CH520474A - Fungicidal organophosphorus compounds - for agricultural use - Google Patents

Abstract

Fungicidal agents contain a compound of the formula RP(O)(SR')2 (I) (where R is ClCH2CH2- and R' is p-chlorobenzyl or R is methyl and R' is o-methylbenzyl), which have very good activity against Phycomycetes (e.g. phytopathogenic fungi such as Botrytis and Piricularia) and various other fungi causing diseases of cereals, maize, rice, vegetables, fruit and other cultures; (I) also display fungitoxic activity against soilborne fungi.

Description

  

  
 



  Fungicides
The present invention relates to fungicidal agents which contain the compound of the formula as active component
EMI1.1
 or the compound of the formula
EMI1.2
 contain, if necessary together with one or more of the following additives:
Solvents, dispersants, tackifiers, thickeners and / or fertilizers.



   The active ingredients of the formula (I) are very effective against representatives of the Phycomycetes class, e.g. B. phytopathogenic fungi such as botrytis and piricularia, but also against various other fungal pathogens on cereals, maize, rice, vegetables, fruit growing and other crops.



   They have a special effect on the following types of fungi: Cochliobolus miyabeanus species, Corticium species, Cerospora species, Alternaria species, Venturia inaequalis, Podosphaera Leucotricha, Uromyces phaseoli, Cercospora apii, Cercospora beticola, Cercospora musae, Piracysearum sp. Penicillium digitatum, Sphaerotheca humuli, Diplocarpon rosae, Uncinula necator, Coccomyces hiemalis, Cladosporium carpophilum, Erysiphe graminis hordei, Monolinia (Sclerotinia) Laxa, Monolinia (Sclerotinia) fructicola, Piricularia corinia, P. gructum corinia, P. glumaronzae, Puccuminia reconditae, Puccuminia recond tritici, Aspergillus niger, Aspergillus terreus, Rhizoctonia, Fusarium, Verticillium.



  This list does not claim to be complete.



   The active ingredients according to the invention or their compositions also show a fungitoxic effect on plants which attack the plant from the ground and sometimes cause tracheomycoses, such as Fusarium cubense, Fusarium dianthi, Verticillium alboatrum and Phialophora cinerecens.



   They can be obtained by the known methods for the preparation of phosphoric acid esters, e.g. B.



  by reaction of one mole of an alkane (thio) phosphonic acid dihalide
EMI1.3
 with 2 moles of an optionally ring-substituted benzyl mercaptan in the presence of an acid-binding agent such as triethylamine, alkali metal carbonate, alkali metal hydroxide solution or alkali metal alcoholate. If phosphonic acid esters with differently substituted benzyl radicals are to be obtained, the alkane (thio) phosphonic acid dihalide is reacted in succession with one mole each of the respective benzyl mercaptan. The exothermic reaction is preferably carried out with slight cooling.



   The agents which contain the active ingredients of the formula I or of the formula II can be applied in a wide variety of ways, e.g. B. in the form of aqueous sprays, dust powders, etc.



   Aqueous sprays can be produced, for example, on the basis of an emulsifiable concentrate or a wettable powder. A suitable emulsifiable concentrate can, for example, from about 25 parts of a compound of the formula (I), 40-50 parts of diacetone alcohol or isophorone, 20-30 parts of an aromatic petroleum product, xylene, toluene or another mixture of such solvents and 2-10 parts of one or several emulsifiers can be produced. Small amounts of an agent which promotes the formation of a homogeneous solution such as methanol, methoxymethanol or butoxymethanol can also be used.



   A suitable emulsifying agent can e.g. from 1-1.5 parts of calcium or sodium dodecylbenzenesulfonate, 2.54 parts of an octyl- or nonyl-phenoxypolyethoxyethanol and about 0.5-1 part of methanol and 0-0.8 parts of xylene.



   The resulting mixture is added to the solvents and the active body of the formula I or of the formula II in the proportions given above. However, one or more other surfactants can also be used.



   Any such agent, such as an anionic or cationic or a nonionic solvent soluble emulsifier, can be used as desired and convenient. Instead of the above-mentioned nonionic agent derived from an alkylphenol and ethylene oxide, for example ethylene oxide condensates of long-chain alcohols, carboxylic acids, phenols or amines can be used. Compounds of these types are commercially available. Nonionic condensates of polyglycerols and a resin-forming acid such as phthalic acid can also be used in the manufacture of self-emulsifying preparations. Typical anionic agents are those based on alcohol sulfonates, sulfates or sulfosuccinates. Cationic surfactants soluble in solvents are e.g. B.

  Oleylbenzyldimethylammonium chloride or dodecylbenzyltrimethylammonium chloride or bromide. It can be seen from this that the individual character of the emulsifier is of no particular importance, provided that it is soluble in the solution of the active ingredient in one or more inert organic solvents.



   A wettable powder can be obtained if the active ingredient of the formula I or the formula II is taken up in a volatile solvent such as acetone and brought together with a finely divided solid such as kaolin, pyrophyllite or diatomaceous earth with evaporation of the solvent. The powder is heated with small amounts of one or more wetting dispersants. A typical composition consists e.g. from 20 parts of an active ingredient of the formula I, 77.5 parts of one or more finely divided solids, 0.5 part of wetting agent, such as an octylphenoxy-polyethoxyethanol, and 2 parts of the sodium salt of methylene-bis-naphthalenedisulfonic acid.



   Dusts containing 5-10% of the active agent can be prepared by diluting such a wettable powder with a finely divided solid carrier. The wetting agent can be omitted if desired. If desired, the dispersant can also be omitted or replaced by others.



   Each of the fungicidal preparations described above usually contains a carrier and, in most cases, a surfactant.



   The agents according to the invention can be applied alone or in mixtures with other fungicidally active substances.



   Examples include: dodecylguanidine acetate (dodine) pentachlomitrobenzene (quintozene) pentachlorophenol (PCP) 2- (1-methyl-n-propyl) -4,6-dinitrophenyl-2-methylcronate (binapacryl) 2- (1-methyl) -n-heptyl) -4,6-dinitrophenyl crotonate (dinocap) 2,6-dichloro-4-nitroaniline (dichlorane) 2,3,5,6-tetrachlorobenzoquinone (1,4) (chloranil) 2,3-dichloro -naphthoquinone (1,4) (dichlone) N- (trichloromethylthio) phthalimide (Folpat) N- (trichloromethylthio) cyclohex-4-ene <1,2-dicarboximide (captan) N- (1,1,2,2-tetrachloroethylthio ) cyclohex-4-ene-1,2-dicarboximide (Captafol) N-methylsulfonal-N-trichloromethylthio-chloroaniline N'-dichlorofluoromethylthio-N-dimethyl-N'-phenylsulfamide <RTI

    ID = 2.13> (Dichlorfulamid) O-ethyl-S-benzyl-phenyldithiophosphate O, O-diethyl-S-benzyl-thiol phosphate disodium-ethylene-1,2-bis-dithiocarbamate (Nabam) zinc-ethylene-1,2-bis -dithiocarbamate (Zineb) Manganese (II) -ethylene- 1,2-bis-dithiocarbamate (Maneb) tetramethylthiuram disulfide (Thiram)
1 -Oxy-3 -acetyl-6-methyl-cyclohexen- (5) dione- (2,4) (Dehydroacetic acid) 8-hydroxyquinoline (8-quinolinol) 2-dimethylamino -6-methyl-5 -n-butyl- 4-hydroxypyrimidine methyl-N-benzimidazol-2-yl-N- (butylcarbamoyl) carbamate (benomyl) 2-ethylamino-6-methyl-5n-butyl-4-hydroxypyrimidine 2,3-dicyano -1, 4- dithia-anthraquinone (dithianon) 2- (4-thiazolyl) -benzimidazole 3,5-dimethyltetrahydro-1,3,5-thiadiazine-2-thione (Dazomet)

     2,3-Dihydro-5-carboxanilido-6-methyl-1 1, 4-oxathine pentachlorobenzyl alcohol
example 1
36.3 parts
EMI2.1
 and 63.4 parts of p-chlorobenzyl mercaptan are placed in 500 parts by volume of dry benzene. 42 parts of triethylamine are added dropwise at 5-150 ° C. and the mixture is then stirred overnight at room temperature. The hydrochloride is then washed out twice with 100 parts of water each time and the organic phase is shaken out successively with 50 parts by volume each in sodium hydroxide solution and water. After evaporation of the solvent, the compound of the formula is obtained as the residue
EMI2.2
 with a refraction value of nD23 1.6282.



   In an analogous manner, the compound of the formula
EMI2.3
    nD24 1.6099 produced.



   Example 2
40 parts by weight of an active compound are in a 25% strength xylene solution of a mixture composed of equal parts by weight of a condensation product of about 1 mol of p-tert. Octylphenol with about 10 moles of ethylene oxide and p-dodecyl-benzenesulfonic acid calcium consists, added and the whole thing made up to 100 parts by volume with xylene. When diluting with water to the desired concentration, a stable, very sprayable emulsion is created.



   Example 3 Fungicidal Action a) Action against Botrytis cinerea on Vicia faba
In Petri dishes, which have been lined with moistened filter paper, three fully developed, equal-sized leaves of Vicia faba were placed, which were prepared with an active substance (0.05% active substance content) prepared from the active substance formulated as 1 0% wettable powder Sprayer were sprayed dripping wet. When the leaves were dry again, they were infected with a freshly prepared, standardized spore suspension of the fungus (concentration: 100,000 spores / ml) and kept in a humid atmosphere at 200 ° C. for 48 hours. After this time, they showed black, initially point-like spots that spread rapidly. The number and size of the infection sites were used as a yardstick for assessing the effectiveness of the test substance.



  b) Action against Erysiphe cichoracearum on Cucumis sativus
Young Cucumis sativus plants were sprayed with a 0.05% suspension of the active ingredient formulated as a wettable powder and after the spray coating had dried off with a spore suspension of the fungus. After 8 days in the greenhouse at about 230 ° C., the degree of infestation (proportion of the leaf surface covered by the mycelium coating) on the infected, treated leaves was determined in comparison with untreated, infected controls.



  c) Action against Uromyces appendiculates on Phaseolus vulgaris
Phaseolus vulgaris plants in the two-leaf stage were sprayed to runoff point with a suspension of the substance formulated as a wettable powder (conc.



  0.05% active substance). After the spray coating had dried off, the plants were infected with a fresh spore suspension of the bean grate and then kept in a humid chamber for one day and then in a greenhouse at 20-220 ° C. for 12 days.

 

   The number and size of the rust pustules served as an evaluation standard for the effectiveness of the test substances.



  d) Action against Phytophthora infestans on Solanum Lycopersicum
S. Lycopersicum plants of the same variety and in the same stage of development were kept in a dry state after being sprayed with a broth of 0.05% active ingredient (made from the active ingredient worked up into a wettable powder) and sprayed dripping wet with a zoospore suspension of Ph. Infestans . They then remained in the greenhouse for 6 days at 18-200C and high humidity (95-100%) and after this time they showed typical leaf spots. The substance tested was assessed on the basis of their number and size.



   The compounds according to Example 1 showed fungicidal activity in the above tests a) to d).

 

Claims (1)

PATENT CLAIM Fungicidal agent which, as the active component, is a phosphoric acid ester of the formula EMI3.1 or the formula EMI3.2 contains.