WO1997033477A1

WO1997033477A1 - Plant fungicidal and bactericidal composition comprising aluminum ions

Info

Publication number: WO1997033477A1
Application number: PCT/IL1997/000086
Authority: WO
Inventors: Yoram Tsivion
Original assignee: LEKET BAR CHEMICALS Ltd
Current assignee: LEKET BAR CHEMICALS Ltd
Priority date: 1996-03-13
Filing date: 1997-03-10
Publication date: 1997-09-18
Anticipated expiration: 1998-09-13
Also published as: IL117458A; IL117458A0; AU2228397A; AR006203A1

Abstract

Compositions for controlling plant fungal or bacterial diseases comprising aluminum chelates or a mixture of chelated aluminum and chelated other polyvalent ions. A wide variety of pathogenic fungi as well as pathogenic bacteria may be efficiently controlled by application of aqueous composition of aluminum chelates or a combination of such chelate with chelates of a metal such as zinc.

Description

PLANT FUNGICIDAL AND BACTERICIDAL COMPOSITION COMPRISING ALUMINUM IONS

FIELD OF THE INVENTION

The present invention is generally in the field of pest control and plants. More particularly, the present invention relates to composition and method for use in combatting fungal or bacterial pests in plants.

BACKGROUND OF THE INVENTION AND PRIOR ART

Fungal and bacterial infestation in plants, and particularly of aerial parts of the plants, such as leaves, stems, flowers, fruits, etc., is a major problem in agriculture and combatting of such infestation is necessary to ensure good crop yield. Post-harvest infestation of bacteria or fungi is also a major problem in some crops and control of such infestation is also of high economic importance. While a variety of antifungal and antibacteri¬ al preparations for applications on plants are available, most utilize various toxic substances as the active ingredients and their use may thus have various hazardous and environmental consequences. Accordingly, in recent years many attempts have been made to develop environmentally safe pesticides. Furthermore, most fungicidally active agents, e.g. a variety of azoles, are synthetic compounds which are often expensive to produce.

Copper, manganese and zinc ions have been known to have an antifungal activity (Jane D. Horsfall, 1956, Principles of fungicidal action, Chronica Botanica Company, Waltham, Mass., U.S.A., pp 145-153; George N. Agrios, 1970, Plant Pathology, Academic Press, New York, NY, U.S.A., pp 192-193; Japanese Patent Application Kokai 73/75,724 (abridged in CA 80:104871c); Israel Patent No. 97676). In Israel Patent No. 97676, the copper, manganese and zinc ions were provided in the form of citric acid chelates. _ "> _

GENERAL DESCRIPTION OF THE INVENTION

It is an object of the present invention to provide a novel antifungal or antibacterial preparation for use in plant protection.

It is furthermore an object of the invention to provide a method for combatting fungal and bacterial infestation of plants.

The present invention provides, by a first of its aspects, a plant fungicidal or bactericidal composition comprising an effective amount of aluminum ions (Al⁺³) as an active ingredient and a chelating agent.

The term "effective amount" denotes an amount of an active ingredient which is effective in achieving the desired effect, i.e. antibacterial or antifungal activity.

While chelated Al⁺³, as a sole active agent, was found to be highly effective against fungus, in order to impart an effective antibacterial activity the aluminum ion is preferably combined with a synergistically effective amount of another polyvalent metal ion, preferably zinc (Zn⁺²). A typical effective amount of Al⁺³ is in the range of 1.9-6 mM, preferably within the range of 2.8-6 mM. Where the composition comprises both AT³ and Zn⁺², an effective amount of these two metal ions is as follows:

Al⁺³ : about 10.6 - 4.0, preferably about 1.2 - 3 mM; Zn⁺² : about 10.9 - 5.0, preferably about 3.5 - 4.5 mM.

A preferred chelating agent in the composition of the invention is citric acid. Effective chelation using citric acid is achieved with a molar ratio of citric acid to all the metal ions being about 0.8 to about 2.0, a ratio of about 1.0 to about 1.5 being particularly preferred. In addition to citric acid, also useful as chelates in the composi¬ tion of the invention are gWcine, sulfosalicylic acid resorcinol and others.

The compositioii of the present invention may at times also comprise surfactants such as Tritox X-100.

The composition of the present invention may be prepared from a precursor composition, which may either be a liquid concentrate or a dry particulate solid. Such a concentrate or particulate solid also constitutes an aspect of the invention. The present invention also provides a method for combatting plant fungal or bacterial infestation of plants or plant parts, comprising adminis¬ tering on to the plants or plant parts an effective amount of Al⁺³ chelate, optionally in combination with a Zn⁺² chelate. The composition and method of the present invention may be used for prophylactic treatments of plants, may be used for acute treatment of infestations, and may also be used for post-harvest protection of fruits or other crops, against bacterial of fungal infection. The composition may be applied to plants by spraying, through the irrigation system, by dipping, etc., as generally known per se. For post-harvest protection, the crops may be sprayed or dipped in the composition.

The present invention will now be illustrated with reference to the following non-limiting examples.

Example 1

A composition comprising 1.17 M A1C1₃, in which the Al⁺³ was chelated completely by citric acid at equal molarity was prepared.

The preparation was mixed with a growth medium that supports fungal growth which was potato dextrose broth comprising 200 g potato extract and 20 g bacto dextrose in 1 liter of water, and added into a petri dish. The petri dishes were then inoculated by standard amount with the fungi Penicillium digitatum, the culture was incubated at 22°C, and a colony diameter (in cm) was measured at specific time periods. The results are shown in the following Table I:

Table I

Colony Diameter¹

Concentration² 2 Days 3 Days 7 Days of inhibitor

Control 0.87 1.33 2.17

0.2% 0.90 1.55 1.92

0.5% 0.67 0.6 1.52

1% 0.13 0.00 0.00

1.5% 0.00 0.00 0.00

2% 0.00 0.00 0.00

¹ Colony diameter in cm.

² Concentration of inhibitor - % (v/v) of original preparation in the tested medium.

The above results clearly show the high efficacy of the composi¬ tion of the invention in inhibiting of fungal growth.

Example 2

The same preparation as in Example 1 was tested for its effect on Botrytis cinerea. The results are shown in the following Table II.

- D -

Table II

Colony Diameter¹

Concentration² 2 Days 3 Days 6 Days of inhibitor

Control 4.58 8.38 9.00

0.5 % 1.43 1.40 1.98

1.0 % 0.57 0.00 0.00

1.5 % 0.87 0.00 0.00

2.0 % 0.00 0.00 0.00

2.5 % 0.58 0.00 0.00

^{1 2} See Table I

Here again, the efficacy of the inventive composition in inhibiting fungal growth is demonstrated.

Example 3 The following preparations were tested:

Preparation A: 0.82 MnS0₄, 0.58 M A1C1₃, and 1.4 M citric acid (as a chelating agent). Preparation B: 1.9 M AIC1₃, and 1.9 M glycine (as a chelating agent). Preparation C: 0.8 M CuSO₄ and 0.8 M sulfosalicylic acid (as a chelating agent).

Preparation D: 0.9 M ZnNO₃, 0.58 M A1C1₃ and 1.47 M citric acid.

The bacteria Erwinia sp. was isolated from potatoes and identified. Aqueous solutions of preparations A-D were introduced at a variety of concentrations in sets of flasks containing liquid growth medium. Bacteria at standard amount were inoculated into each of the flasks, the flasks were continually shaken and incubated at room temperature. 24 Hours after the onset of incubation, an O.D. reading was taken, and the results are shown in the following Table III.

Table III

Concentration¹ preparation # 0.00% 0.10% 0.5% 1.00% 1.5% 2.00% preparation A 1.188 1.180 0.000 0.196 0.000 0.000 preparation B 1.179 1.110 1.081 0.936 0.248 0.000 preparation C 1.180 1.160 1.220 0.253 0.320 0.275 preparation D 1.140 0.150 0.000 0.000 0.000 0.000

¹ Concentration - %(v/v)

The results show the efficacy of aluminum containing prepara¬ tions (A and D) to totally inhibit bacterial growth and at a 2.0% concentra¬ tion. Furthermore, the results demonstrate the particularly high efficacy of preparation D which contained both zinc and aluminum ions in totally inhibiting bacterial growth even at a concentration of 0.5%.

Example 4

The same preparations of Example 3 were tested in their ability to inhibit growth of Botrytis cinerea in tissue culture wells. The fungi were grown under the same conditions as described for Penicillium digitatum in Example 1.

After two days, the cultures were viewed and each well was given a score based on the amount of final growth as follows:

+++ - more than 100% growth; ++ - -50% growth; + - -10% growth; 0 - no growth.

The results are shown in the following Table IV.

Table IV

Concentration¹ preparation 0 0.05% 0.1% 0.2% 0.5% 1.0% preparation A +++ +++ +++ ++ + 0 preparation B +++ +++ ++ 0 0 0 preparation C +++ +++ +++ ++ 0 0 preparation D +++ +++ + + 0 0

See Table III

Here again, the most effective one was preparation D.

Claims

CLAIMS:

1. A plant fungicidal or bactericidal composition comprising an effective amount of aluminum ions (Al⁺³) as an active ingredient and a chelating agent.

2. A composition according to Claim 1 comprising a synergistically effective amount of another polyvalent metal ion.

3. A composition according to Claim 2, wherein the other metal ion is zinc.

4. A composition according to any one of Claims 1-3, wherein the chelating agent is citric acid.

5. A concentrate or solid for the preparation, by mixing with water, of the composition of any one of Claims 1-4.

6. A method for combatting plant fungal or bacterial infestation of plants or plant parts, comprising administering on to the plants or plant parts an effective amount of Al⁺³ chelate, optionally in combination with a Zn⁺² chelate.

7. A method according to Claim 6, for the prophylaxis of bacterial or fungal infestation of plants or parts of plants.

8. A method according to Claim 6, for the treatment of bacterial or fungal infestation of plants or parts of plants.

9. A method according to Claim 6, comprising post-harvest crop treatment.