DD268111A3 - MEANS FOR INDUCING RESISTANCE TO BACTERIAL PATHOGENES IN CULTURAL AND UTILITY PLANTS - Google Patents

Abstract

The invention relates to means for the chemical induction of resistance to bacterial parasites in crops and crops containing as an effective component a stilbene compound, together with suitable tracer compounds and / or surface-active agents; One or more active compounds can be present in the agents according to the invention. - The funds are used to increase the resistance of plants - by activating the plant's own defense mechanisms - which can effectively counteract the development or spread of pests - the spread of bacterial pathogen-related plant diseases in agricultural and agricultural crops. The introduction of a resistance-inducing principle into a plant population (through an economically sensible and ecologically acceptable method) offers possibilities of pest control, which go beyond previously known principles. It has been found that use of the phenomenon of induced resistance as an effective plant protection measure is possible if, for the purpose of induction, derivatives of the chemical structure class of the stilbenes are used as "resistance regulators". The compounds according to the invention are synthetically easily accessible, physiologically acceptable substances which can be used; They meet the high demands that are placed on an active ingredient today, largely. As the requirements for toxicological safety and environmental friendliness.

Description

Description of the invention Title of the invention:

Agent for inducing resistance to bacterial pathogens in crops and crops

application areas <* He Invention:

The invention relates to agents for the chemical induction of resistance in crops and crops.

The funds are used to increase the resilience of crops and crops. The funds are used in the laboratory and greenhouse area and in the field - under practical growing conditions - application for the induction of resistance to various infectious diseases, such as

(a) Bacterial tomato wilt (Corynebacterium michiganenee)

- tomato (Lycopersicon esculentum L.)

(b) leaf and fruit spot disease (Pseudomonas tomato)

- tomato (Lycopersicon esculentum L.)

(c) angular leaf spot disease (Pseudomonas lachrymans) cucumber (Cucumis sativus L.)

(d) Greasy blotch disease (Pseudomonas phaseolicola)

- bean (Phaseolus vulgaris L.)

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Characteristic of the known technical solutions;

Information on the known technical solutions with reference to their deficiencies, which are eliminated by the invention:

1. Direct pest control

With the conventional plant protection and pesticides (PSM - see KEMPTER, G .: OL) NAR, A .: chemistry of organic plant protection and pest control means, VEB German publishing house of the sciences, 2. AufIg., Berlin 1983) and procedures for the direct pest control By no means can all infectious diseases be satisfactorily controlled. The use of pesticides is particularly limited by the appearance of resistance in the pathogen population; The success of resistance breeding is also accompanied by an increasing selection of pathogen races (pathotypes) which have become resistant to pesticides. - The application of PPPs for direct control of pests are increasingly ecological and toxicological, z. T. also counter economic problems.

An increase in PSM production does not guarantee any improvement in crop protection. Recent years have clearly demonstrated the environmental problems that can result from careless and uncontrolled use of pesticides (eg insecticides, herbicides); The development of new pesticides of this kind can not be regarded as a real solution, but the conventional PPPs were still allowed to retain their high economic importance in the long term.

The mentioned disadvantages of the direct control of pest control necessitate research in principle of new methods of plant protection and pest control or to look for further rationalization possibilities.

2. Increase the resistance of the plants

The economically important infectious diseases of crops and crops can not be effectively combated with chemical agents today.

Alternatives provide the methods for increasing the resistance of the plants; These include the breeding of resistant varieties and the induction of disease resistance (resistance activation).

2.1. Breeding resistant varieties

The great successes of resistance breeding are accompanied by an increasing selection of pathogen races (pathotypes); By natural selection - counteracting pathogens, the resistance of new plant forms is broken. Furthermore, in some areas of plant breeding, it is becoming increasingly difficult to combine the demands for high yields and good quality in breeding with high resistance properties at the same time.

2.2. Induction of disease resistance

In principle, the aspect of activating natural defense systems (through an economically viable and ecologically viable process) offers completely new ways of controlling plant diseases. For today's crop protection, this raises the question of whether practicable means and methods for increasing the resilience of crops and crops - without genetic intervention - can be developed. A key problem is the way in which a permanent introduction of a resistance-inducing principle into a plant population succeeds.

J66

So far, resistance inducers-substances capable of activating resistance mechanisms in plants-of microbial origin have been found to be particularly effective, but their chemical nature has scarcely been reported; one used z. For example, culture filtrates of cultures of certain bacteria (Bacillus subtilis, Pseudomonas aeruginosa) which had not been processed as inducer solutions and which had been detected as producers of the rssistenzinduktors (SCHÖNBECK, F., DEHNE, H.-W., BALDER, H .: the effectiveness of induced resistance under practical growing conditions I. Powdery mildew on vines, cucumbers and wheat Z. Plant diseases and plant protection (1982) 89, 177-184). It was found that plant stocks can be protected against infection by the phenomenon of resistance induction even under practical cultivation conditions. Field trials of this kind were mainly by F. SCHÖNBECK u. Al. (University of Hannover / Germany). However, the development that makes such models applicable to plant protection is still in its infancy; see. BtICHT, W .: How did "immunized" plants run? Natural sciences. Rundschau (1984) 37, H. 8, 309 - 312. - The disadvantage of these solutions arises from the requirement for defined active ingredients hzw. standardized substance mixtures; Expensive Reinigungsoporationen could be associated with considerable costs.

In many models, the induction of resistance was achieved by a slight initial infection with the pathogen, by contact of the plant with other pathogens or weakly virulent pathogen races. However, the application of a pathogen to a plant population does not appear to be useful in practice, which, among other things, probably explains the low importance of the method in the past (SEQ.UNA, L .: The Acquisition of Systemic Resistance by prior inoculation., In: supra DALY 3. URITANI: Recognition and specificity in plant host-parasite interactions, Japan Scient. Soc., Press, Tokyo 1979).

In addition to these representations, there are other, but less practical, studies on the phenomenon of induced resistance; numerous cases of induced resistance to fungal, bacterial and viral diseases are documented in the literature. In order to induce resistance, non-pethogenous breeds of pathogens, non-pathogens of the host, pathogens and metabolic products of hosts or of infectious agents were used (for summary, see BEICHT, W .: Investigations on the induction of resistance mechanisms in plants by microbial metabolites, Diss. Univ. Hannover 1981. KUC, 3 .: Multiple mechanisms, reaction rates and induced resistance in plants In: RC STAPLES; GH TOENIESSEN (Eds.): Plant disease control - resistance and susceptibility John Wiley & Sons, New York, Chichester , Brisbane, Toronto 1981, pp. 259-272 WOOD, RKS: Active defense mechanisms in plants, New York: Plenary, 1982, 1 - 381).

In recent years, progress has been made in detecting or isolating and identifying (structural clarification) of plant resistance inducers (see HOFFEREK, H .: New Approaches to Biochemistry and Physiology of Disease Resistance of Plants.) Series "Lectures in the field of AdL" , 1983, H. 1, 35-60); However, such metabolites are present in very low concentrations in the plant, so that in the best case, only conceptions for the synthesis of structural analogues should be relevant to practice (see also CJENNS, A., KUC, 0.: Graft transmission of systemic resistance of .ucumber against Colletotrichum lagenarium Physiol Plant Pai.iol (1979) 69, 753-756).

Drug research in the PSM industry has led to the discovery that a fungicide known per se - the compound

2,2-Dichloro-3, S-dimethylcyclopropanecarboxylic acid (WL 28325) against the pathogen of the Reiandoäune, Pyricularia oryzae, resistance to xMduzlereii is able (LANGCAKE, P., CARTWRIGHT, D. RIDE, 0 P .: The djehlorocyelopropanes and Other fungicides with indirect mode of action In: Systemic Fungicides and Antifungal Compounds, proceedings of a symposium, Reinhardsbrunn, GDR, ed H. LYR; C. POTTER, Akndemie publishing house, Berlin 1981); Additional dichlorocyclopropane derivatives with a corresponding indirect effect were found. It has been shown that antifungal agents can act by influencing the plant metabolism. Other examples of an indirect mode of action of fungicides have been described (WADE, M .: Antifungal agents having an indirect mode of action. In: AP 0. TRINCI; 0. F. RYLEY (Eds.): Mode of action of antifungal agents. Cambridge University Press, Cambridge, London, New York 1,984, pp. 283-298); it is u. a. the means aliette, phenylthiourea, procbanazole. Such "fungicides" (which includes the o.G. substance WL 28325) induce in the plant the synthesis of certain antibodies (phytoalexins). However, the same reaction can also by other so-called stress factors - such as cold, UV radiation, mercury salts, various inorganic or organic substances - are triggered; the effect - known in principle for a long time is nonspecific and highly stressful for the plant in physiological Minsicht. Other disadvantages are: disturbance of the development process of the plant (loss of yield, quality loss), ecological and toxicological problems.

For practical plant protection, the indirect mechanisms of action of fungicides have so far had no particular significance; such funds do not meet the high demands that are rightly made of modern plant protection products.

For the chemical resistance induction, as described in the present patent, are so far no information, information or advice in the literature before.

The present invention overcomes the stated deficiencies of the hitherto known technical solutions; the agents of the invention produce - they are applied - resistance to bacterial pests by activating plant-own defense systems (indirect pest control), they are physiologically harmless in all application variations. Phytotoxic effects have not been detected in any case. Special examinations also showed no toxic effects in humans and animals.

The active compounds of the presented agents are readily accessible by chemical synthesis; The industrial production of the funds is very economical, just as much as in the agricultural and horticultural practice their application (application rate) is extremely economical.

Object of the invention

The object of the invention is the induction of resistance to pathogenic bacteria in crops and useful plants, which is to be effectively countered the development or spread of pests - the spread of bacterial plant diseases in agricultural and horticultural crops.

The use of a resistance-inducing principle in a plant stock offers possibilities of pest control that go beyond previously known principles.

Physiologically acceptable, synthetically produced, chemical resistance activating agents are intended to make it possible to exploit the phenomenon of induced resistance to control bacterial infectious diseases in crops and crops with ecological benefits and high utility in increasing and stabilizing yields without genetic intervention and without the use of toxic pesticides.

Exposition of the invention W esens

The methods used in practical plant protection for direct pest control are, as already stated, in ecological, toxicological, z. T. also in economic terms not always problem-free. The increasing selection of strains which have become resistant to pesticides is also problematic. In addition, these methods can not control all major infectious diseases. Alternatives offer the methods to increase the resistance of the planters .. These methods include above all the breeding of resistant varieties; the use of such varieties is burdened with the problem of resistance to overcome by virulent pathotypes whose selection may be favored under modern cultivation conditions. On the other hand, plants have a natural resistance potential, which is characterized by a high degree of elasticity and can be activated by non-genetic type interventions (induced resistance phenomenon).

, 260 4Ή

The technical problem solved by the invention is of a complex nature and comprehensively defined:

It consists in the control of plant parasitic bacteria - by activation of natural defense mechanisms of plants using agents (inducers), the use of which is economically reasonable and ecologically acceptable.

The use of the funds makes it possible to exploit the phenomenon of induced resistance as an effective phytosanitary measure (indirect control of pathogens).

Compared to the conventional methods for pest control, there are no toxicological and ecological problems when using the means; the economics of production and application of the agents of the invention (compounds of general formula I) is highly favorable compared to, for example, conventional bactericides.

It has now been found that the object of the invention is achieved in an outstanding manner if, for the purpose of induction, ale "resistance regulators" derivatives of the chemical structural class of the stilbenes are used. The agents according to the invention contain as active component at least one stilbene compound of the general formula I:

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^R 1 ^R 3

I ¹

NN . _v s-. NN

SO ₃ X SO ₃ X

(Formula I)

X is Nn ₁ K ₁ NH. or aliphatic amine and R ₁ to R ₄ are different or p & arweise R ₁ + R "and R ₂ + R ₄ are the same or R ₁ to R _{4 are the} same.

R ₁ means

Cl, -OH, -NH ₂

aliphatic primary or secondary amines having preferably one to four carbon atoms, which may furthermore carry oxy or oxyalkyl groups

- cycloaliphatic amines / ^ 2 * ~ ^ 2 * \

- heterocycles such as ^ k

PU PU '

₂ CH ₂

- Where appropriate, substituted aromatic amines or phenols, in particular of the compound strain benzene or naphthalene, their substituents z. B. -Cl, -CH ₃ , -CH ₂ -CH. ,, · - OCH ₃ are.

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J26 & ΑΛΛ

means either R ₁ or a substituted aromatic amine of general formula II

CIV

SO ₃ X

(Formula II)

where X has the abovementioned meaning and Z stands for -H ₁ -Cl or -SO ₃ X.

Furthermore, R "is a compound of general formula III

(Formula III) where X and Z are as defined above

can also be a substituted aromatic amine of the basic structure (formula IV)

B A ^

wy ι \ jSj - ^NH 2

ZX ZX

(Form IV)

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in which also X and Z are those listed above

Meanings have and either in ring A or B in pairs

stand or isolated such that at X in the ring A with above

meaning X in the ring B = H is unc * vice versa; the same applies to Z.

If R ₁ to R _{4 are} different, the substituents correspond to the entire possibilities of R ₁ and R ".

The ready-to-use agents contain one or more biologically active compounds of the above-mentioned type. Type (formula I) together with carriers and surfactants (surfactants in general).

The type and number of components contained in an agent, the selection or combination of the active compounds corresponds to the intended use; In principle, the most diverse combinations of compounds of the general formula I are possible, the spectrum of action can be extended or varied - the combination options are not limited only to the compounds (formula I), the active agents composition of the invention can, for. B. Can be combined with growth regulators, herbicides or fungicides.

The use of such combination preparations z. B. in cereal cultivation could be economically particularly useful. In horticultural crops, on the other hand, agents with specific effects will have greater meanings.

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J6 &

Example 1:

Increase the resistance of tomatoes to bacterial wilt disease (Corynebacterium michiganense)

For bacterial wilting susceptible tomato plants (Lycopersicon sp.) With aqueous solutions of an active compound of the formula

G) -SO, Na

N N

-NH -

CH =

SO ₃ Na

treated before the infection.

(Formula V)

The compounds with the substituents R = -OH, -NH ₂ , -NHCH ₃ , -NHCH ₂ CH ₃ and -N are used.

turned

The agent used contains 0.05% active ingredient (compound of formula V), 0.002% surfactant (ethoxylated nonylphenol or alkyl sulfonate) and! V / asser as solvent. To treat the plants (Tomatanbestand in the greenhouse) are simple Handzerstäuber, .r.it with which the agent is sprayed until dripping on the leaves; In the test, groups of at least 10 tomato plants are treated, with one treatment each on the 4th, 3rd, 2nd and 1st day before the infection.

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The inoculation of the pathogen (Corynebacterium michiganense pv. Michiganense (Smith) Oensen) is carried out in the test procedure one day after the last active substance application by spraying an exciter suspension (exciter concentration:

5 X 10 cells / ml); Other known inoculation methods may be used, e.g. B. injection of the exciter suspension.

For the quantitative assessment of the infestation, the usual 9-step rating scheme is used (see, for example, SCHWANNECKE, H .: Studies on the resistance testing of tomatoes against Corynebncterium michigonense, Diss. Halle / Saale 1983). Ee the average infestation intensity (degree of infestation BN) is determined.

Increasing the resistance of tomatoes to bacterial wilt

formula V - -OH CH ₃ Substi tuent -NH _{2 2} CH OH) (R) -NHCH ₃ -NHCH ₂ -N (CH

degree of infestation

C. michiganense

(% of control)

Induced disease resistance

36.8 26.3 28.9 34.2 31.6

63.2 73.7 71.1 65.8 68.4

When using the compositions of the invention is given by activating the plant's own defense systems, a reduction in the susceptibility (increased resistance) in susceptible tomato plants to the bacterial wilt (C. michiga-) 60 ... causes 70%.

Embodiment 2:

Improving the resistance of cucumbers to the angular leaf blotch disease (Pseudomonas lachrymans)

Cucumber plants (Cucumis sp.) / Which are susceptible to angular leaf spot disease (Ps. Lachrymans) are present with the composition according to the invention containing as active component a compound of formula V (R = -OH and -NHCH ₂ CH ₃ ) injected with an infection; the treatment in the test is carried out according to Example 1. Application concentration of the active ingredient: 0.05% - in aqueous solution.

The pretreatment of the plants is carried out on four successive days in the 2 to 3 leaf stage stage; on the fifth day inoculation with a Pseudomonas lachry

Mans · suspension (5 × 10 cells / ml) by the usual injection technique. It is the infestation strength - measured by the number of disease-related leaf spots and their size - determined.

In the treated plants, the number of leaf spots is reduced by 50 ... 60%, based on the control. The remaining leaf spots are reduced in size by an average of 70%.

The compounds of the present invention are effective for reducing the susceptibility to angular leaf spot disease.

Claims (4)

- ie - invention claim 1. A means for inducing resistance to bacterial pathogens in crops and useful plants, characterized in that in addition to conventional adjuvants and additives as an effective ingredient, a compound of the general formula ^{1 1 3} A A R ₂ JI J_NH_f ^ -CH = CH- / y NH-II IR. Il SO ₃ X SO ₃ X (Formula I) in which X is Na, K, NH ₄ or aliphatic amine and R. to R _{4 are} different or in pairs R ₁ + R ₃ and R ₂ + R _{4 are} each the same or R ₁ to K _{4 are the} same means Cl, -OM, -NH ₂ - Aliphatic primary or secondary amines having preferably one to four carbon atoms, which may further carry oxy or oxyalkyl groups - cycloaliphatic amines qjj qjj Heterocycles, such as ~ "N ^ CH ₂ -CHJ - 17 - - Where appropriate, substituted aromatic amines or phenols, in particular of the compound strain benzene or naphthalene, their substituents z. B. Cl, -CH ₃ , -CH ₂ -CH ₃ , -OCH ₃ si'idj R "means either R ₁ or eii substituted aromatic amine of the general formula SO ₃ X (Formula IJ.) wherein X has the meaning given above and Z is -H-Cl or -SO ₃ X stohti Furthermore, R "means a compound of the general formula SO ₃ X (Formula III)
where for X and Z the meaning given gi11 may also be a substituted aromatic amine of the basic structure ι \ / ι v »" WW ^; ZX ZX (Formula IV) in which likewise X and Z have the meanings given above and are either in the ring A or B in pairs or isolated in such a way that at X in the ring A with the above-mentioned meaning then X in the ring B is -H and vice versa ^ ftasselbe applies for Zf R ₁ to R different, the substituents correspond to the entire possibilities of R. and R ₂ . 2. Composition according to Anspruc'n 1, characterized in that a mixture of different Stilbenderivate is used according to claim 1. 3. Composition according to claim 1 and 2, characterized in that it contains surface-active substances, inert Träger.substanzon and / or solvent. 4. Composition according to claim 1, 2 and 3, characterized in that it additionally contains agrochemicals such as agents for the chemical influence or control of plant development and growth processes (growth regulators, etc.), herbicides, insecticides, fungicides and fertilizers.