CS212786B2 - Composition for protecting plants against frost - Google Patents

Abstract

To protect plants against frost damage, the plants, or parts of plants, to be protected are treated before the incidence of frost or the beginning of winter with a composition which contains, as the ingredient which imparts frost resistance, a hydroxamic acid derivative of the formula <IMAGE> in which R1 is optionally substituted C3-C17-alkyl or C5-C7-cycloalkyl or optionally substituted phenyl and R2 and R3 in each case denote hydrogen, C1-C5-alkyl, alkylcarbonyl or arylcarbonyl, but in which R3 can also be the equivalent of a metal, ammonium or quaternary ammonio cation. The process and the composition are particularly suitable for protecting fruit plantations, vegetables and ornamentals, the preferably used hydroxamic acid derivatives being t-C4H9-CO-NHOH and CH3(CH2)4-CO-NHOH.

Description

The present invention relates to a composition for the protection of plants against damage caused by frost, in particular for the protection of crop plants such as fruit trees, vegetables, ornamental plants, including shrubs and trees.

Preventing frost damage to crops is an extremely important problem in agriculture and horticulture. Numerous active substances and various measures have therefore already been proposed to increase the resistance to frost, i.e. to increase the resistance of crops and ornamental plants to the effects of cold and frost, and to prevent damage caused in this way. In addition to the use of polymers, foams and mists, this often involves the use of substances which are protective agents against the freezing of plant cells caused by membrane damage. These frost damage are often caused by irreversible changes in the cell membrane structure and its associated proteins, such as changes in permeability, leading to the breakdown of vital cell functions such as oxidative phosphorylation.

Numerous preservatives have been proposed to freeze cells, but not all of them satisfactorily, since their applicability is limited to certain plants or has phytotoxic side effects. .....

Growth regulators have also been proposed which reduce plant metabolism and reduce vegetative activity and thus keep the plant at rest, making it much less sensitive to frost.

Hydroxamic acids and their derivatives have not been proposed from numerous plant protection agents against frost.

It has now surprisingly been found that the hydroxamic acid derivatives of the general formula (I)

Rt = co — N — O — R3

R2 (I), optionally the tautomeric formula (Ia)

R1-C = N-O-R3

AND

O — Ri (Ia) in which

R1 represents an unsubstituted or chloro-substituted alkyl radical having 1 to 17 carbon atoms, a cycloalkyl radical having 3

212788 to 6 carbon atoms or a phenyl moiety which. Yippee. optionally substituted once to twice with methyl, chloro and / or methoxy;

R2 is hydrogen or (C1-C4) -alkyl,

R3 is. hydrogen, methyl, C 1 -C 11 alkylcarbonyl, straight or branched chain alkyl, phenylcarbonyl, p-chlorophenylcarbonyl, methylcarbnoyl, or a metal, amine or cation equivalent. quaternary ammonium groups; and

R 4 is hydrogen, C 1 -C 4 alkyl. carbon, phenylcarbonyl, or p-chlorophenylcarbonyl, with excellent results. way. They are useful as active ingredients of agents for the protection of crop plants against frost, especially fruit tree cultures. (peach trees, peach trees, peach trees, apple trees, etc.) but also various types of vegetables, ornamental plants, including shrubs and. of trees.

The subject of this. The invention is therefore a plant protection agent against frost damage, characterized in that it contains at least one active ingredient. a hydroxamic acid derivative of the formula I or a tautomeric formula Ia. ........

Suitable metal cations in the meaning of R3 are, in particular, alkali cations. metals and metals. alkaline earth but also trace elements,. such as cations of copper, iron and manganese.

Protection of crop plants against damage caused by frost is carried out by:. se. plants or parts of plants to be protected. before the winter, or the expected frost, will be treated. means,. which. contains a derivative. . hydroxamic '. of the acid. I,. optionally. Ia at an effective concentration.

Effectively.'. substances of the formula. I. and '. Ia provide extensively. long-lasting. protective effect that lasts until spring when applied in autumn. The protective effect occurs immediately, so that the treatment carried out the day before the frost comes, already provides safe protection against frost damage.

Preferably, active compounds of the formula I are used in which:. R 1 represents an alkyl radical having from 3 to 8 carbon atoms; phenyl radical, R 2,. optionally R 4 is hydrogen or methyl and R 3 is hydrogen, one of said cations or methyl. a C 1 -C 11 alkylcarbonyl radical or a phenylcarbonyl radical.

Most of the active compounds of the formulas I 'and Ia are known compounds and are further described, for example, in Houben-Weyl, Vol. 8, pp. 684-692; Beilstein. St. 9, p. 341 and in other literature. These are compounds which are stable in water and in customary organic solvents. they are soluble.

Some hydroxamic acid derivatives of the above type have already been suggested as herbicides and fungicides and as growth promoters in veterinary medicine (see, for example, U.S. Patent No. 3,714,361). Several representatives. Phytotoxic side effects may occur from this class of active substances. In this case, it is recommended to optimize the frost-to-side protection effect by additional measures (dose selection, etc.). phytotoxic effect.

Certain hydroxamic acid derivatives exhibit properties exhibiting the ability to control plant growth, such as. is the inhibition of growth and stimulation of fetal or leaf abscess.

Alkyl radicals in the meaning of symbols. . R 1 to R 4 may have a straight chain or a chain. branched.

Further .. are. listed. effective. substances,. serving as. Examples for derivatives. acid. hydroxamic formulas. AND

R 1 -CO-N-O-R 3;

(I) which are applicable according to. invention:

Compound No. Ri .. R2 Rs Physical data Melting point. ° C) 1 CHs (CH2) 4- H H 63 to 65 2 C6H5- H -COC6H5 59 to 61 3 cyclohexyl H H 130 4 n-C 8 H 17 H H 76 to 77 5 n-C 11 H 23 H H 90 to 99 6 П-С17N35 H H 90 7 te.rc.c4H9 Ή H 167 to 168 8 C6H5 H H 127 to 129 9 CH3O — CsH4- 1 H H 160 to 163 10 CH ₃ (CH ₂ ) 4 H H 67 to 69 11 Π-Ο ^ Ηγ H K + amorphous substance 12 п-СбШз H H 42

Compound c.

21278.6

Ri R2 R3 Physical data melting point [° C] П-С4Н9 Ή H H-C7H15 <H H 79 CHs (CH 2) 3 - CH - iH H CH3 t.erc.C4H9 H hn® (C2HiOH) 3 CH3 \ CH- [CH 2] 3 - H H / CH3 cyclopentyl H H C1- (CH2) 5- iH H m-chlorophenyl iH H o-tolyl H H 2-methyl-4-chlorophenyl iH H CH3 (CH2) 4- -C2H5 H CH5 [CH 2] 4- CH3 CH3 CH3 (CH2) 4- H HN ® [[CH 2) 2 OH] 3 CH3 (CH2) 4- H HN® (C2H5) 3 target. Cd H9 H K © > 250 t-erc.Carfo : H —CO — CH3 114 to 116 n-CsHiu CH3 CHs boiling point 96 ° C / 1463 Pa t-erc.CdHg CH3 CHs boiling point 62 ° C / 1596 Pa n-CsHn H —COCH3 76 to 79 terc.CaHg H ¹ Fe +++ 3 > 270 1S0-C3H7 H H 116 t-C 4, H 9 H CH3 n _D 20 = 1.4439 terc.C4H9 H —CONHCH3 90 n-C4H9 H —COCH3 62 to 65 Cl- (CH2) 3- CHs CH3 boiling point 113 ° C / 1729 Pa ý- H K + 114 to 117 [b H H 116 terc.CdH9 H —CO-t-CdHg 147 to 148 CH5 (CH2) 3 —CH— H 2 CU + * > 200 C2H5 p-toluidyl H H 143 to 144 2,4-dlchlorophenyl H H 158 to 159 CHs H I-I 87 to 89 C2H5 H H 68 to 69 CICH2- H H 85 to 90 terc.C4H9 H —CO — C3H9 105 to 106 terc.CdPL · H —CO — C11H23 (n) 35 to 38 terc.C4H9 H -co- ^θ- 122 to 124 n-C4H9 H H n-C3H7 — CH— H H

CH3

Compound · No. Ri Rz R3 Physical data melting point rc) 52 ISSO-C4H9 H H 72 to 75 53 n-C4Hg — CH— H H | C2H5 C2H5 \ 54 CH— H H / C2H5

'Tautomeric' hydroxamic acid derivatives of formula Ia

R1-C = N-O-R3

AND

O — R4 (Ia)

R3 R4

Compound RI no

Physical data

55 n-CsHii CH3 CHs boiling point 70 ° C / 5320 Pa 56 phenyl H C2H5 melting point Mp 60-65 ° C 57 CHs H C2H5 mp 25-26 ° C 58 terc.CdH9 -cc ^ O- ^{-ct -co} ^ -f ^ —ct 59 terc.CdHto —CO-phenynyl —CO-phenyl melting point

to 102 ° C

Suitable carriers and additives in the compositions of the invention may be solid or liquid and correspond to conventional substances in such compositions as natural or regenerated minerals, solvents, dispersants, wetting agents, thickeners, adhesives, binders or fertilizers.

For application, the compounds of formula I may be present in the following processing forms:

solid forms of processing:

dusting, spreading, microgranules; Liquid processing:

(a) water-dispersible concentrates of the active substance: wettable powders, pastes, emulsions;

(b) solutions.

In order to prepare solid processing forms (dusting, spreading), the active compounds are mixed with solid carriers. Suitable carriers are, for example, kaolin, talc, bolus, loess, chalk, limestone, crushed limestone, attapulgite, dolomite, diatomite, precipitated silicic acid, alkaline earth metal silicates, aluminum-potassium and aluminum-potassium silicates (feldspars and mica), calcium sulphate and magnesium sulphate, magnesium oxide, ground plastics, fertilizers such as · ammonium sulphate, ammonium phosphate, ammonium nitrate, urea, ground vegetable products such as · cereal flour, tree bark meal, wood meal, nut shell meal, powdered cellulose,. plant extract residues, activated carbon, etc., either alone or in admixture with each other.

Polymeric granulated granules can be prepared by impregnating, for example, their ready-to-use, porous polymer-based granules (urea-formaldehyde, polyacrylonitirile, polyester and others) with a certain surface area and favorable predetermined absorption and desorption ratios. in a low boiling solvent) and the solvent is removed. Such polymer granules can also be applied in the form of microgranules with a bulk density preferably from 300 g / liter to 600 g / liter also by means of sprayers. Spraying can be performed over aircraft over large areas to be treated.

Granules may also be obtained by compressing the carrier with the active ingredients and additives and comminuting.

In addition, active ingredient stabilizing agents and / or non-ionic, anionic and cationic agents may be added to these compositions, for example to improve the adhesion of the active ingredients to plants and plant parts (adhesives and adhesives) and / or to provide better wettability (wetting agents) as well as dispersibility (dispersants).

For example, the following substances are suitable: a mixture of olein and lime, cellulose derivatives (methylcellulose, carboxymethylcellulose), hydroxyethylene glycol ethers of mono- and dialkylphenols having 5 to 15 ethylene oxide groups per molecule and 8 to 9 carbon atoms in the alkyl residue, ligninsulfonic acid, its salts with alkali metals and alkaline earth metals, polyethylene glycol ethers, carbonyl waxes, polyglycol ethers of fatty alcohols having 5 to 20 ethylene oxide groups per molecule and 8 to 18 carbon atoms in the rest of the fatty alcohol, condensation products of ethylene oxide, propylene oxide, polyvinylpynrolidones, polyvinyl alcohols, urea-formaldehyde condensation products as well as latex products.

The water-dispersible active ingredient concentrates, ie wettable powders, pastes and emulsion concentrates, are compositions which can be diluted with water to any desired concentration. They consist of an active ingredient, a carrier, optionally active ingredient stabilizers, surfactants, antifoams and solvents.

Wettable powders and pastes are obtained by mixing the active ingredients with dispersants and powdered carriers in suitable equipment to form a homogeneous mixture, and grinding them. Suitable carriers are, for example, those mentioned above for solid processing forms. In many cases, it is advantageous to use mixtures of different carriers. The following can be used as dispersants, for example: condensation products of sulfonated naphthalene and sulfonated naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalenesulfonic acid with phenol and formaldehyde, as well as alkali metal, ammonia and alkaline earth metal salts of ligninsulfonic acid, alkylarylsulfonates, alkali metal and alkaline earth metal salts of dibutylnaphthalenesulfonic acid, sulfated fatty alcohols such as sulfated hexadecanols, heptadecanols, octadecanols, and sulfated fatty alcohol glycol ethers, sodium oleylmethyltauride sodium, di-tertiary ethylene glycol di-ethylene glycol salts alkali metals and alkaline earth metals.

Suitable antifoams are, for example, silicone oils.

The active ingredients are mixed, ground, sieved and sieved so that the solids do not exceed a particle size of 0.02 to 0.04 for wettable powders and 0.03 mm for pastes. In the preparation of emulsion concentrates and pastes, dispersants as mentioned in the above paragraphs, organic solvents and water are used. Suitable solvents are, for example, alcohols, aromatic hydrocarbons of lower freezing point (below -20 ° C), such as o-xylene, m-xylene, toluene and mineral oil fractions boiling in the range of from 120 ° to 350 ° C. The solvents should be practically odorless, non-phytotoxic and inert to the 'active ingredients'.

Furthermore, the compositions of the invention may be used in the form of solutions. For this purpose, the active compound or compounds of the formula I are dissolved in suitable organic solvents or low-freezing solvent mixtures. The organic solvents ¹ used may be aliphatic and aromatic hydrocarbons, their chlorinated derivatives, alkylnaphthalenes, mineral oils, alone or in admixture with each other.

The active compound content of the above-described compositions is between 0.1 and 95%, preferably between 1 and 80%. The dosage forms can be diluted to the desired concentration.

The active compounds of the formula I can be formulated in compositions, for example, as follows:

Dust: ......

For the preparation of (a) 5o / ₀ and (b) 2% dusts, the following substances are used:

(a) 5 parts of active substance, parts of talc;

(b) 2 parts of active substance, part of highly dispersed silicic acid, parts of talc.

The active compounds are mixed with the carriers and the mixture is ground.

Granulate:

The following substances are used to prepare 5% granulate:

parts of the active substance,.

0.25 parts of epichlorohydrin,

0.25 parts of cetyl polyglycol ether,

3.50 parts of polyethylene glycol, parts of kaolin [part size 0.3-0.8 mm].

The active ingredient is mixed with epichlorohydrin and dissolved in 6 parts of acetone. Polyethylene glycol and cetyl polyglycol ether are then added. The solution thus obtained is sprayed onto kaolin and then the acetone is evaporated in vacuo.

Wettable powder:

In order to prepare a) 70%, b) and c) 25% and d) 10% wettable powder, the following ingredients are used:

(a) 70 parts of active substance, parts of sodium ligninsulphonic acid, parts of sodium dibutylnaphthalenesulphonic acid, parts of silicic acid;

(b) 25 parts of active substance,

4.5 parts of lignin sulphonic acid calcium salt,

1.9 parts of a mixture of chalk (prov. - Champagne) and hydroxyethylcellulose (1: 1),

1.5 parts of sodium dibutylnaphthyl sulfonate,

19.5 parts of silicic acid,

19.5 Chalk (Champagne),

28.1 parts of kaolin;

C) 25 parts of active substance,

2.5 parts of isooctylphenoxypolyoxyethylenethanol,

1.7 parts of a mixture of chalk (made by Champagne) and hydroxyethylcellulose (1: 1),

8.3 parts of sodium aluminum silicate,

16.5.

- parts of kaolin;

(d) 10 parts of active substance;

- parts of a mixture of sodium salts of saturated sulphated fatty alcohols, parts of a condensation product of naphthalenesulphonic acid and formaldehyde, 82 parts of kaolin.

The active ingredients are intimately mixed with the ingredients in suitable mixers and ground in appropriate mills and rollers. A wettable powder is obtained which can be diluted with water to suspensions of any desired concentration. Such suspensions are very suitable for treating plants to influence growth and development.

Emulsifiable concentrates:

For the manufacture of the 25o / o emulsifiable concentrate, the following substances are used:

2'5 parts of active substance,

2.5 parts of -oxidized vegetable oil, parts of a mixture of alkylarylsulfonate and polyglycol ether -fat -alcohol, parts of -dimethylformamide,

57.5 parts xylene.

Emulsions of any desired concentration can be prepared from such concentrates by dilution with water. Such suspensions are suitable for application to plants to inhibit growth.

It is particularly advantageous to use the active compounds in the form of dusts, dusts, wettable powders and emulsifiable concentrates, as well as freeze-resistant solutions and -erosols.

The compounds of formula I, which are taken up by plants and are not too early metabolized, induce a slight inhibition of growth, without being appreciably phytotoxic, therefore best responding to the expectations which can be placed on the antifreeze agents.

The frost protection effect of the compositions of the invention was determined and evaluated according to the following experiments:

1. Frost-resistance test of beans

Felix bean plants are grown

in the greenhouse in earthen pots and when they start to bloom - they are sprayed with aqueous preparations containing the following active substances. Active substance concentration in spraying the suspension is 1000 ppm. On one- no treatment is sprayed with 18 plants. Untreated plants are kept as a control. 7 days after application, the test plants are placed in an air-conditioned room where the temperature slowly drops to -1 ° C, then left at this value for a short time, and then the room. slowly rise again to temperature 10 days after this cold treatment, evaluation was made by assessing each plant for frost damage. The -se rating is performed using the following scale: - = all the plants have died (as review) [+] = 1 • intermediate stages of damage + + =. + ++ = all plants without any damage - frost. Results: Compound Protective effect against frost number 1 (+) 2 í +) 4 (+) 7 4- + 8 + 10 + 11 + 28 . _1_ 31 + 34 (+) 35 (+) 36 + 4- 37 (+) 38 + 39 + 4- 40 +

In another experiment, the bean plants were treated twice with a formulation containing Compound No. 1 as the active ingredient, and a) twice at a concentration of 100 ppm and b) twice at a concentration of 500 ppm. One week after the second treatment, the plants are subjected to a temperature of -4 ° C for 1 hour and then grown again under normal conditions.

One week thereafter, the experiment is evaluated. While untreated bean plants were 100%, i.e. totally damaged, the plants treated with the active ingredient at a concentration of 1θ0 ppm ¹ 40o / frost damage and the plants treated with the active ingredient at a concentration of 500 ppm showed only 15% frost damage.

2. Test for resistance to frost damage of citrus plants

One day before the frost, as predicted by the weather forecast, lemon trees are treated with Compound # 1 at the concentration indicated below. The following night, the temperature dropped to -3 ° C for 4 to 5 hours.

days later, the following damage results were detected:

Compound No. 1

Spray suspension treatment (ppm)

Orange Oranges Hamlin and Valencia- and% damage to old leaves newly grown flowers leaves

500 0 80 60 1000 0 70 60 1500 0 70 60 untreated 0 90 90

3. Frost resistance tests of fruit cultures

and)

For this purpose, a device (cage) was used which allowed the perennial branches of the pear tree to artificially induce freezing conditions. Compound No. 1 was applied by spraying on the flowering branches of pear trees at a time when the flowers were just ready to open, i.e. at the time of highest sensitivity to frost. A few days after this spray treatment, part of the treated and untreated larger of the same tree was enclosed by a cage and was artificially induced overnight in that cage, a frost with a minimum temperature of -3 ° C. A few days later, frost damage to the flowers was detected by microscopic examination, with the following results:

treatment with Compound No. 1 at a concentration

2000 · ppm ·· = 74% damage, treatment with compound 1 at concentration

4000 ppm = 26% damage, untreated branches = 97% damage.

(b)

In autumn, just as the leaves turn color and begin to die, the peach trees are sprayed with a liquid formulation containing Compound No. 1 as the active ingredient. In January, the branches are then collected and subjected to cold for 24 hours, with temperature gradually decreases by 2 ° C per hour to a minimum temperature of -21 ° C and then increases again. Two days later, many buds (fetuses) are examined microscopically to determine how many have died and how many have survived - low temperature.

Result:

% surviving buds treatment 1000 ppm 74% treatment 2000 ppm 83 '% treatment 8000 ppm 88% untreated 63%

4. Frost resistance test for peas

The pea seeds ('gloire du · midi') are sown in 60 x 40 cm seed boxes filled with soil. Each cupboard contains 64 seeds. After 14 days after sowing, when the emerging pea plants reach a height of about 15 to 20 cm, half of the plants in each cabinet (32) are treated until water is sprayed off. containing the following active substances in a concentration of 1000 · ppm. The remaining 32 plants in each cabinet are left untreated and serve as co-control. 7 days after treatment, all test plants are placed in an air-conditioned chamber in which the temperature is gradually lowered to -5 ° C and maintained at this value for 14 hours (overnight). The temperature is then slowly raised again to room temperature.

Evaluation of the results is carried out 8 days after this, · cooling, either by visual evaluation and · by expressing the results using the same scale as in Test 1 (on bean), or by detecting · fresh weight of untreated and treated plants in each cabinet.

Results:

A. Visual assessment

Compound Frost protection number *

3 4- 7 + + 11 + 12 + 16 + 27 Mar: 4-4- 28 + 30 (+) 31 + 32 + 33 + 34 (+) 38 ++ 39 ++ 40 4- 41 4-

Compound Frost protection number no

44 ++ 45 (+) 46 + 48 + 52 (+) 55 (+) 57 +

B. Determination of fresh weights (for some selected test compounds)

Increase fresh weight

Compound of number-sprayed pea plants, relative to untreated frost-damaged plants (after 8 days)

4-39%

4- 56%

4-64 ° / o

Claims (5)

OBJECT OF THE INVENTION Composition for the protection of plants against damage caused by frost, characterized in that it contains as an active ingredient at least one hydroxamic acid derivative of the general formula I R 1 —CO — N — O — R 5 R 2 (I) or tautomeric formula Ia R1-C = N-O-Rs AND O — R4 (Ia) wherein R 1 represents an unsubstituted or chlorine-substituted alkyl radical having 1 to 17 carbon atoms, a cycloalkyl radical having 3 to 6 carbon atoms or a phenyl radical optionally substituted once or twice with methyl, chlorine and / or methoxy, R2 is hydrogen or (C1-C4) -alkyl, R 3 is hydrogen, methyl, C 1 -C 11 alkylcarbonyl, straight or branched chain alkyl, phenylcarbonyl, p-chlorophenylcarbonyl, methylcarbamoyl, or a metal, amine or quaternary ammonium cation equivalent, and R a is hydrogen, C 1 -C 4 alkyl, phenylcarbonyl or p-chlorophenylcarbonyl. 2. A composition according to claim 1, wherein the active ingredient comprises at least one compound of formula I or Ia in which: R 1 represents a straight or branched (C 1 -C 7) alkyl radical or a cyclopropyl radical, R2 is hydrogen or methyl, R3 is hydrogen, methyl, C1-C4alkylcarbonyl, or an alkali metal cation; and R4 is hydrogen or methyl. 3. A composition according to claim 1 or 2, characterized in that it contains at least one hydroxamic acid derivative of the formula I or Ia, in which R1 represents a phenyl radical or a straight or branched alkyl radical of 3 to 7 carbon atoms or a cyclopropyl radical. R 2 and R 4 are respectively hydrogen or methyl, R 3 is hydrogen, methyl, an alkali metal cation or a (C 1 -C 4) alkylcarbonyl radical, or a phenylcarbonyl radical. 4. A composition according to claim 3, characterized in that as; the active ingredient comprises n-pentanecarbonylhydroxamic acid of the formula СЩ (СН 2) 4 —CO — ΝΉΟΗ. 5. A composition according to any one of claims 1 to 3, wherein the active ingredient is 2-methylpropane-2-carbonylhydroxamic acid of the formula: СНз AND СНз — C — CO — ΝΗΟΗ. AND СНз Severography, η. ρ. »Plant 7, Most