IL42831A - Process and compositions containing certain oxime derivatives and novel glyoximes for the facilitation of the abscission and ripening of fruit - Google Patents

Description

42831/2 The present invention relates to a process for the promotion and facilitation of fruit abscission, preferably of citrus fruits, and for the acceleration and uniform ripening of fruits of the family solanaceae, such as tomatoes and peppers, both before and after harvesting of these fruits.

An improvement of fruit abscission, i.e. an appreciabl reduction of the picking force to be applied in manual and mechanical harvesting, brings with it great advantages and renders possible appreciable simplifications in the harvesting of large-scale crops; fruit-bearing trees and shrubs are saved from damage due to the tearing away of branches and leaves,* and there is a considerable economy of labour. Furthermore, an accelerated ripening of a part of some fruits, such as of tomatoes and peppers, both at the plant stage and after harvesting, is often greatly desired, so that in large-scale crops (tomatoes) not all the fruit ripens simultaneously to produce a temporary glut.

Various abscission agents and ripening accelerators have already been suggested, but these are frequently unsatisfactory on account of undesirable side-effects.

An example of these is cycloheximide , which, in spite of an excellent abscission action in the case of citrus fruits, has a great disadvantage in that it severely damage blossom and unripe fruit on the tree, has a pronounced defoliating action, and gives rise to considerable scarring on ripe fruit.

A further ripening accelerator and abscission agent to have received mention is 0-chloroethyl-phosphonic acid ("ETHREL", "ETEPHON"), which however, owing to too great a defoliating action, does not always satisfy requirements made of it .

U.S. Patent Specification No. 3,515,536 discloses the use of phenylglyoxine as a plant regulating agent. However, tests carried out have shown that phenylgloxine is clearly inferior when applied as an abcission agent and also does not accelerate ripening as well as a composition according to invention comprising glyoxine as the active ingredient.

The surprising discovery has now been made that certain oximes, oxime derivatives and their salts do not have the disadvantages of the abscission agents hitherto known, and are extremely suitable as agents for the romotion of fruit abscission and ripening.

The process according to the invention comprises the treatment of the fruit-bearing plants or of the fruits themselves with an effective amount of a compound of the general formula I or with a salt of such a compound. is hydrogen, halogen, especially chlorine, an alkyl . 27. VII.73 radical having 1 to 17 carbon atoms optionally substituted for compounds . wherein the with alkanoyl, nitro, halogen, hydroxy, dialkylamino or total number of carbon atoms alkylthio; alkenyl, phenyl-alkyl optionally substituted in R + R is 20 or more. with hydroxy, phenyl or halophenyl or a '-furyl; R~ is hydrogen, to alkyl , cycloalkyl, endoalkylen- cycloalkyl, phenyl optionally substituted with one to three halogen, nitro or alkoxy groups; a heterocyclic radical pyridyl and furyl, or a group ' (CH2)n-C I I N-OR, wherein R has the same meaning as R^, n is an integer from 0 to 3 R^ and taken together form a C^-C^ ring, and R^ and each independently represent hydrogen and substituted or unsubstituted radicals from the group consisting of C^-C-^ alk l, C^-C^ alkenyl, alkylcarbonyl, phenylcarbonyl, N-alkylcarbamoyl, l-alkylthiocarbamoyl N,N-dialkylcarbamoyl,/phenylcarbamoyl, phenylalkyl, alkoxycarbonyl, phenoxycarbonyl, phenylalkoxycarbonyl, alkylthiocarbonyl, phenyl hiocarbonyl, a- furyl and tetrahydropyranyl . dioximes, their O-substituted derivatives and salts.

Substituents on the oxygen atom (R^ and R^) are, as can be seen above, preferably such radicals which are readily split off hydrolytically, aminolytically or metabolically in the plant or in the application agent (spray emulsion) with the formation of the free oxime group (R^=R^=H) .

Particularly suitable radicals for R^ and R^ are those used in synthetic chemistry as protective-groups of alcohols (acyl radicals, etc.) .

The compounds of formula I can be present as cis- and trans-forms .

Preferred compounds for the described field of application are the dioxime derivatives of formula II wherein R^ and R'^ each independently represent hydrogen, chlorine or methyl groups, m denotes the number 0, 1 or 2, and R^ and R^ represent hydrogen or unsubstituted or substituted alkylcarbonyl, phenylcarbonyl, alkylcarbamoyl, dialkyl- carbamoyl, alkoxycarbonyl, phenoxycarbonyl , alkylthio- carbonyl, phenylthiocarbonyl or tetrahydropyranyl radicals, and the salts thereof.

Salts of these dioximes are also suitable, both the salts of strong acids and, if and/pr is hydrogen, the salts of bases, such as the alkali metal salts and alkaline-earth metal salts, as well as the salts of other bivalent and trivalent metals, such as Fe, Cu, Zn, Mn, Co and Al, and also the salts of strong amines.

Particularly preferred aire glyoxime and derivatives of the glyoxime of formula III wherein and each independently represent hydrogen, alkylcarbonyl, alkylcarbamoyl and alkoxycarbonyl, as well as salts of glyoxime.

To effect promotion of fruit abscission, particularly of citrus fruits, the fruit-bearing trees are treated 3 days to 4 weeks before the harvest with agents containing active substances of the above mentioned formulae or salts thereof. For acceleration of ripening, e.g of tomatoes, the fruit itself is treated, either before or after harvesting.

The active substances used according to the invention are in some cases known. New active substances not hitherto described in the literature are, for example, glyoxime derivatives of the more restricted formula IV R wherein R1^ represents hydrogen, C-^ to C-^ alkyl, alkenyl, carbonyl, alkylthiocarbo'nyl or tetrahydripyranyl , and R1^ represents alkyl, alkenyl, phenylalkyl, alkylcarbonyl, phenylcarbonyl, alkylcarbamoyl , N,N-dialkylcarbamoyl, phenylcarbamoyl, alkoxycarbonyl, phenyloxycarbonyl, alkylthiocarbonyl or tetrahydropyranyl .

These compounds are produced in a known manner by a process in which glyoxime or a salt thereof is treated in a solvent such as acetonitrile, acetone, ether, etc., and optionally in the presence of an acid-binding agent, e.g. triethylamine, with an agent introducing the radical R'^ or Suitable agents are, for example, acetyl chloride, phenylisocyanate, dimethylcarbamoyl chloride, methylbromide, chloroforraic acid ester, chlorothioformic acid ester, benzylbromide, alkyl-isocyanates, alkylisothiocyanates , etc..

The following examples describe the preparation of some new oxime derivatives of formula I or IV.

Further oxime derivatives which can be used as active substance for the process according to the invention are listed in the following tables . The temperatures are expressed in degrees Centigrade. phenylalkyl, N-alkylcarbamoyl, Ν,Ν-dialkylcarbamoyl, N-phenylcarbamoyl, alkoxycarbanoyl, phenoxycarbonyl, alkylthiocarbonyl or tetrahydropyranyl, and R'^ represents alkyl, alkenyl, phenylalkyl, alkylcarbonyl phenylcarbonyl, alkylcarbamoyl, N,N-dialkylcarbamoyl, phenylcarbamoyl, alkoxycarbonyl, phenyloxycarbonyl, alkylthiocarbonyl or tetrahydropyranyl.

These compounds are produced in a known manner by a process in which glyoxime or a salt thereof is treated in a solvent such as acetonitrile, acetone, ether, etc., and optionally in the presence of an acid-binding agent, e.g. triethylamine, with an agent introducing the radical R'^ or ^' · Suitable agents are, for example, acetyl chloride, phenylisocyanate, dimethylcarbamoyl chloride, methylbromide, chloroformic acid ester, chlorothioformic acid ester, benzylbromide, alkyl-isocyanates, alkylisothiocyanates , etc..

The following examples describe the preparation of some new oxime derivatives of formula I or IV.

Further oxime derivatives which can be used as active substance for the process according to the invention are listed in the following tables . The temperatures are expressed in degrees Centigrade.

Example 1 ; Glyoxime - 0 - monoacetate. 1 Part of acetyl chloride is added dropwise at 0° to a solution of 1 part of glyoxime and 2 parts of triethylamine in 5 parts of acetonitrile. After being stirred overnight at room temperature, the reaction mixture is concentrated by evaporation to dryness, taken up in water and extracted with ethyl acetate.

The organic phase is dried with magnesium sulphate and concentrated, whereby the product crystallises out as fine, white needles (mp. 124-6°) .

Example 2a: Glyoxime-0,01 -bis-phenylcarbamate . 0.1 Mole of finely powdered glyoxime is suspended in 100 ml of acetonitrile. After the addition of 0.2 mole of phenylisocyanate, stirring is maintained for ca. 15 hours at 20°. The fine, pasty precipitate is filtered off and dried in Vacuo; yield: 95%, mp. 180° (decomposition) .

Example 2b: Glyoxime-0,0' -bis-dimethylcarbamate . 2 Parts of dimethylcarbamoyl chloride are added dropwise at 30-35° to a solution of 1 part of glyoxime and 2 parts of triethylamine in 5 parts of acetonitrile. The formed triethylamine-HCl is filtered off and the filtrate concentrated by evaporation. The residue is taken up in ethyl acetate and the solvent evaporated off.

The light-coloured, crystalline product decomposes on being dried in vacuo at 60°; mp. 134° (decomposition).

Example 3 ; Glyoxime-O-bis-methyl ether.

An excess of methylbromide is introduced into a solution of glyoxime-Na-salt at 0° . After a stirring overnight, the precipitated Na Br is filtered off. From the filtrate there are obtained the desired product, mp. 225°, and a secondary product, mp. 204°.

Example 4: Glyoxime-0,0 ' -bis-ethylthiocarbonate . 2 Parts of chlorothioformic acid-S-ethyl ester are added dropwise at 0° to a solution of 1 part of glyoxime and 2 parts of triethylamine in 5 parts of acetonitrile. A gas (CO2) is evolved during the reaction. The reaction mixture is filtered off from triethylamine hydrochloride and the filtrate concentrated in vacuo. The oily decomposable residue has a smell of mercaptan.

Example 5 : Glyoxirae-0,0 ' -bis-benzyl ether. 22 g of glyoxime is dissolved in 200 ml of 2.5N NaOH at room temperature and 1 litre of acetone added to the solution, whereby the glyoxime-di-Na-salt precipitates. This is dissolved in 10 parts of methanol and 2 parts of benzylbromide are added, whereon a slight exothermic reaction occurs. After several hours' stirring, dilution is performed with methylene chloride, the NaBr removed by filtration and, by concentration of the filtrate by evaporation, a white product, mp. 72°, obtained (yield: ca. 65%) .

Example 6: 0, 0-bis-tetrahydro- 2- pyranylglyoxime .

An amount of 13,2 g of glyoxime is suspended in 50.4 g of 3,4-dihydro-2H-pyran. After dilution with 50 ml of absolute tetrahydrof ran, 50 mg of dry HCl-gas is introduced. The mixture is heated at 45° until a solution is formed. This is stirred, without further heating, for 6 hours, and is then poured into 500 ml of saturated soda so-lution. After extraction of the soda solution three times with ether, and drying and concentration of the organic phases by evaporation, a yellow-brown oil is obtained, which is dried in vacuo at 0.1 mm and 20°; yield: 33.3 g = 86.5%, n^ :J 1.5048·"" Example 7 : 0, 01 -bis-isobutyrylglyoxime . 2 Parts of isobutyroyl chloride are added dropwise at 10° to a solution of 1 part of glyoxime and 2 parts of triethylamine in 5 parts of acetonitrile . Filtration is performed after 2 hours' stirring at 20°; the filtrate is concentrated by evaporation, taken up in methylene chloride, and washed with water. The product, mp. 92°, is obtained from the dried organic phase after concentration by evaporation and recrystallisation from ethyl acetate (80% yield) .

Example 8 : Glyoxime-O-mono-N-methylcarbamate .

An amount of 0.4 mole of methylisocyanate is slowly added dropwise at 30° to a solution of 35 g of glyoxime in 1 litre of abs . ether. After being stirred overnight 20°, the reaction mixture is concentrated cold by evaporation to dryness. The residue is taken up in acetonitrile, and insoluble substance removed by filtration (bis-methylcarbamate) ; concentration by evaporation is then repeated. The dark residue (50 g) decomposes spontaneously on drying in vacuo at 40°;>.mp. 40° (slow heating up) .

Example 9: O-Acetyl-01 -N-methyl-carbamoylglyoxime . 1 Part of ethylisocyanate is added to a solution of 1 part of mono-O-acetylglyoxime (Example 1) in 5 parts of acetonitrile, and stirring carried out for 4 hours at 20° . The precipitated product is filtered off mp. 138°; yield 90%.

Example 10: Pyridyl-l-acetaldoxime chloride. ' 18.7 g of chloroacetaldoxime is dissolved in 200 ml of sulpholane and 50 ml of ether, and 19.8 g of pyridine added to the solution. The reaction mixture is stirred overnight at 20°, and the formed suspension filtered. The residue is dried in vacuo at 12 mm Hg and 20° for 16 hours; yield: 33.2 g = 97%; mp. 100-110°.

Example 11: Glyoxime-0,01 -bis-methylcarbonate . 2 Parts of chloroformic acid methyl ester are added dropwise at 0° to a solution of 1 part of glyoxime and 2 parts of triethylamine in 5 parts of acetonitrile .

After completion of the reaction, the precipitated product is filtered off and the residue stirred with water. A white product, mp. 225° (decomposition), is obtained after filtration and drying .

Example 12: Glyoxime-O, 01 -bis-N-methylthiocarbamate . 2 Parts of methylisothiocyanate are added to 1 part of glyoxime in 10 parts of acetonitrile. After some time, a spontaneous heating to 40° occurs, whereby the reaction mixture becomes reddish. After a stirring time of several hours, the solvent is evaporated off: a red-brown oil 20 is obtained (n^ : 1.595).

Example 13 : Preparation of zinc-bis- (glyoxime) . 2.3 g (0.1 mole) of Na is dissolved in 50 ml of methanol (abs .) , and the solution, after completion of the reaction, heated to boiling. With continuous stirring and refluxing, an addition is slowly made dropwise of 6.8 g (0.05 mole) of ZnCl2 in 100 ml of methanol. The solution is cooled and the precipitated sodium chloride filtered in a separating funnel by the solution being pressed with ^ through a glass suction filter. Washing is then performed twice with 20 ml of methanol. A solution of 8.8 g (0.1 mole) of glyoxime in 100 ml of methanol is placed into a flask and, with gentle heating, the solution of Zn (OCH^) added dropwise. The precipitate is filtered off and dried: 2.9 g, Zn content 36.8%, mp.> 250°. After standing for 4 hours, the mother liquor is concentrated to ca. 80 ml. Trituration with a spatula is performed and a nicely crystallised substance commences to precipitate. It is filtered, washed and driedj yield: 6.0 g; Zn content: 28.3%, mp. > 300° .

Example 14 An amount of 2.4 g of magnesium powder is suspended in 50 ml of absolute methanol, and the suspension stirred until no further hydrogen is liberated. An addition is then made dropwise of 8.8 g of glyoxime in 100 ml of methanol. After 30 minutes, the methanol is evaporated off in vacuo. Residue 11.0 g of magnesium glyoximate, mp. > 220° .

The preparation of the calcium salt and aluminium salt, respectively, is effected by the same procedure, with calcium hydride or aluminium being used instead of magnesium.

The active substances of formula I are not phytotoxic in the usual application concentrations, and they have low toxicity towards warm-blooded animals. They moreover produce no morphological changes of the plants or cause damage to them.

They promote, in particular, the ripening of the fruit and the development of abscission layers, particularly between stalks and petioles. Consequently, fruits of all kinds, e.g. stone fruit (cherries), berries, grape vines, pomaceous fruit (apples) or oil fruits (olives), and particularly citrus fruits such as oranges, lemons, grapefruit, etc., can be separated from the fruit stems, manually or mechanically, without any great amount of force being applied. Damage to foliage and branches which normally occurs when fruit is removed by the shaking of trees and shrubs, or by the plucking of the fruit from the branches, is largely avoided, and the production capacity of the trees thus increased.

The extent and nature of the action are governed by the most diverse factors, depending on the type of plant, particularly, however, on the applied concentration and on the time of application with regard to the stage of development of the plant and the fruit. Thus, for example, plants of which the fruit is to be sold, or in some other way utilised, are treated immediately after blossoming or at an appropriate length of time before the gathering of the fruit . The active substances are applied preferably in the form of liquid preparations, these being applied to parts of plants above the soil, to the surface of the soil or into the soil. Application to parts of, plants above the soil is preferred, for which purpose solutions or aqueous dispersions are most suitable.

The active substances of formula I are used together with suitable carriers, solvents and/or other additives. Suitable carriers and additives can be solid or liquid, and correspond to the substances normally used in formulation practice, such as, e.g. natural or regenerated mineral substances, solvents, dispersing agents, wetting agents, adhesives and thickening or bonding agents.

The applied amounts are largely governed by the purpose and nature of the application (treatment of the soil or of parts of plants) . The usual amounts applied in the case of soil treatment and for crops are between 1 and 10 kg of active substance per hectar of land under cultivation.

The agents for promoting abscission and accelerating ripening which contain active substances of formula I can be formulated as aqueous or non-aqueous solutions and dispersions, emulsifiable concentrates, wetting powders of dusts, optionally with additional amounts of anti-o idants , such as hydroquinone , Such formulations can contain 2 to 95 per cent by weight t preferably 80 to 90 per cent by weight, of active substance, and can be prepared by the techniques normally applied in agricultural chemistry.

Preferred preparations are aqueous ones having a content of 0.1 to 1% of a nonionic wetting agent. 0.1 About -θ-rfS- to 16 kg, preferably 1 to 4 kg, of active substance is employed per hectare of area under cultivation.

The time of application to promote fruit abscission is shortly before harvesting, i.e. 3 days to 4 weeks before harvesting; and to accelerate ripening, shortly before or after the harvesting of the fruit.

Where the application is for acceleration of ripening, a uniform ripening occurs, without any disadvantageous effect on the quality of the fruit .

Preferred ripening accelerators are glyoxime, dimethy1-glyoxime, dichloroglyoxime and their derivatives. The suggested active substances are particularly suitable for the ripening of tomatoes, but also of peppers and egg-plants.

Both the treatment before and after harvesting is carried out by spraying or dusting; after harvesting also by immersion in a liquid active-substance preparation.

Pretreatment prior to harvesting is preferred: 7 to 10 days before the intended time of harvesting.

Applied amounts of 0.5 to 1 kg of active substance per hectare of area under cultivation suffice in the case of fruit ripening. The absence of phytotoxicity and the good water-solubility of most of the active substances are the great advantages of the ripening accelerators suggested according to the invention.

The determination of the abscission action on citrus plants was made by the following methods: A.) On freshly sprouted branches of Citrus sinensis var . Volkameriana, the leaf surface was cut off from 8 leaves, leaving only the leaf-stalks on the branch.

Two such branches in each case were then sprayed with active-substance solutions of 4000 and 2000 ppm active-substance content, respectively. The test was evaluated . after 7 days on the basis of the number of shed leafstalks. In all the control tests, no leaf-stalk was shed.

B.) Parts of branches of orange trees (variety Hamlin or Pineapple or Valencia) carrying at least 20 oranges were sprayed with active-substance solutions shortly before harvesting. The evaluation of the test results was made after 7 days, with two different systems being employed: a) Measurement of the plucking force and determination of the reduction thereof effected, with respect to the untreated control specimens . b) Number of shed oranges (without shaking) in per cent, compared with the untreated control specimens (0%) .

All active substances tested produced, with no or negligible shedding of leaves, an intense development of abscission layers on the fruit-stalks, an appreciable reduction of plucking force, and some of them even good values with regard to the shedding of fruit .

Especially good results have so far been obtained with compounds Nos . 8, 17, -31-¾ 42, 67, 97 and 98.

In the case of Hamlim oranges with 4000 ppm concentration of active substance 0- (2-chloroethoxycarbonyl) -butane-oxime, the plucking forces required after 7 days were less than a quarter of those required for untreated oranges, these being 9 to 11 kg per orange. Similarly good reductions in plucking force were obtained with dichloroglyoxime, whilst the plucking forces on application of glyoxime and Ν,Ν-diethylhydroxylamine decreased already with 500 ppm to practically zero, i.e. shedding of fruit occurred.

Tomato ripening test Immersion test with plucked green greenhouse tomatoes of the variety "Hybrid" .

The active substances were prepared, in a concentration of 2000 and 1000 ppm, as an aqueous liquor with an addition of wetting agent. Each test was carried out with 2 1 of this liquor and 20 unripe picked tomatoes, the procedure being that the tomatoes were immersed for 1 minute in the liquor, and then stored in an air-conditioned room with 70% rel. humidity and at 20°C, with a daily 10-hours1 exposure to light (20,000 Lux), until (ca. 14 days) 90% of the tomatoes were fully ripe. The attained degree of ripening was assessed visually each day (0%, = 9 = green; 100% = 1 = fully ripe) .

With the various active substances, it was possible to observe a clearly accelerated ripening compared with that in the case of the untreated control tomatoes .

Thus, of the 20 unripe tomatoes treated with 1000 ppm of glyoxime, seven had attained full ripeness after 7 day and five 70-90% ripeness: 12 tomatoes were fully ripe after 9 days. In the control test with untreated tomatoes only one tomato was fully ripe after 7 days : after 9 days the number fully ripe was 6.

The phenylglyoxime serving as a comparative substance which is not included in the present application, exhibit a clearly inferior action in that after after 7 days only 4 tomatoes had attained full ripeness and 3 were 70-90% ripe.

Claims (10)

1.) Process for the promotion and facilitation of fruit abscission, and for the acceleration and uniform ripening of mature green fruits of the Solanaceae family, which process comprises the treatment of the fruit-bearing plants or of the fruit itself with an effective amount of a compound of the general formula I N-OR, or with a salt of such a compound, the symbols in this formula having the following meanings , ..·.: . · R 1 is hydrogen, halogen, especially chlorine, an alkyl 27. VII.73 radical having 1 to 17 carbon atoms optionally substitute for compounds wherein the with alkanoyl, nitro, halogen, hydroxy, dialkylamino or total number of carbon atoms alkylthio; alkenyl, phenyl-alkyl optionally substituted in R + R is 20 or more. with hydroxy, phenyl or halophenyl or a'-furyl; R is hydrogen, to alkyl , cycloalkyl, endoalkylen- 2 cycloalkyl, phenyl optionally substituted with one to three halogen, nitro or alkoxy groups; a heterocyclic radical pyridyl and furyl, or a group N-OR 4 wherein R has the same meaning as R^, n is an integer from 0 to R^ and R£ taken together form a ^^'^12 r^n§' anc R^ and R^ each independently represent hydrogen and substituted or unsubstituted radicals from the group consisting of C-^-C^ alkyl, C-^-C^ alkenyl, alkylcarbonyl, phenylcarbonyl, N-alky1carbamoyl , N-alkylthiocarbamoyl, N,N-dialkylcarbamoyl,/ phenylcarbamoyl, phenylalkyl, alkoxycarbonyl, phenoxycarbonyl, phenylalkoxycarbonyl, alkylthiocarbonyl, phenylthiocarbonyl, a-fury1 and tetrahydropyranyl .

2.) Process according to Claim 1, wherein the active substance employed is a compound of formula II wherein R^ and R'^ each independently represent hydrogen, chlorine or methyl, in denotes the number 0, 1 or 2, and R^ and R^ each independently represent hydrogen or substituted or unsubstituted alkylcarbonyl, phenylcarbonyl, alky1carbamoyl, dialkylcarbamoyl, alkoxycarbonyl, phenoxycarbonyl, alkylthiocarbonyl, phenylthiocarbonyl or 2-tetrahydropyranyl radicals.

3. ) Process according to Claim 2 wherein amine salts, alkali metal and earth-alkaline metal salts, as well as the salts of Fe, Cu, Zn, Mn, Co or Al of a compound of formula II in which and/or denote (s) hydrogen, are employed.

4. ) Process according to Claim 1 comprising the use of a compound of formula III CH CH (HI) wherein R^ and R^ each independently represent hydrogen, alkylcarbonyl, alkylcarbamoyl or alkoxycarbonyl .

5. ) Process according to Claim 4 wherein glyoxime or a salt thereof is employed.

6. ) Process according to Claim 1 or 2 for the promotion and facilitation of fruit abscission, particularly of citrus fruits, in which process the fruit-bearing plants are treated, 3 days to 4 weeks before harvesting of the fruit, with an effective amount of a compound of formula I or II, or of a salt of such a compound.

7. ) Process according to Claim 4 for the acceleration of ripening of Solanacious fruit, especially tomatoes and peppers, in which process these fruits are treated in the unripe condition, before or after harvesting, with an effective amount of a compound of formula III, or of a salt thereof. - 29 -

8.) Process according to Claim 6 comprising the treatmen of citrus trees with glyoxime.

9.) Agent for the promotion and facilitation of fruit, abscission, and for the acceleration and uniform ripening of mature green fruits of the Solanaceae family which contains as active component, a compound of the general formula I of Claim 1. v.

10.) New glyoxime derivatives of formula IV CH CH (IV) R3'0-N N-0-R'4 wherein R1^ represents hydrogen, C^ to C^ alkyl, alkenyl, phenyl- alkyl, N-alkylcarbamoyl, N,N-dialkylcarbamoyl/N-alkylthi carbamoy N-phenylcarbamoyl, alkoxycarbonyl, phenoxycarbonyl, alkylthiocarbonyl or tetrahydropyranyl, and R1^ represents alkyl, alkenyl, phenylalkyl, alkylcarbonyl, phenylcarbonyl, alkylcarbamoyl, Ν,Ν-dialkylcarbamoyl, phenylcarbamoyl, alkoxycarbonyl, phenoxycarbonyl, alkylthiocarbonyl or tetrahydropyranyl, as well as salts of these derivatives .