EP2068627A1

EP2068627A1 - Agent for treating and/or preventing fire blight

Info

Publication number: EP2068627A1
Application number: EP07820485A
Authority: EP
Inventors: Johannes Gareiss; Georg Geraedts; Hans Siebenlist; Ulf Abele
Original assignee: Lanxess Distribution GmbH
Current assignee: Lanxess Distribution GmbH
Priority date: 2006-09-27
Filing date: 2007-09-24
Publication date: 2009-06-17
Also published as: WO2008037677A1; DE102006045505A1; CL2007002756A1; US20100056630A1; CA2664493A1; AU2007302023A1; IL197533A; AR062939A1; US20130237601A1; IL197533A0

Abstract

The invention relates to an agent for treating and/or preventing fire blight, particularly present in wood and fruit trees, comprising formic acid and/or a salt of formic acid, particularly calcium formiate as an active component. Further disclosed is the use of formic acid and/or a salt of formic acid, particularly calcium formiate as an active component in herbicides, particularly for treating and/or preventing fire blight, and the use of formic acid and/or a salt of formic acid, particularly calcium formiate, for the production of an agent for treating and/or preventing fire blight.

Description

Means for the treatment and / or prevention of fire blight

The invention relates to an agent for the treatment and / or prevention of fire blight, especially in woody plants and preferably in fruit trees, which contains formic acid and / or a salt of formic acid, in particular calcium formate as an active ingredient. It further relates to the use of formic acid and / or a salt of formic acid, in particular calcium formate as an active ingredient of crop protection agents, in particular for the treatment and / or prevention of fire blight, and the use of formic acid and / or a salt of formic acid, in particular calcium formate for the production a means of treatment and / or prevention of fire blight.

background

Fire blight is a disease caused by the bacterium Erwinia amylovora of fruit and ornamental shrubs. The disease is notifiable.

The disease was first detected in apples, pears and quinces in the eastern United States 200 years ago. It first appeared in England in 1957. Here, the bacterial pathogen was detected. In recent decades, the disease has spread widely and now represents a serious threat to pome fruit and ornamental species. Since 1993, it has spread to orchards in southern Germany and caused devastating damage. Affected are the commercial fruit growing, landscape-forming strawberry cultivation as well as nurseries, home gardens and the public green. The disease is dangerous and extremely difficult to control.

The host plant circle is limited to apple-fruited rose plants (Pomoideae or Rosaceae). The pathogen has been detected in numerous genera and species of this family. For northern and central Europe are considered host plants, the cultivated and ornamental forms of apple (malus), and pear (Pyrus) and firethorn (Pyracantha), quince (Cydonia), Stranvesia (Stranvesia), Sorbus species such as the rowan (Sorbus), White and red thorn (Crategus), ornamental quince (Chaenomeles), cotoneaster (Cotoneaster), loquat (Eriobotrya) and the medlar (Mespilus). The severity of the attack depends very much on the weather during the flowering phase of each variety.

The bacteria survive the dormancy in diseased bark parts. From here, in spring and summer, it is spread by raindrops, wind, and sucking and bleeding visiting insects such as bees, aphids, leaf suckers, wasps, bumblebees and flies. Birds should also play a role in the distribution. The disease usually begins with a floral infection, which can then lead to annual sales of massive infestation of other parts of plants (shoots). Important entry ports for the pathogens are open flowers and wounds, with sufficient moisture and natural openings such as nectaries, stomata, lenticels and scars of leaf and fruit stalks.

Diseased flowers, shoots and fruits wither. They turn brown at first, later mostly black at the infestation sites. From these sites of infection, the disease can spread to adjacent shoots, stronger branches and the trunk. The disease is often fast and intense. The affected plants look like they are burned or withered. typical

Characteristics of the fire blight disease are usually dark brown to black colored stalks of dead flowers and leaves on the diseased branches and the often striking dark colored main veins on the leaves. The dead, dried leaves and fruits stick to the trees. The diseased initially pale green-looking young shoot tips often curl as a result of lack of water kruckstockartig. In late-flowering shrubs and secondary flowers, there is a high risk of infection even in summer. The shoots can also be infected throughout the growing season, especially before the end of the shoot. In spring and summer, moist, initially colorless, later brown-colored sticky droplets appear on the affected shoots, fruits and documents. This infectious bacterial mucus (exudate) is abundantly produced especially in hot and humid conditions. In addition to the droplets, thread-like structures can also occur. In winter, but often in the summer or fall, small to larger dead spots on the trunks and thicker branches can be seen. ("The fire blight endangers fruit and ornamental shrubs", plant protection service, state institute for plant protection, Stuttgart 2000/2003).

As a measure of control of the fire blight, it is especially recommended to have regular checks for timely detection and immediate removal of affected plant parts when the first symptoms appear. The removed parts must be burned immediately. Care should be taken that the tools used are thoroughly disinfected, as they can also be removed by tools, e.g. Lopping shears or saws, a transfer can be made. Care must also be taken that no other host plants are touched with the removed parts of the plant. Heavily affected plants must be completely cleared and destroyed immediately.

These measures, z. T. have led to rigorous clearing of large fruit areas, but have proved to be insufficient.

The use of conventional pesticides is usually insufficient for the treatment of fire blight. For example, resistance inducers (bionic Acibenzolar-S-methyl, Regalis- Prohexadione-Ca, Phosfik - phosphorous acid), bacterial antagonists based on Pseudomonas fluorescens (A 506) and Bacillus subtilis (Biopro, FZB, Serenade), minerals (mycosin, kaolin, tea), disinfectants (cetylpyridinium chloride, Menno Florades, hydrogen peroxide ), Bactericidal side effect fungicides (Dithane-Mancozeb, Win-capronamide), copper preparations and combinations of resistance inducers with bacterial antagonists. None of these agents showed sufficient effect. (E. Moltmann, "Feuerbrandbekämpfung in Baden- Württemberg", Festschrift 50 Years Landesanstalt für Pflanzenschutz Stuttgart 2005).

EP-A 0 158 074 discloses the use of benzisothiazodioxides known as sweeteners for combating fire blight.

WO 02/052942 describes the control of fire blight by slaked lime, preferably in the form of an aqueous solution.

DE-A 101 41 774 proposes to completely coat the plants with a liquid latex spray, so as to prevent the infestation with fire blight.

CA-A-2291984 and US-A 4569841 disclose the control of fire blight by Erwinia herbicola bacteria, WO 2005/048717 the use of "beneficial" bacteria or fungi for this purpose.

EP-A 0 565 266 discloses a combination of a copper complex and a partially neutralized water-soluble polycarboxylic acid for the control of bacterial or fungal plant diseases.

EP-A 1 075 185 proposes a combination of dodin and anilinopyridine for combating fire blight.

DD-A 273 192 discloses the use of the strepithricin antibiotic nourseothricin to combat fire blight, GB-A 1315430 of an antibiotic "A-201A".

DE-A 3640048 describes nitroalkanols for combating fire blight and also mentions that the use of disinfectants such as benzalkonium chloride is suitable for killing flowers and therefore excludes the most important possibility of infection for fire blight.

EP-A 1300078 proposes natural herbal components selected from tea tree oil, wintergreen oil and eugenol or a mixture thereof, for combating fire blight. US Pat. No. 5,686,389 proposes the use of 5-hydroxylysine or 1,4-diaminobutanone for combating fire blight, and these active compounds are also said to be active against antibiotic-resistant strains.

JP-A 1090102 discloses β-thujaplicin as an anti-blaze agent.

JP-A 63099005 proposes polysixin antibiotics in combination with an imidazole antibiotic for this purpose.

Compound, JP-A-57081404 alkoxycarbonylureidophenyl.

GB-A-1049116 discloses a tetrahydroxypyrimidine derivative in aqueous solution as an anti-firebrand agent which is said to be non-phytotoxic.

However, all these active ingredients do not show satisfactory results in combating fires.

Fairly good results (efficiencies of up to 70%) in the fight against fire blight were achieved with the yeast-containing preparation "Blossom Protect." Yeast fungi are supposed to make plants resistant to pathogens through the use of antagonists.The yeast fungi are also used in nature fruit and are therefore harmless to consumers or the environment (Obstbau 4/2006, 232)

Fruit varieties to an intolerable Fruchtberostung. It is also only partially compatible with fungicides. (E. Moltmann, supra)

The evaporation and the solarization, a special sun exposure by means of black film, also show no sufficient effect.

The focus was therefore on the one hand on the breeding of resistant documents and fruits. There are already numerous plant variety rights for such plant varieties. Genetic engineering of transgenic resistant plants has also been proposed (see, for example, AU-A 670638, US 6100453).

As a last resort, however, it is also possible, under strict regulatory conditions, to use an antibiotic in exceptional cases, namely the streptomycin-containing agent plantomycin (21.1%).

Streptomycin sulfate) (also called Strepto or Firewall 17 WP). With streptomycin flower infections can be warded off by the fire blight with an efficiency of 70 to 90%. (E. Moltmann, supra)

The approval of the antibiotic application in plant production is so far unique in Germany. In Switzerland e.g. the use of streptomycin in plant production is inadmissible.

Treatment with streptomycin is only after obtaining written approval, under Keeping a detailed protocol, observing certain periods of protection before harvest, with a maximum of three applications during flowering, the reference only with a certificate of entitlement, application only in the cultivation of crops and under strict residue control. These measures are intended to minimize the risks that generally arise from the use of antibiotics in agriculture. In particular, the selection and propagation of streptomycin-resistant fire blight strains should be prevented. In addition, there is a risk of the formation of residues of streptomycin in honey, which must therefore be carefully controlled. The economic damage not only for the fruit producers, but also for the beekeepers are significant.

The use of streptomycin for fire blight control is effective overall, but extremely complex and fraught with great risks and disadvantages for the environment and the consumer.

For the application in private gardens and public parks as well as in wild shrubs, in which the fire blight spreads especially by the infestation of the popular ornamental plant Cotoneaster and the hawthorn massively, streptomycin is neither suitable nor permissible. In particular, for these applications, there is no satisfactory means that could fight the fire blight.

Thus, there is an urgent need for a means of combating fire blight, which on the one hand has a high efficiency and on the other hand is not afflicted with the said disadvantages of an antibiotic.

Against this background, the object of the present invention is to provide a

By means of prevention and / or treatment of fire blight.

The invention therefore relates, on the one hand, to an agent for the prevention and / or treatment of fire blight according to claim 1, which contains formic acid and / or a salt of formic acid, in particular calcium formate, as the active ingredient. Preferred embodiments are specified in claims 3 to 5. Furthermore, the use of formic acid and / or a salt of formic acid, in particular calcium formate as an active ingredient in crop protection agents, preferably for use in woody plants and fruit trees in particular claimed. The invention further relates to the use of formic acid and / or a salt of formic acid, in particular calcium formate for the preparation of an agent for the treatment and / or prevention of fire blight.

The agent according to the invention contains formic acid and / or a salt of formic acid, in particular calcium formate as active ingredient. This substance is approved as a food preservative (E238) and therefore completely safe to use. Furthermore, formic acid and / or a salt of formic acid, in particular calcium formate, are permitted as secondary nutrient fertilizers in accordance with the Fertilizers Ordinance.

In addition, the composition may contain other auxiliary substances and additives customary for crop protection agents, such as solid or liquid carriers.

Solvents such as e.g. mono- or polyhydric alcohols surfactants such as anionic

Surfactants, wetting agents, e.g. Alkyl sulfonates, emulsifiers such as e.g. Alkylcarbohydrate esters, dispersants such as e.g. Alkylphenol polyglycol ethers, stabilizers such as e.g. Cellulosic adhesives such as e.g. paraffinic oils, spreading improvers such as e.g. Isopropyl myristate, buffering agents such as e.g. Hydrogen phosphates, weak acids or bases such as e.g. Citric acid or ammonium salts, dyes and perfumes. Furthermore, the agent according to the invention may contain other active ingredients such as fungicides, bactericides, insecticides, acaricides, growth regulators, plant nutrients such as e.g. Contain secondary nutrient fertilizer.

The agent can be formulated in solid or liquid form in the usual way. For example, Formic acid and / or a salt of formic acid, in particular calcium formate with other solid excipients than powders, pellets, granules, capsules or tablets, as desired, also in portions, formulated and packaged, or it is together with the excipients and optionally further active Ingredients in liquid form. The agent according to the invention is preferably formulated together with the auxiliaries and optionally further active ingredients in the form of a dust-free microgranulate, which is then diluted with water to the application concentration immediately before use.

The concentration of formic acid and / or a salt of formic acid, especially calcium formate in the granules is e.g. 50-98%, preferably 70-90%, particularly preferably about 78 to 82% by weight and more preferably 80% by weight, in each case based on the granules.

The granules are then preferably with water to an application concentration of 0.2 to 15 wt .-%, preferably 0.5 to 10 wt .-% and particularly preferably 2.0 to 5.0 wt .-% in each case based on the granules diluted.

The pH of the application solution is from 3 to 6, preferably from 4 to 5.5 and more preferably from 4.5 to 5.

In experiments with an agent according to the invention in apple blots infected with Erwinia amylovora, in concentrations of 5% by weight and 10% by weight, based on the granules, as in

Example 1 described an efficiency in the reduction of fire blight of over 80% achieved, the difference between the two concentrations was not significant. In liquid culture, Erwinia amylovora was completely inhibited in experiments at a concentration of 0.25%. It is therefore to be assumed that a concentration of at least 0.5% is required for the application to flowers, since experience has shown that a higher concentration is required in the flower experiment than in liquid culture.

As an efficiency according to the invention the percentage reduction of infestation is understood against treated with tap water parts of plants.

The agent according to the invention is prepared in the usual way, e.g. by spraying or brushing, preferably by spraying. Preferred is the application to the flowers. The spraying can take place preventively or even in plants already affected by fire blight. The application can be made once or several times at intervals of 1 to 14 days, preferably after 3 - 5 days as needed.

The application is made in all plants sensitive to fire blight, especially in woody plants and particularly preferably in fruit trees such as apple, pear and quince, but also white and red thorn, cotoneaster, medlar and etc. As the agent is completely harmless to humans and the environment, The application can not only be made in commercial asylum plantations, but also in home gardens and public green areas or orchards. Thus, the further spread of fire blight can be easily prevented without any risks to the environment, such as occur when using antibiotics.

To further illustrate the invention, the following examples are given.

example 1

Test for inhibitory activity against Erwinia amylovora

On the culture medium CYE, 10 μl of a suspension of Erwinia amylovora were plated at a density of 108 cfu / ml. Subsequently, a hole of 5 mm in diameter was punched into the middle of the plates and 20 .mu.l of the test solution was added. After 24 hours the Hemmhof was measured. The reference substance used was streptomycin sulfate and as a negative control tap water.

An aqueous solution of the preparation according to the invention in the form of a granulate of formic acid and / or a salt of formic acid, in particular calcium formate, whose content of formic acid and / or a salt of formic acid, in particular calcium formate, was about 80% by weight, was used. This was diluted with tap water to the stated concentrations based on the granules.

Result

Table 1

Example 2

Determination of the dose-response curve of formic acid and / or a salt of formic acid, in particular calcium formate solution in Erwinia amylovora in liquid culture

Erwinia amylovora strain 385 was streaked on nutrient agar plates (nutrient broth) and incubated at 27 ⁰ C. From the plates, a suspension was prepared after two days and the cell count was determined.

For the dose-response curve, graded concentrations of the test preparation (stock solution: 29% by weight calcium-containing aqueous solution) were added to nutrient broth liquid medium, and the inoculations were inoculated with a pathogen count of 107 cells / ml. An approach without a test preparation served as a control. From all approaches, the pH was measured.

After 24 hours of incubation at 27 ⁰ C, the viable count (cfu = colony forming units) were determined by plating on the pathogen Mac-Conkey-Agar in all batches.

After 3 days of incubation at 27 ^° C., the plates were counted and the reduction calculated according to the following equation:

REDUCTION% = (1-cfu / cfu control) x 100

The test solution used was the same solution as used in Example 1, which was diluted with water to the stated concentration (% by weight based on final solution).

Table 2

Up to a concentration of dissolved granules of 0.25%, Erwinia amylovora is 100% inhibited in liquid culture. Thereafter, the curve drops very steeply, at a concentration of 0.125%, almost no effect is present. Example 3

Determination of the effectiveness of formic acid and / or a salt of formic acid, in particular calcium formate solution against Erwinia amylovora on apple blossoms

Apple blossoms of the Gala variety of pot plants set up in the field (not treated with pesticides) were placed with the flower stem in a 10% by weight sugar solution and incubated in a moist chamber. 24 flowers were used per treatment and repetition; the experiment was repeated four times ,

Erwinia amylovora strain 385 was streaked on nutrient agar plates (nutrient broth) and incubated at 27 ⁰ C. From the plates, after two days, a suspension with a bacterial count of 1x106 cells / ml was prepared. For inoculation, the flowers were sprayed with this suspension.

For treatment, the flowers were sprayed one hour after inoculation with the respective solution, the chamber sealed and incubated at 20 -23 ⁰ C for 6 days. One day after inoculation, the flowers were treated with the fungicide Euparen (0.15%) to protect against mold attack.

As the test solutions, solutions as in Example 1 at a concentration of 10% by weight and 5% by weight, a streptomycin sulfate solution (Strepto, 0.06% by weight) and tap water were used as a control. The pH values of the solutions of formic acid and / or a salt of formic acid, in particular calcium formate granules, were between 4 and 5.

After 6 days, the number of flowers was counted with bacteria drops. The percentage reduction in infestation over the tap-treated control was calculated as an efficiency for each treatment.

Table 3

The development of symptoms caused by the fire burners was significantly reduced by both calcium formate concentrations used in the test with efficiencies above 80%. Of the The difference between the two concentrations was not significant, so that the concentration could possibly be further reduced.

The crop protection agent Strepto had a slightly lower efficiency of 73%. However, it was metered 80 times lower at a dose of 0.06 wt .-% streptomycin than in the 5 wt .-% formic acid and / or a salt of formic acid, in particular

Calciumformiatpräparaten.

Claims

claims

1. A means for the prevention and / or treatment of fire blight, characterized in that it contains formic acid and / or a salt of formic acid as an active ingredient.

2. Use of formic acid and / or a salt of formic acid, in particular calcium formate as an active ingredient in crop protection products.

3. Use according to claim 2 for use in woody plants, especially in fruit trees.

4. A composition according to claim 1, which conventional auxiliaries, solvents, emulsifiers, wetting agents, adhesives, agents for improving the Spreitvermögens, binders, means for

Flow control, pH adjuster, complexing agents, stabilizers, antioxidants or dyes.

5. Composition according to claim 1 or 4, which optionally additionally contains one or more further active ingredients.

6. Use according to claim 2 or 3 in combination with one or more further active ingredients.

7. Use of formic acid and / or a salt of formic acid, in particular calcium formate for the preparation of an agent for the prevention or treatment of fire blight.

8. Use according to claim 7 in woody plants, especially in fruit trees.