DD286285A5 - MEANS FOR CHEMOTHERAPY OF VEGETABLE VIRUSES - Google Patents

Abstract

The invention relates to agents for the chemotherapy of plant viroses. The object of the invention is to improve the chemotherapeutic measures against plant viruses. The task is seen in the discovery of new chemical agents that inhibit the replication of plant viruses due to their chemical constitution in conjunction with adjuvants and traeger substances and thus u. a. expanded the possibility of reproductive rotation and thereby to prevent the emergence of refractory virus vesicles. The object is achieved by the use of preparations which contain substituted methallyl thioureas of the general formula C-CH 2 -NH-CH 2 CH 3S {antiphytoviral compounds; antiphytoviral chemotherapy; Methallylthioharnstoffe; synergies; * Potato viruses}

Description

CH ₃ S

¹ "12

CH ₂ = O - GH ₂ - NH - O - NR ¹ IT

be used.

In addition to one or more of the compounds of the general formula according to the invention, the agents may contain diluents and / or solvents, moreover, where appropriate, adhesives and / or further formulation auxiliaries. Used together with 2,4-dioxohexahydro-1,3,5-triazine (= azadihydroiiracil), their antiphytoviral activity often increases synergistically. The agents of the invention show a pronounced antiphytoviral activity, in particular against economically important potato viruses, e.g. against potato X virus as well as against the potato viruses Y, A, R and N as well as the leaf roll virus of the potato, which generally respond to antiphytoviral preparations similar to potato X virus. It is also possible to combat further viruses that are harmful to tomato, tobacco and other crops.

In order to achieve sufficient protection for the practice, application rates of 0.25 to 8 kg / ha are generally sufficient. The formulation and application of the compositions according to the invention can be carried out by the known and customary methods. Thus, the active ingredients can be mixed with inert diluents and suitable formulation agents and processed into wettable powders, pastes, emulsion concentrates, granules, etc. It has proved to be advantageous if the active substance content makes up 60 to 90%, in granulates 5 to 60% of the agent. The agents can be dissolved before use with water or dispersed to spray and applied with conventional spray, spray and fog devices.

Execution oolsplele

To characterize the enhanced antiphytoviral activity of the compounds according to the invention, whole plant tests on solanaceae were used in particular. In particular, the effect of the compounds of the invention on the systemic multiplication of potato virus X (PVK = potato virus X) in the top inoculated leaf of Nicotiana tabacum 'Samsun' and in a secondary infected leaf from the top inoculated leaf was determined by at least 2 leaves was separated, proved. The viruses were inoculated when performing these tests using an abrasive (carborundum powder, grain size 600). The erfindungsgomäßen compounds were in each case 2 days before and 2 and 7 days after inoculation using suitable solvents or suspending agents, usually ethanol or cyclohexanone, and with the addition of 0.2% Fekama adhesive in the concentrations indicated in the tables , usually 5mmol / l, applied to the dripping wet on the plants. This corresponds, under practical conditions, to the application of 600 l spraying solution or broth per hectare of field surface. The concentrations of the solvents shown in detail in the series and the preparations were determined in preliminary experiments. As a control, a number of plants were inoculated with the same virus and treated with dom same solvent-water mixture with the addition of 0.2% Fekama adhesive, but without the active compounds of the invention.

The virus concentration was planted serologically in the precipitation drop test using the dilution end point determination (geometric dilution in each case at a ratio of 1: 1 with physiological saline until virus is no longer serologically detectable) in the intervals indicated in the example series from the inoculation in leaves Separately determined leaf-wise (G. Schuster, Archiv Phytopath., and Pflanzenschutz 7, 1971, 171-187 and 13, 1977, 2131-241). Each experimental member comprised 8 to 10 individual plants. The virus concentration found in the leaves of the individual plants was expressed in value numerals. In this case, value 0 means that no virus was detectable even in a 1: 1 diluted (starting) press juice. The value 1 shows that after a further further dilution in a ratio of 1: 1 no more virus could be detected, the value 2, that after two dilutions no virus precipitate occurred, etc. For comparison of the results obtained in the Versuchsglicdern with those of the control was the individual numerical values, which represent logarithms (exponents) to base 2 according to the described experimental arrangement, formed the corresponding antilogarithms. The latter were averaged. The mean values of the virus concentrations of the plants subjected to antiphytoviral chemotherapy I = Mmth) were subtracted from the corresponding mean values of the control plants (Mk). The difference obtained is in the example series according to the formula

_{H m m}

Hk

represented as a relative word of control. These values indicate by how many% the virus concentration in the leaves of the antiphytoviral methallyl thioureas according to the invention was reduced (= inhibited) compared to the virus concentration in control plants. The value 60 means reduction by 60%, d. H. on 40% of the controls, the value 100 complete, the value 0 at all no inhibition. The significance of the differences found was checked in the t-test, possibly followed by suitable transfomation, e.g. appropriate Radiation, normal distribution of the measurements had been brought about. The test result was indicated next to the inhibition% in symbols. These say:

": p> 5%

**: 1% Sp> 0.1% "*: 0.1% 6p

ρ = exceedance probability

The results of the experiments carried out in the manner described are summarized below in two examples.

In Belsplelirelh * 1, it is shown that the N-cyclohexyl-N, N'-dimethylellyl thiourea of the present invention (Serial No. 2) greatly inhibits potato X virus in both the inoculated and secondary infected leaves. A similarly good inhibitory effect is achieved by application of N-MethallylN'-phenyl-thiourea (no. 3). N-Methallyl-N '- (a-naphthyl) thiourea (Serial No. 6) exerts its inhibitory effect especially in the inoculated leaf, which will be of practical importance in combination with other methallyl thioureas.

Beltlet series 2 shows that the effect of N-cyclohoxyl-N, N'-dimethylallyl-thiourea (No. 2) and N- (p-bromophenyl) -N'-methyl-thiourea (No. 5) Addition of small amounts of DHT is synergistically increased so much that no virus can be detected in the precipitation drop test. The effect of other methallylthioureas according to the invention can also be considerably increased by adding small amounts of DHT. Extremely strong synergistic effects arise, for example, when N-methallyl-N'-methyl-N'-phenyl-thiourea (No. 4) or N'-methallyl-N '- (α-naphthyl) -thiourea (Lfd No. 6) can be administered together with small amounts of DHT.

Belpieltrelhe 1 Inhibition (percentage reduction in concentration) of potato X virus in inoculated (inoc. Bl.) And secondary

infected (sec.in., bl.) leaves of Nicotiana tabacum 'Samsun' by the methallyl thioureas of the invention.

Virus content determination serologically in the precipitation drop test at Endpunktbestimmung. The relative values give, um

how much% treatment with the compounds of the invention occurred 2 days before and 2 and 7 days after inoculation with PVX, decreased the viral concentration of the untreated, infected controls. Examination of the iminoculated leaf (= 3rd leaf over the cotyledons) for 5 to 7 days, usually 5 days, in the secondary infected leaf (= 5th leaf or leaf above the cotyledons) 12 to 15 days (usually 13 days) the inoculation. TH - thiourea,

Lsm = solvent; Eth. · »Ethanol, final conc. 5% in H ₂ O; Cy = cyclohexanone, final conc. 2% in H ₂ O. In the examples

each indicated the concentration with the optimal effect.

Ser. connection Conc. Solvent. Reduction d .Viruskonzentration No. iMM) rel., control = 0% 8ek.inf.Bi. 1 N, N'-Bismethallyl-TH 5 Eth 48 49 * 2 N-cyclohexyl-N, N'-dimethylallyl-TH 5 Eth 68 ** 67 ** 3 N-methallyl-N'-phenyl-TH 5 Eth 67 ** ⁺ 50 * 4 N-methallyl-N'-methyl-N'-phenyl-TH 10 Eth. 24 29 5 N- (p-bromophenyl) -N'-methallyl-TH 5 Eth. 43 50 * 6 N-methallyl-N '- (a-naphthyl) -TH 5 Cy 73 - ** 29 7 N-allyl-N'-methallyl-TH 5 Eth 26 54 * 8th N, N'-bisallyl TH 5 Eth 32 68 *

Beisplelsreihe2 Increased inhibition (percentage reduction in concentration) of potato X virus in inoculated (i.) Or secondary

infected (s.) Leaves of Nicotiana tabacum 'Samsun' by combination (combination) of the invention

Methallylthioharn. offe with 2,4-dioxohex ihydro-1,3,5-triazine (DTH, 0.005%). Lsm = solvent control = reference = 0% He.nmung. Further explanations see example series 1.

Ser. No.

(AusBeispr.1)

Connection and Conc. (MM)

Reduction d. virus concentration DHT / Solvent Kombi / Solvent rel. for control 92 *** 100 *** TH / Solvent. 84 "** 88 *** s. 62 * 7 56 ** s. 24 50 * 100 *** i. 24 38 67 '* s. 50 * s. 13

N-Cyclohexyl-N, N'-dimethylallyl-TH (10) N-Methallyl-N'-phenyl-TH (5) N-Methallyl-N'-methyl-N'-phenyl-TH (IO) N- (p -Bromphenyl) -N'-methylallyl-TH {5) N-Methallyl-N '- (a-naphthyl) -TH (5)

Claims (3)

¹ "12 , CH ₂ = C - CH ₂ --NH - C - NR ¹ IT contain. 1. Composition for the chemotherapy of plant virions, characterized in that they are substituted in addition to customary auxiliaries and excipients as active ingredient methallylthioureas of the general formula CH, S 2. Composition according to claim 1, characterized in that the preparations used in addition to the active compounds according to the invention contain surfactants, adhesives and other formulation auxiliaries and optionally excipients for the formation of granules. 3. Composition according to Claims 1 and 2, characterized in that the antiphytoviral action of the active compounds according to the invention is synergistically increased by combinations with hydrogenated triazines. Field of application of the invention The face of the big yield losses that. by viruses in many agricultural and horticultural crops of the family Solanaceae, z. As in potato, tomato odor tobacco, but also in other crops, such as food and fodder legumes, beets and numerous vegetables and ornamental plants, caused, it is urgently necessary, the so-called classic, mostly indirect measures dor virus fighting, including u.a. Resistance breeding, which includes the control of virus carriers and the negative selection of virus-infected plants, must be supplemented with methods that enable chemicals to reduce virus infestation to an economically justifiable level and thereby achieve higher and more stable yields. The invention relates to a method for controlling plant viroses by way of chemotherapy. Characteristic of the known state of the art In recent years, a larger number of preparations have been found or inhibited, which inhibit the multiplication of plant viruses. These include analogs of purine and pyrimidine bases or of corresponding nucleosides and nucleotides, antibiotics, polyanions, substituted and hydrogenated triazines, ureas and thioureas, guanidines, compounds with azine structure, thiadiazoles and oxazoles, α-benzylthiocarbonylimino compounds, vinylaldehyde / thio / semicarboxylic zone , Alkyllysophospholipide, lipid extracts and fractions isolated therefrom, which are obtained in the fermentation of hydrocarbons and Hefebiomas3en, obtained by partial hydrolysis of corresponding Phosphatidfraktionen antiphytoviral compounds and rhamnolipids. An overview of this is u. a. in the patents DD-PS 157662 from 01.12.82 and DD-PS 244 Al from 01.4.87 given. Furthermore, certain lignosulfonates (DD-PS 24490? Al of 22.4.87) and metal complexes with substituted thioureas (DD-PS 251486 A1 and DD-PS 251487 A1 of 18.11.87) have become known. The variety of viruses and their z.T. however, very different replication strategies, as well as the high mutation rates that are found, especially in many multicomponent viruses, by recombinant formation and which suggest the emergence of candidate resistant forms, require even greater variety in the available antiphytoviral preparations. Object of the invention The object of the invention is to increase the range of antiphytovirally active compounds, with new agents for the chemotherapy of plant viroses in particular the possibilities for preparation rotation, i. for the alternating application of different preparations, as well as for the preparation combination to be extended, in order to better prevent the killing of preparation-resistant virus isolates. Explanation dft essence of the invention The invention has for its object to find agents that effectively inhibit virus replication due to their chemical structure, can be included in a preparation rotation and thus prevent the emergence of resistance and possibly in combination with hydrogenated triazines, especially with the highly effective preparation antiphytoviral 2, 4-Dioxohexahydro-1,3,5-triazine (DD-PS 115566 v. 12.10.75) lead to a synergistic increase in antiphytoviral activity.
The object is achieved in that means for controlling plant viruses means of the general formula