DE10065271A1 - Process for combating fire blight and bacterial fire - Google Patents

Abstract

A method for combating the fire blight pathogen Erwinia amylovora, or a bacterial blight pathogen such as Pseudomonas syringae pv. Syringae , or Pseudomonas Syringae pv morsprunorum , or a bacterial blight pathogen, whereby Erwinia amylovora and/or the bacterial blight pathogen is/are treated with slaked lime is disclosed. The slaked lime can thus be applied in the form of a (preferably saturated) aqueous solution.

Description

The fire blight is still serious in Germany and other countries problem. Due to the legal in Germany Limitation to 2-3 treatments per vegetation with the usually on put antibiotic streptomycin sulfate occurs in infestation years with more frequent Favorable conditions occur (start of incubation period) during flowering period of massive fire blight (Berger F. (1996): Studies on the Epidemiology of the fire blight Erwinia amylovora ((Burrill) Winslow et al.) Below paying special attention to the prognosis of the disease. - Dissertation in the subject rich horticulture at the University of Hanover. 1-258.). Antibiotics are from ver different sides critically. Both those responsible for environmental protection and Plant protectionists and doctors fear that resistance may develop in Erwinia amylovora itself and in epiphytes (Knoll G. (1997): International studies on Formation of resistance of the fire blight pathogen Erwinia amylovora, antibiotic use for  Firefighting in fruit growing, risk-alternative cost documentation a public event organized by the parliamentary group 'Bündnis 90 / Die Grünen' Hearing on the topic of 'fighting fire blight in fruit growing', - NABU Landesver band Baden-Württemberg e. V., 24-25 .; Hasler T., Vogelsanger J., Schoch B. (1997): Fire blight in Switzerland in 1995, antibiotics used in the fire Firefighting in fruit growing, risk alternative cost documentation organized by the parliamentary group 'Bündnis 90 / Die Grünen' Hearing on the topic of 'fighting fire blight in fruit growing', - NABU Landesver band Baden-Württemberg e. V., 32-35.). On the part of the beekeepers there were values submitted after the limit for streptomycin in honey at Lake Constance was partially exceeded. The use of bactericides should affect everyone professional groups and not unilaterally at the expense of one Professional group are enforced. That is why a search for cheap replacements is necessary products for combating fire blight and disinfecting the cut tools necessary. Similar considerations apply to bacterial fire.

It was therefore the object of the present invention, a method for combating the fire blight pathogen Erwinia amylovora or a bacterial fire pathogen such as Pseudomonas syringae pv. syringae or Pseudomonas syringae pv. mor to specify sprunorum, which does not require the use of an antibiotic and leads to economically and ecologically acceptable control results.

This problem is solved by specifying a method in which Erwinia amylovora and / or the bacterial fire exciter is treated with hydrated lime. For Treatment of plants by Erwinia amylovora or a bacterial fire agents such as Pseudomonas syringae pv. syringae or Pseudomonas syringae pv. morsprunorum are infested, accordingly the plants are hydrated applied.

The slaked lime is advantageously in the form of a (preferably saturated)  aqueous solution on the pathogen or the carrier carrying the pathogen or from plants endangered to him.

Another aspect of the present invention relates to the use of Slaked lime as a means of combating the fire blight pathogen Erwinia amylovora and a bacterial fire exciter such as Pseudomonas syringae pv. syringae or Pseudomonas syringae pv. Morsprunorum; this also includes disinfection of Objects (e.g. cutting tools such as knives, tree cutters or boots) or parts of the body (especially hands) that are in contact with one of the pathogens mentioned Are in contact.

Further details and preferred embodiments of the present invention can be found in the following test report, which relates to the Combat Erwinia amylovora limited. With regard to Pseudomonas sy ringae pv. syringae and Pseudomonas syringae pv. morsprunorum are the treatments results analogously.

Investigation report material and methods

As a standard agar medium for plating experiments, MSA mod. (Brulez W. and Zeller W. (1981): A new method for predicting the fire blight (Erwinia amylovora). - Mitt. Biol. Bundesanst. 203, 112.) used. To grow the Erwinia Amylovora bacteria was used in Nutrient Sucrose Calcium Medium (NSC) and let the bacteria grow as an overnight culture.  

Culture media used MSA mod. (Brulez and Zeller 1981, loc. Cit.)

Nutrient broth 8 g Sucrose 50 g Agar 20 g 0.5% bromothymol blue solution (in 98% ethanol) 9 ml 0.5% neutral red solution 2.5 ml H ₂ O dest. 1000 ml

Nutrient sucrose calcium medium (NSC)

Nutrient broth 8 g Sucrose 50 g Ca carbonate CaCO3 50 g H ₂ O dest. 1000 ml

Agar diffusion test

On the MSA mod. Plates were pipetted 10 ul of an overnight culture (10 ⁹ cells / ml), grown in NSC, and evenly distributed with Drigalski's spatula. After the suspension had dried, 10 μl of the solution to be tested was pipetted at 3 different points on the plate and allowed to dry. The zones of inhibition were evaluated after the Erwinia amylovora colonies had grown as lawn on the plate. 20 agar plates were used per treatment.

Surface treatment of the agar plates

On the MSA mod. Plates were 10 µl of an overnight culture, grown in NSC, and pipetted 200 µl of the corresponding solution for wetting and with Drigal Ski spatula evenly distributed. 10 agar plates were used per treatment.  

Treatment of overgrown plates

Agar plates with dense Erwinia amylovora turf were made with the appropriate Solutions layered. After different times, immediately after overlaps, after 5 minutes, after 15 minutes and after 30 minutes after covering was spread over the entire agar plate with an inoculation loop to prevent infectious To be able to record material. The material was then changed back to MSA mod. streaked and rated after growth of the comparison plates.

Treatment of plants

In an orchard (Karlsruhe) in the middle of a fire blight reservoir (infested Orchard stands) were 100 m pears of the varieties' Conference 'and,' Williams Christ 'and 100 m of' Idared 'apples with saturated hydrated lime solution (1.7 g / l) (500 l water / m crown height) during flowering according to the ANLAFBRA forecast (Berger 1996, loc. Cit.). Then there was only one for the apples Treatment with Captan and pears with Dicloflua fungicide nid, followed by four sprays with saturated hydrated lime solution, each shortly after a rain event. Insecticide was not sprayed in the Löschkalkva riante still in control.

Results and discussion

As can be seen from Table 1, a comparable inhibition zone could be achieved with saturated extinguishing lime solution with 5.9 mm and weak lactic acid solution (1.5%) with 7.4 mm as with the 70% ethanol commonly used in bacteriology with 6 , 2 mm. Higher concentrations of hydrated lime (Ca (OH) ₂ ) or acid also increased the average inhibitory zone, so that at a concentration of 20 g / l hydrated lime an inhibitory zone of 12.5 mm, with a 5% lactic acid solution, an inhibitory zone of 13 mm and with household vinegar with 5% acetic acid, an inhibition zone of 12.1 mm can be achieved. The even higher concentrations of lactic acid with 10 and 15% with an inhibition zone of 15.9 and 16.3 mm were comparable with the commonly used antibiotic streptomycin sulfate with an inhibition zone of 16.4 mm.

After the various substances had been completely plated out, inhibited growth was found in 70 percent ethanol, in saturated hydrated lime solution (Ca (OH) ₂ 1.7 g / l) and in 1.5 percent lactic acid solution (Table 2). Higher acid concentrations from 5% lactic acid or higher concentrations of hydrated lime from 20 g / l disinfected completely. Even normal household vinegar led to the same success. The effects of higher acid concentrations and hydrated lime concentrations were comparable to those of streptomycin sulfate (plantomycin 0.06%).

After covering layers of grown Erwinia amylovora cultures, the the necessary exposure time, however, is very long. So with household vinegar and with Lactic acid content from a level of 5% only after an exposure time of 15 Minutes the colonies are killed. In the disinfectant practice 70 percent ethanol used by cutting tools was only after 30 Minutes of exposure, the colonies died. The different hydrated lime The results are comparable to ethanol. In case of overlays with streptomycin sulfate, the colonies were still after 30 minutes of exposure alive (Table 3).

As can be seen from the results, Erwinia amylovora at Be fight between bacteria with protective and without protective cover or Slime can be distinguished.

In the case of bacteria without a shell, an inhibition zone of different sizes can be achieved depending on the preparation. The rather small inhibitions with the common ethanol and saturated hydrated lime solution can U. can be attributed to the rapid evaporation of ethanol or quick neutralization of hydrated lime through the CO ₂ content of the air. Even with the low lactic acid concentration, this is u. U. can be attributed to the dilution in the medium by diffusion. The fact that the ethanol commonly used worldwide for disinfection in fire blight is not necessarily the best solution has already been brought up from Switzerland (Vogel sanger J. (1995): disinfection of knives, pruning shears, Boots and hands after contamination by fire blight Erwinia amylovora.- Phytomedicin 25, 2, 8; Hasler T., Vogelsanger J., Schoch B. (1996): Disinfection of fire blight contaminated tools. Acta Horticulturae 411, 369-371) reported. With higher concentrations of hydrated lime or acid, however, greater inhibition levels could also be achieved. Slaked lime in suspension apparently has a longer dwell time until it is completely neutralized. At higher acid levels, the agar is also more strongly penetrated by the diffusion and can have a longer effect since the acid is not neutralized by the air, in contrast to the hydrated lime. It is also interesting when plating over the surface that ethanol and saturated extinguishing lime solution are not completely sufficient for disinfection. It is interesting, however, that when higher concentrations were used, the pathogen was completely killed. However, the fact that the bacterial colonies with a mucous membrane could not be killed by brief disinfection and were alive even after a long exposure to streptomycin sulfate makes it clear that the control strategy must therefore be reconsidered. The cancers, cancerous dead wood caused by the fire, but expel bacteria with mucous membranes. That is, A long exposure time of hydrated lime could also minimize the output of living bacteria, at least hydrated lime could also be used to disinfect cut-out canisters.

These studies confirm the results of Hasler et al. (1996), op. Cit., That fire blight cannot be adequately combated with ethanol can. Therefore Vogelsanger (1995), loc. Cit., And Hasler et al. (1996), loc. Cit., disinfection of cutting tools with hot water is recommended.

These results also have consequences for plant control. It becomes clear that with none of these preparations fire blight bacteria with a mucous membrane can be quickly and directly killed. Acid preparations also have the problem of being phytotoxic. However, these results also make clear part of the mechanism of action of bacterial antagonists, which can convert sugar into acid. Slaked lime in the higher concentrations has already been successfully used in New Zealand to control scab (Venturia inaequalis) (Beresford RM, Wearing CH, Marshall RR, Shaw PW, Spink M., Wood PN (1996): Slaked lime, baking soda and mineral oil for black spot and powdery mildew control in apples. Proc. 49 ^th NZ Plant Protection Conf. 106-113.) and in Australia against pear scab (Venturia pirina) (Washington WS, Villalta O., Appleby M. (1998): Control of pear scab with hydrated lime alone or in schedules with other fungicide sprays. Crop. Protection Vol. 17 No 7. Pp. 569-580) can be used. The lime lime fertilizer also proved to reduce the infestation of lice, which are to be regarded as vectors for bacteria with a mucous membrane, especially during fire blight. So, with extinguishing lime, the incidence of fire blight can also be reduced indirectly by killing the lice and pear leaf suckers. In the orchard described above, the proportion of lice and pear leaf suckers was significantly reduced in the hydrated lime variant. No phytotoxic reactions could be determined, which also coincides with the results from Australia and New Zealand. Later there was no fire and hardly any scab in the treated rows. In contrast to the control, the infestation of apple mildew was reduced but not completely combated. To mitigate, however, it must be mentioned that bacterial antagonists were used in the other series to combat the fire blight, which, as known from earlier publications, could also be carried into the hydrated lime variant by the honey bees (Berger F., Frehland E., Köstler N., Pick T., Schuster M., Wesche J., Zeller W. (1999): Biocontrol of fire blight with bacterial antagonists. - Acta Hort. 489, 607-610). Laboratory tests have also shown that these antagonists, like Erwinia amylovora, are killed on the plate. So there is only the possibility of colonization after neutralization of the hydrated lime on the leaf.

In summary, it can be said that a fight against the fire blight by  Use of slaked lime, for example in a concentration of 20 g / l Prolongation of action, in fruit orchards or with antagonists is possible. in the The helicopter can or can spread orchards when spreading hydrated lime Bees are used as vectors for antagonists. The application of the Antagonists with honeybees were very effective in New Zealand (Vanneste J L, Cornish D A, Voyle H M H, Goodwin R M (1999): Honey bees to distribute benefi cial bacteria to apple and Asian pear flowers. Acta Hort .: 489, 615-618). The The values determined show that after a year of trial, good and beautiful Fruits were achieved without high plant protection efforts. The fact that but the fertilizer hydrated lime Erwinia amylovora bacteria without mucous membrane successfully fought on the plate and phytotoxic reactions in their own experiment and are not known from New Zealand and Australia either, it makes one preventive treatment against fire blight.  

Table 1

Average size of inhibition zones after agar diffusion test 10 µl bacterial shake culture and 10 µl solution per point

Table 2

Effect of various substances (200 µl) on Erwinia amylovora suspensions (shaking culture MB) 10 µl

Table 3

Effect of various substances on Erwinia amylovora colonies depending on the exposure time after overlaying the colonies

Various preparations such as the ethanol commonly used for disinfection Lactic acid used in food technology and commonly used Household vinegar and the fertilizer hydrated lime were compared to that in the Practice used streptomycin sulfate tested.

Both the preparations with low pH and the streptomy were shown cinsulfate, lactic acid in various concentrations and household vinegar, as hydrated lime with a high pH at a high concentration is also sufficient Effect on Erwinia amylovora bacteria in aqueous solution, d. H. without rubble zende Levan or Amylovoran shell of the bacteria.

For cultures that have already grown, i.e. H. with protective Levan or Amylovoran The cultures could only cover the substances, if at all, after one quite a long exposure time. With lactic acid in different con concentration and household vinegar, the exposure time was 15 minutes. around the bacteria To kill envelope. With hydrated lime in saturated solution and higher and with the Disinfection commonly used 70 percent ethanol was 30 min needed to kill. With streptomycin sulfate, however, even after 30 min growing.  

literature

Beresford RM, Wearing CH, Marshall RR, Shaw PW, Spink M., Wood PN (1996): Slaked lime, baking soda and mineral oil for black spot and powdery mildew control in apples. Proc. 49 ^th

NZ Plant Protection Conf. 106-113.
Berger F. (1996): Studies on the epidemiology of the fire blight Erwinia amylovora ((Burrill) Winslow et al.) With special attention to the prognosis of the disease. - Dissertation in the horticultural department of the University of Hannover. 1-258.
Berger F. (1999): Comparison of different systems (or models) to predict the fire blight. - Healthy plants, 51st year, volume 1, 1-9
Berger F., Frehland E., Köstler N., Pick T., Schuster M., Wesche J., Zeller W. (1999): Biocontrol of fire blight with bacterial antagonists. - Acta Hort. 489, 607-610.
Brulez W. and Zeller W. (1981): A new method for forecasting the fire branch of (Erwinia amylovora). - Mitt. Biol. Bundesanst. 203, 112.
Hasler T., Vogelsanger J., Schoch B. (1997): Fire blight in Switzerland in 1995, use of antibiotics to fight fire blight in fruit growing, risks - alternative costs - documentation of an event organized by the parliamentary group 'Bündnis 90 / Die Grünen' public hearing on the subject of 'fighting fire blight in fruit growing', - NABU Landesverband Baden-Württemberg e. V., 32-35.
Hasler T., Vogelsanger J., Schoch B. (1996): Disinfection of fire blight contami nated tools. Acta Horticulturae 411, 369-371
Knoll G. (1997): International studies on the development of resistance of fire blight Erwinia amylovora, use of antibiotics to fight fire blight in fruit growing, risk-alternative costs - documentation of a public hearing on the topic organized by the parliamentary group 'Alliance 90 / The Greens' Firefighting in fruit growing ', - NABU Landesverband Baden-Württemberg e. V., 24-25.
Vanneste JL, Cornish DA, Voyle HMH, Goodwin RM (1999): Honey bees to distribute beneficial bacteria to apple and Asian pear flowers. Acta Hort .: 489, 615-618.
Vogelsanger J. (1995): Disinfection of knives, secateurs, boots and hands after contamination by the fire blight pathogen Erwinia amylovora. - Phytomedicine 25, 2, 8
Washington WS, Villalta O., Appleby M. (1998): Control of pear scab with hydrated lime alone or in schedules with other fungicide sprays. Crop. Protection Vol. 17 No 7. PP 569-580.

Claims (4)

1. A method for controlling the fire blight pathogen, Erwinia amylovora, or a bacterial blight pathogen such as Pseudomonas syringae pv, or syringae Pseudomonas syringae pv. Morsprunorum, characterized in that Erwinia amylovora and / or the bacteria is treated with slaked lime blight pathogen. 2. Process for the treatment of plants by Erwinia amylovora or a bacterial fire like Pseudomonas syringae pv. syringae or Pseudomonas syringae pv. Morsprunorum are infected, characterized in that slaked lime is applied to the plants. 3. The method according to claim 1 or 2, characterized in that the hydrated lime in the form of a (preferably saturated) aqueous solution is applied. 4. Use of slaked lime as a means of fighting the fire blight Erwinia amylovora and a bacterial fire like Pseudomo nas syringae pv. syringae or Pseudomonas syringae pv. morsprunorum.