Pat. No. 250,4404) and Zineb (US Pat. No. 2,457,674) will also make use of inorganic metal compounds as fungicides to a large extent; Particular mention should be made of preparations containing copper, mercury and tin. The copper compounds are known to be of great practical importance for combating fungal diseases in potato, tomato, vine and banana production. Copper chloroside, the most important representative of the inorganic metal compounds, can hardly be surpassed in its action against downy mildew fungi, for example against the late blight on tomatoes or potatoes. However, the copper content of these preparations is unacceptable

? DEC 1934 * 2 I S0H2

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high; Another disadvantage is the often low plant tolerance.

Object of the invention

The aim of the invention is to develop new fungicidal agents, in particular against Phytophthora infestans, with reduced copper content.

Explanation of the essence of the invention

This object is achieved in that the fungicidal agent in addition to conventional auxiliaries and excipients as the active ingredient copper complexes of 1,2-Benzοchinondioxims the general formula

ΙΓ, ο-J) - H- O ^ -

$ -? Q- H - θ "-

in which R β is Η, halogen, alkyl or alkoxy.

It has been found that the copper complexes of 1,2-Benzochinondioxims have very good fighting properties against Phytophthora infestans. Compared to commercially available preparations, for example copper oxychloride, the agents according to the invention have a higher fungicidal activity against Phytophthora infestans with a significantly lower percentage of copper and are better tolerated by plants. The 1,2-benzoquinone dioximes used as ligands are, by known methods, £ ~ Zh. Obschch. Khim. 28, 2095 (1958); Heterocycles 1, 351 (1981) "J can be prepared from the appropriately substituted benzofuroxanes by reduction with hydroxylamine hydrochloride or thiourea.

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The copper (II) complexes of the invention are obtained by an alcoholic 1 ^ -Benzochinondioxim solution at 35. 50 ⁰ C is treated with an aqueous copper salt solution £ ~ Z. Haturforschung 30b, 535 (1975) _7 The. Complexes were identified by their IR spectra and elemental analyzes; Table I contains some active substances according to the invention whose fungicidal activity has been tested.

Table I: Selected active compounds according to the invention

connection R fp , 1 H . 36O ⁰ C 2 Cl 36O ⁰ C 3 -OCH ₃ 36O ⁰ C 4 -CH-. 36O ⁰ C 5 H2 ° C (1,2-benzoquinone dioxime) 6

(Copper oxychloride, reference substance)

The active compounds according to the invention can be converted into emulsifiable concentrates, pastes, granules and wettable powders. The forms of application of the active compounds according to the invention are prepared by mixing the active compounds with extenders, optionally with the use of surfactants * such as emulsifying and / or dispersing agents. Suitable solid extenders are minerals such as alumina, talc, kaolins, chalk or ground synthetic minerals such as finely divided silica and silicates. Emulsifiers are nonionic and anionic emulsifiers and dispersants are sulfite liquors and methyl cellulose.

The active compounds are used in the form of their formulations or of emulsions, suspensions, pastes or granules prepared therefrom, by spraying, spraying or dusting.

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embodiments

The active ingredient numbers listed in Tables II to IV correspond to the information in Table I.

example 1

In vivo test on tomato leaves

Intact leaves of tomato plants were treated with a spray mixture containing 0.1 and 0.01 % active ingredient of the compositions of the invention. After drying the spray coating was infected with the test fungus. The incubation was carried out at 20 ⁰ C and 96-100 % relative humidity in a humid chamber, The leaf infestation by the harmful fungus was determined 5 days after infection, while the plant compatibility was tested. The following bonus scheme was used:

rating scale;

Phytophthora effect plant tolerance

1 = heavy infestation by phyto-1 = leaf severely damaged

phthora infestans, like untreated control

2 = average infestation 2 = mean damage

3 = low infestation 3 "minor damage

4 * no infestation, leaf healthy '4' leaf without damage

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Table II: Effect of the agents according to the invention against Phytophthora infestans on tomato leaves

connection Phytophthora effect 0.01 % 0.1 % 2,3 (4) 1 4.0 (4) 2 2,3 (4) 1.7 (4) 3 3.0 (4) 2,3 (4) 4 3.7 (4) 5 1.0 (4) 2,7 (4) Kupferoxyehlorid 4.0 (4) (Spray Cupral 45)

The average score from 3 repetitions was given as the credit score. "The phytotoxicity is recorded in brackets for the respective Phytophthora credit score.

Example 2

Effect of the agents according to the invention against Phytophthora infestans on tomato plants (greenhouse) The experimental procedure and evaluation were carried out analogously to Example 1; the results are summarized in Table III.

Table III: Effect of the agents according to the invention on Phytophthora infestans ^. intact tomato plants

Connection credit notes (% AS)

0.2 0.1 0.05 0.02

1 4.0 3.7 3.3 2.0

2 3.7 3.7 3.0 2.7 Spray cupral 45 3.0 2.7 2.7 1.0 (copper oxychloride)

2663

The compounds 1 and 2 show full effectiveness against Phytophthora infestans already at 0.2% active substance, whereas this effect is achieved in spray cupral 45 (copper oxychloride) only at 0.5% active substance. In comparison to the in vivo test (Table II), the compound 2 acts only on the intact tomato plant, which suggests an increase in the metabolism of the plant.

Table IV: Fungicidal activity and copper content of the compositions according to the invention in comparison with spray cupral 45

connection

Cu content {%)

Fungicides (0.1 % AS) in vivo test intact plant

1 18.9 4.0 3.7 2 15.8 2.3 3.3 3 16.0 3.0 4 17.4 3.7 copper oxychloride 55 2.7 (Spray Cupral 45)

From Table IV it can be seen that the compositions according to the invention have a better or equal activity against Phytophthora infestans than the standard fungicide spray-Gupral 45 (copper oxychlorides whereby a considerable saving; -an valuable copper is achieved.

Claims (1)

2663 Invention Sans-Pruch Fungicidal agents, in particular against Phytophthora infestans, characterized in that they in addition to conventional auxiliaries and excipients as the active ingredient copper complexes of 1,2-Benzochinondioxims the general formula O - - -H-O- in which R = H, halogen, alkyl or alkoxy.