IL39211A - Fungicidal compositions containing 4-dialkylaminophenylhydrazones of phenyl and naphthyl aldehydes and certain such novel compounds - Google Patents

Description

39211/2 ηιβιπ nia*T023 niaianm ο^ΐ'πι'τ» 'noai ¾*JD 'mtRmnb*ja Fungicidal compositions containing 4-dialkylamino-phenylhydrasonos of phenyl and naphthyl aldehydes and certain such novel compounds BAYER AEPIB GESELLSCHAPT C:37020 A The present invention relates to the use as fungicides of certain 4-dialkylamino-phenylhydraKones, one of which is known, and to some that are new.

It has been disclosed that di hioca bamic acid derivatives can be used for combating phytopathogenic fungi (see U.S. Patent Specification 2,317,765.)· T e zinc salt, in particular, has attained world-wide importance. Nevertheless, the action is not always satisfactory if small amounts are used. It is also known that 4-dialkylamino-phenylhydrazones of 1,2,3-trlearbonyl compounds display a good activity against plant-pathogenic fungi (see Deutsche Auslegeschrift (German Published Specification) 1,133*178 and Deutsche O enlegungechrift (German Published Specification) 1,810,581). However, the latter compounds have too narrow a spectrum of activity for practical purposes.

US Patent Specification 2,818,367 discloses substituted benzaldehyde phenylhydrazones in which the phenyl ring of the benzaldehyde moiety may be substituted with one or two identical or different substituents selected from halogen, nitro, sulfo, hydroxy, alkyl, alkoxy and N-alkylamino. These compounds are effective against cereal rust.

According to Patent Specification 20619 phenyl hydrazones of the formula: X-H-NeCH-I^ R in which X is an aryl radical with up to 10 carbon atoms optionally substituted with alkyl, alkoxy, alkoxyca bonyl, amino mono- or dialkylamino or halogen and X^ may be the same as X, oseesB strong acarlcidal properties. The only active compound specifically mentioned in this specification which bears an alleylamin.o substituent is the dimethylamino-benzaldehyde phenyl hydrazone, 4ττβ. in which the benzaldehyde moiety =CH- ^ in the above formula is substituted. Wo compound i which the phenyl ring X in the above formula is substituted with dialkylamino has been described or exemplified in that specification.

It has now surprisingly been found that the 4-dialkylamino-phenyl-hydrazones of the general formula: in which R and R' are each alkyl with up to 4 carbon atoms (the alkyls being identical or different), R" is hydrogen, lower alkanoyl, alkoxycarbonyl or alkylcarbamoyl, R"1 is hydrogen, halogen, lower alkyl, lower alkox or lower alkanamido, and Ar is an optionally halo, hydroxy, alkylthio, nitro, sulfo or a di-loweralkylamino phenylhydrasono methylene substituted phenyl radical, or an optionally hydroxy substituted naphthyl radical. possess strong fungicidal properties and very wide spectrum of activity.

In the formula (I) it is preferred that R and R' should each be methyl or ethyl? R" should be hydrogen or acetyl; .R*' should be hydrogen, chlorine, me hoxy or methyl; and r should be e r nahth l whi h ma o tionall carr one or more mo hyl» methoicy» methylthioacrcapfro and the HO-SOg-group v;here Ar is the phenyl groupjad hydroxy where Ar 1B the naphthyl group.

The present invention accordingly provides a fungicida composition containing as active ingredient a compound of the formula (I) above in admixture with a solid or liquefied gaseous diluent o carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

The present invention also provides a method of combating fungi which comprises applying to the fungi or ungus habitat a compound of the formula (I) above, alone or in the form of a composition containing as active ingredient a compound of the formula (I) in admixture with a diluent or carrier.

Surprisingly, the ^1al3^1amino-plae yl dra!ao eB that can be used as fungicides according to the present invention show a substantially higher fungicidal action, with a broader spectrum of action, than the phenylhydra¾one eompounds know from the state of the art.

Amogs the compounds that can be used as fungicides according to the present invention, benzaldehyde-4-aimethylamino-phenyl-hydrasone has already been described in th© literature (Journal fiir praktische Chemie 3,22, 151 (1934)), but Its fungicidal action was unknown.

The remainder of the compounds that can be used according to this invention are new and form part of the present invention.

The present invention therefore also provides, as hew compounds, the 4^ialkylamino-pJienylhydrazones of the general formula: In which It, R* , R" and R"' have the same meanings as in formula (I) , Ar* has the same meaning as stated in formula (I) except that when R,T and RM* are both hydrogen Ar* cannot he unsubstltuted phenyl. a The compound of formula (II) can he prepared, in/known manner by reacting 4-dialkyl&mino-phei2ylhydra--ines with aromatic aldehydes i aqueous solution or in organic solvents in a region between neutrality and the acidity of acetic acid.

As examples of ar lhydrazines that are suitable for the reaction there may be mentioneds 4-dletliylajiiino-phenyliiydra2ine, 4-(methyl-ethylamino)■- henylhydrazine , 4-dimethylamino-3-chloro-phenylhydraaine, 4-dimethylamino-3-iaethyl-phenylhydrazine, 4-dlmethylan.ino-2Hnaethyl-phenylhydrazine, 4-dimethylamino-3-methoxy-phenylydrazine and 4-dimethylamino-3-acetamido-phenylhydrazine.

The above-mentioned hydrazine derivatives can be prepared in a known manner (see Journal fttr praktische Chemie 139, 151 (1934)).

As examples of aromatic aldehydes that are suitable for the preparation of compounds of the formula (I), there may be mentioned: 2-, 3- and 4-chloro¾enzaldehydes, 2,4- and 2,6-dichloro-benzaldehydes, 4-bromo-benzaldehyde, 2,4,5-trichloro-benzaldehyde, 3- and 4-nitro-benzaldehydes, 2-chloro-5-nitro-. benzaldehyde, 5-chloro-2-nitro-benzaldehyde, 2-, 3- and 4- thio hydroxy-benzaldehydes, ^-mcfahoxy- end 4-methylmaro^ o-benzaldehydes, 3,5-dichloro-2-hydroxy-benzaldehyde, 3, 5-diiodo-2-hydroxy-behzaldehyde, 4-Hiimethylamino-benzaldehyde, 2- . hydroxy-l-naphthaldehyde, benzaldehyde-2-sulphonic acid, 4-chloro-benzaldehyde-2-sulphonic acid and terephthal-dialdehyde.

The reaction of the 4^ialkylamino-phenylhydrazines -preferably i the form of thei dihydrochlorides - with the aromatic aldehydes can be carried out in water and/or organic solvents, with the addition of acid-binding agents, such as sodium acetate, potassium acetate, sodium carbonate, potassium carbonate, sodium phosphate, triethylamine or urea. The aldehyde 4-dialkylamino-phenylhydrazones are obtained in a crystalline form. They can, if desired, be converted into the N-acyl derivatives by reaction with acylating agents, such as acetic anhydride, propionyl chloride, carbonic acid methyl ester chloride, methylisocyanate and butylisocyanate.

The active compounds of the formula (I) are colourless or only pale yellow in colour; more importantly they show a high fungicidal activity and a broad spectrum of activity and are of relatively low toxicity to warm-blooded animals. As a result, they can be used simply and without exposing the working personnel to objectionable or hazardous conditions, for practical combating of undesired fungal growth. Their good plant diseases, by treating the growing crop plant, individual parts thereof or the seed, or by "Seating the soil in which the crop is grown. The compounds to be used according to this invention are active against parasi ary fungi on above-ground parts of plants, such as varieties of Phytophthora and against fungi that cause tracheomycosis and that attack the plants from the soil, such as varieties of Verticillium, varieties of Fusarium and varieties of Ph.ialoph.or . However they are also active against seed-borne fungi, such as Tilletia tritici. and against fungi that inhabit the soil, such as varieties of Rhizoctonia. Fusarium, Pythlum. Verticillium and Thielaviopsis. It should be particularly emphasised that the active substances to be used according to this invention have a curative action in the case of tomatoes and potatoes attacked by Phytophthora infes ans.

The active compounds according to the present invention can be converted into the usual formulations, such as solutions, emulsions, suspensions, powders, pastes and granulates. These may be produced in known manner, for example by mixing the active compounds with extenders, that is liquid or solid or liquefied gaseous diluents or carriers, optionally with the use of surface-active agents, that is, emulsifying agents and/or dispersing agents. In the case of the use of water as an extender, organic solvents can, for example, also be used as auxiliary solvents.

As liquid diluents or carriers, there are preferably used aromatic hydrocarbons, such as xylenes, toluene, benzene or alkyl naphthalenes, chlorinated aromatic or aliphatic hydrocarbons, such as chlorobenzenes, chloroethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or butanol or glycol as well as their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, or strongly polar solvents, such as dimethyl-formamide, dimethyl sulphoxide or acetonitrile , as well as water* By liquefied gaseous diluents or carriers are meant liquids which would be gaseous at normal temperatures and pressures, for example aerosol propellents, such as halogenated hydrocarbons, for example freon* As solid diluents or carriers, there are preferably used ground natural minerals, such as kaolins, clays, talc, chalk, quartz, tapulgite, montmorillonite or diatomaceous earth, or ground synthetic minerals, such as highly-dispersed silicic acid, alumina or silicates* Preferred examples of emulsifying agents include non-ionic and anionic emulsifiers, such as polyoxyethylene-fatty acid esters, polyoxyethylene-fatty alcohol ethers, for example aIk larylpol glycol ethers, alkyl sulphonates, alkyl sulphates and aryl sulphonates| and preferred examples of dispersing agents include lignin, sulphite waste liquors and methyl cellulose.

The active compounds of "the formula (I) may be present in the formulations in admixture with other active compounds, for example other fungicides, insecticides, acaricides and nematocides, as well as fertilisers and agents for improving soil structure.

The formulations contain^ in general, from 0.1 to 95$ preferably from 0»5 to 90 by weight of active compound.

The active compounds can be used as such, in the form of their formulated compositions or in the application forms pre suspensions, powders, pastes or granules . They may be used in any customary manner^ for example by squirting, spraying, atomising, sprinkling, dusting, pouring, dry dressing, slurry dressing, moist dressing or wet dressing.

In the case of seed dressing, amounts of active compound of from 0.01 g to 10 g, preferably from 0.05 to 5 g, are generally employed per kilogram of seed. In the case of soil treatment, which can be carried out by overall, band or spot treatment, concentrations of 'from 1 to 500 g, preferably from 10 to 200 g, of active compound per or of soil, are generally required at the location of the desired action.

For general purposes, especially where above-ground parts of plants are to be treated* the active-compound concentrations in the applied compositions are from 0.001 to 3 per cent by weight, preferably from 0e002 to 1 per cent by weight.

The present inde tio further provides crops protected from damage by fungi by being grown in areas in which immediately prior to and/or during the time of the growing a compound of the formula (I) was applied alone or in admixture withe diluent or carrier. It will be seen that the usual methods of providing a harvested crop may be improved by the present invention.

The compounds that can be used according to this invention also possess a microbicidal action. Furthermore, they display an insecticidal and acaricidal action.

The activity of the compounds of the formula (I) is illustrated in and by the following test Examples.

Example A Phytophthora test Solvents 4«7 parts by weight acetone Water: 95 parts by weight The amount of the active compound required for the desired concentration of the active compound in the spray liquid is mixed with the stated amount of solvent and the concentrate is diluted with the stated amount of water which contains the stated additions .

Young tomato plants (Bonny best) with 2-6 foliage leaves are sprayed with the spray liquid until dripping wet. The plants remain in a greenhouse' for 24 hours at 20°C and at a relative atmospheric humidity of 70?oa The tomato plants are then inoculated with an aqueous spore suspension of Phytoph-thora infestans . The plants are brought into a moist chamber with an atmospheric humidity of lOOfo and a temperature of 18° - 20°Ce After 5 days, the infection of the tomato plants is determined as a percentage of the untreated but likewise inoculated control plants: 0 means no infection; 100 means that the infection is exactly as great as in the case of the control plants .

The active compounds, the concentrations of the active compounds and the results can be seen from the following Table: Table A Phytophthora Test Attack in of the attack of the untreated control at an active compound concentration of S Table A (continued) Phytophthora Test Attack in ° of the attack of the untreated control of an active compound concentration of Active compound 0.0062 0.003136 (7) Table A (continued) Phytophthora Test Attack in of the attack of the untreated control at an active compound concentration of Active compound 0.0062 0.0051 (19) Table A (continued) Phytophthora Teat Attack in of the attack of the untreated control at an active compound concentration of Active compound 0.0062# 0.0031 (10) Example B Phytophthora teat/curative Solvent: 4.7 parta "by weight acetone Emulsifier: 0.3 parts "by weight alk larylpolyglycol ether Water: 95 parts by weight The amount of active compound necessary for the desired concentration of active compound in the preparation mixture is mixed with the stated amount of solvent, and the concentrate is diluted with the stated amount of water which contains the said additions.

From tomato plants (Bonny Best variety) pinnules are removed and these are laid with the top side facing upwards in Petri dishes the lids and bottoms of which are provided with moist filter paper. The pinnules introduced are sprayed with an aqueous spore suspension of Phytophthora infestans and incubation is effected in closed dishes for 6 hours at 20°C. The leaves are subsequently immersed in the preparation mixture prepared according to the above process. The Immersion time After a further incubation of.3 days at 20 C in a closed dish, the infection on the treated pinnules is determined as a percentage of the infection of the untreated but likewise inoculated pinnules (= control). Qffo means no infection; 100 means that the infection is exactly as great as in the case of the control.

The active compounds, the concentrations of the active compounds and the results can be seen from the following Table : Table B Phytophthora Test/curative Attack in # of the attack of the untreated control at an active compound Active compound concentration of 0.025$ s (known) (18) (1) 33 Table B (continued) Phytophthora Test/curative Attack in fo of the attack of the untreated control at an active compound Active compound concentration of 0.025 Table B (continued) Phytophthora Test/curative Attack in.jS of the attack of the untreated control at an active compound concentration of 0.025$ Example C Agar plate test Test for fungitoxic effectiveness and breadth of the activity spectrum.

Solvent : acetone Parts by weight: 100 To produce a suitable preparation of the active compound, 1 part by weight of the active compound is taken up in the stated amount of solvent.

The preparation of the active compound is added to potato dextrose agar (which has been liquefied by heating) in such an amount that the desired concentration of active compound is set up therein. After thorough shaking to achieve a uniform dispersion of the active compound, the agar is poured into Petri dishes under sterile conditions. When the mixture of substrate and active compound has solidified, test fungi from pure cultur.es are inoculated on to it in small discs of 5 mm diameter. The Petri dishes remain at 20°C for 3 days for incubation.

After this time, the inhibiting action of the active compound on the mycelium growth is determined in categories, taking into account the untreated control. "0"means no mycelium growth, either on the treated substrate or on the inoculum; the symbol" means mycelium growth on the inoculum only, no spread to the treated substrate? and the symbol" +" means mycelium growth from the inoculum on to the treated substrate, similar to the spread to the untreated substrate of the control.

The active compounds, the concentration of the active compounds, the test fungi and the inhibition effects achieved can be seen from the following Tables Le A 13 580 - 16 - Table C Agar Plate Test Active compound concentration in the substrate9 Active compound in mg per litre Untreated S (known) 100 (18) Table C (continued) Agar Plate Test Active compound concentration in the substrate , Active compound in mg per litre Table C (continued) (8) 100 (11) o Example D Seed dressing test/bunt of wheat (seed-borne mycosis) To produce a suitable dry dressing, the active compound is extended with a mixture of equal parts by weight of talc and kieselguhr to give a finely powdered mixture with the desired concentration of the active compound.

Wheat seed is contaminated with 5 g of the chlamy-dospores of Tilletia tritici per kg of seedc To apply the dressings, the seed is shaken with the dressing in a closed glass flask. The seedg on moist loam under a cover of a layer of muslin and 2 cm of moderately moist compost soil, is exposed to optimum germination conditions for the spores for 10 days at 10°C in a refrigerator..

The germination of the spores on the wheat grains, each of which is contaminated with about 100,000 spores, is subsequently determined microscopically. The smaller the number of spores which have germinated, the more effective is the active compound.

The active compounds, the concentrations of the active compounds in the dressing, the amounts of dressing used and the percentage spore germination can be seen from the following Tables Tahle D Active compound concen= Amoun tration in the Active compound ing, in f by we Without dressing S is (known) 10 s . (3 ) 30 Table D (continued) Seed Dressing Test/Bunt of Wheat Active compound concen- Amount tration in the dress- used, ing, in by weight seeds Table D (continued) VJ4 Seed Dressing Test/Bunt of Wheat tration in the dress- used, Active compound ing, in by weight seeds HH-N-CE (10) 30 The known benzaldehyde-4—dimethyla ino-phen lhydrazone can "be prepared in accordance with the instructions in the literature (Journal fur praktische Chemie 1391 151 (1954)). The new compounds are obtained in a manner that is similar in principle; the preparation of these compounds is illustrated in and by the following Examples.

Example lg 24 g (0.17 mol) of 4-chloro-benzaldehyde are dissolved in 200 ml of methanol,, the solution is added to 50 ml of a saturated sodium acetate solution, and 40 g (0.18 mol) of freshly prepared 4^i^th lamino~phenylhydrazine dihydro-chloride are introduced at 0° to 5°C, with strong stirring. After 15 minutes, the mixture is diluted with 500 ml of water, sufficient aqueous ammonia solution is added dropwise to give a pH value of 8, and the product is filtered off and washed with water and methanol. After drying in vacuo, 37 g (0.135 mol) of 4-chloro-benzaldehyde^4^in»thylamino<-phenylhydrazone are obtained as a pale yellow crystalline powder of melting point 135°C (with decomposition) .

The following compounds of the general formula are obtained by methods analogous to that of Example 1.

Example ArM No. represents Melting point (°C) ion) ion) ion) ion) ion) ion) ion) ion) tion) Example Ar" No. represents Melting point (°C) sition) Example 15 ' g (0.17 mol) of sodium benzaldehyde-2=sulphonate are dissolved in 600 ml of water, the solution is added to 50 ml of a saturated sodium acetate solution, and 40 g (0.18 mol) of freshly prepared 4-dime h lami o-=phenylhydrazine dihydrochloride are introduced at 0° to 5°C. Hereupon, the condensation product very largely precipitates as a grey crystalline powder. Sufficient aqueous sodium carbonate solution is added dropwise to give a pH value of 7 and the product is then filtered off, washed with water and dried in vacuo. 41 g (0.128 mol) of 2»sulphobenzaldehyde/4-dimethylamino-phenylhydrazone are obtained as a light grey crystalline powder of melting point 202° - 203>°C (with decomposition). The yield is 7 of theory.

Example 16; described in Sxample 15. Melting point 185°C (with decomposition) .

Example 17: 22.5 g (0.168 mol) of terephthal-dialdehyde are dissolved in 200 ml of methanol, 100 ml of saturated aqueous sodium acetate solution and 200 g > ice are added and 85 g (0.38 mol) of freshly prepared 4-dimethylamino-phenylhydra-zine dihydrochloride are then introduced at 0°C whilst stirring well. After 15 minutes the mixture is diluted with 1 litre of water and the product is filtered off, rinsed with water and methanol and dried in vacuo. 56 g (0.14 mol) of terephthal-dialdehyde bis-(4-dimethylamino-phenylhydrazone) of melting point 215°C (with decomposition) are obtained. The yield is 83$ of theory.

Claims (44)

39211/2 - 29 - CI.AII¾3

1. A fungicidal composition comprising as active ingredient a 4^ialkylamino-pheijylhydra3one of the general formula R"f in which R and R* are each alkyl with up to 4 carbon atoms (the alkyl£l being identical or different, R" is hydrogen, lower alkanoyl, alkoxycarbonyl or alkylcarbamoyl, R°' is hydrogen, halogen, lower alkyl, lower alkoxy or lower alkanamido, and Ar is an optionally halo, hydroxy, alkylthio, nitro, sulfo or a di-loweralkylamino phenylhydrazono methylene sitetituted phenyl radical, or an optionally hydroxy substituted naphthyl radical, in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluat or carrier containin a surfaces-active agent.

2. A fungicidal composition containing as active ingredient a compound of the formula in Claim 1, in which R and R' are each methyl or ethyl; Rn is hydrogen or acetyl; R"» is hydrogen, chlorine, raethoxy or methyl; and Ar is phenyl optionally carryin at least one s bstitu^nt selebed from halogen, hydroxy, nitro, mothyl, mo-tfaogy, methylthio and the HO-SGg- group or a hydroxy naphthalene group; in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent a ai a surface-active agent.

3. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

4. fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

5. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

6. A fungicidal composition containing as active ingredient a compound of the formula. in admixture with, a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

7. A fungicidal, composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

8. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or. liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

9. fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

10. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

11. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

12. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

13. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

14. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

15. fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

16. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

17. A fungicidal composition containing as active ingredient a compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

18. A composition according to any of claims 1 to 17 containing from 0.1 to 95$ of the active compound, by weight.

19. A composition according to claim 18 containing from 0.5 to 90j¾ of the active compound, by weight.

20. A method of combating fungi which comprises applying to the fungi or a fungus habitat a compound of the formula given in any of claims 1 to 17 alone or in the form of a composition containing as active ingredient a compound of the formula given in any of claims 1 to 17 in admixture with a diluent or carrier.

21. A method according to claim 20 in which a composition is used containing from 0.001 io 3$ of the active compound, by weight .

22. A method according to claim 21 in which a composition is used containing from 0.002 to of the active compound, by weight .

23. A method according to any of claims 20 to 22 in which the active compound is applied to seed in an amount of 0.01 g to 10 g per kg of seed.

24. method according to claim 23 in which the active compound is applied in an amount of 0.05 g to 5 g per kg of seed.

25. A method according to any of claims 20 to 22 in which the active compound is applied to soil in an amount of 1 g to 500 g per m of soil.

26. A method according to claim 25 in which the active compound is applied io. an amount of 10 g to 200 g per m of soil.

27. method according to any of claims 20 to 26 in which the according to Claim 1 active compound As one of those hereinbefore mentioned in any of Examples A to D.

28. Crops protected from damage by fungi by being grown in areas in which immediately prior to and/or during the time of the growing a compound of the formula given in any of claims 1 to 17 was applied alone or in admixture with a diluent or 39211/2

29. The 4-dialkylamino-phenylhydrazones of the general formula in which R, Rv, R" and R,M have the meanings stated in Glaim 1, and Ar' has the same meaning as in Claim 1 except that when R" and R1" are both hydrogen Ar' cannot be unsubstituted phenyl.

30. The compound" of the formula

31. The compound of the formula

32. The compound of the formula

33. The compound of the formula

34. The compound of the formula

35. The compound of the formula

36. The compound of the formula

37. The compound

38. The compound of the formula

39. The compound of the formula

40. The compound of the formula

41. The compound of the formula 5111/2

42. The compound of the formula

43. The compound o e ormu a

44. The compounds according to C aim 29 substantially described herein with reference to the Examples.