WO1998058546A1

WO1998058546A1 - Fungicidal and bactericidal compositions for plants containing compounds in the form of heavy metal chelates

Info

Publication number: WO1998058546A1
Application number: PCT/US1998/012264
Authority: WO
Inventors: John B. Taylor
Original assignee: Taylor John B
Priority date: 1997-06-25
Filing date: 1998-06-12
Publication date: 1998-12-30
Also published as: AU743922B2; AU7963598A; NZ501984A

Abstract

The present invention is fungicidal and bactericidal compositions, and methods of use, which provide improved efficacy in controlling parasitic fungi and bacterial infections in plants. The compositions have fungicidally and bactericidally effective amounts of heavy metal chelates in aqueous solution. Such compositions control fungal and bacterial attacks on plants substantially nonphytotoxic.

Description

TITLE

FUNGICIDAL AND BACTERICIDAL COMPOSITIONS FOR PLANTS

CONTAINING COMPOUNDS IN THE FORM OF HEAVY METAL CHELATES

INVENTOR(S)

John B. Taylor

1420 Lemon Street

Deland, Florida 32720-4599

FIELD OF THE INVENTION

The present invention is broadly concerned with fungicidal and bactericidal

compositions, and methods of use, which provide improved efficacy in controlling

parasitic fungi and bacterial infections in plants. More particularly, the

compositions and methods of use of the invention including fungicidally and

bacterially effective amounts of copper compounds in form of heavy metal chelates,

and preferably in the form of Cu-EDDHA, cupric ethylene diamine dio-

hydroxyphenylacetate in aqueous solution).

BACKGROUND OF THE INVENTION

Fungicides, as well as bactericides, are chemical agents used to protect

agricultural crops from those pathogens which, if left uncontrolled, would result in

unacceptable economic losses.

Copper compounds that are active as fungicides and bactericides have been

in agricultural use since the advent of Bordeaux in the grape vineyards of France in

the early 1800's. Many different formulations of fungicides employing copper

compounds, such as wettable powders, water based flowables and dry flowables, are

commonly used today in modern agricultural applications. Such copper compounds, for the most part, have been inorganic in form

when applied to agricultural uses. Organic forms of the copper compounds have

been found to be generally phytotoxic, especially in foliar applications. (Certain

organic copper compounds, however, have some utility as fungicides (e.g.,

CUTRINE Cu salt of triethanole amine) is quite effective as an aquatic algaecide.)

Modern day agricultural use of inorganic copper compounds as fungicides

employ varying forms of copper compounds having relatively low water solubility,

including for example, cupric hydroxide, tri basic copper sulfate and tank mix

combinations (with heavy metal ethylene bis dithiocarbamate fungicides to enhance

the bactericidal activity against certain important agricultural bacteria such as

Xanthomonas, Pseudomonas, and Erwinia).

Water soluble copper compounds such as CuSO₄, though effective to inhibit

germination of fungus spores, cannot be used in foliar applications to agricultural

crops because the cupric ion is extremely phytotoxic. Therefore, relatively

insoluble forms of inorganic copper compounds, such as cupric hydroxide, have

been found to be more effective fungicides. (Not all water insoluble Cu compounds

are fungicidal or bactericidal. It is known that the in vitro fungicidal activity is

largely dependent on its solubility in the spore exudate and in the fungal cell.)

The problem with popular copper fungicides is that, because they are largely

water insoluble, they are normally applied in relatively large volume aqueous

suspensions and, as such, are readily removed by rain. Frequent applications are

thus necessary at short intervals - an application process which is expensive and

environmentally imprudent. Therefore, the need exists for a highly water soluble Cu compound based

fungicide and bactericide that avoids the problems associated with phytotoxicity

experienced in the past with such compounds. A need also exists for such a water

soluble Cu compound based fungicide and bactericides that reduces the adverse Cu

load on the plant, thus reducing the non target impact to the environment. Further,

a need exists for such fungicidal and bactericidal compounds that permits use of

other heavy metals such as manganese, zinc, iron, copper and mixtures thereof, as

may be desired to for specific fungicidal or bactericidal properties.

SUMMARY OF THE INVENTION

The present invention address the problems outlined above, and provides an

improved anti-fungal and anti-bacterial compositions for plants that contains, as

active ingredients, fungicidally and bactericidally effective amounts of heavy metal

chelates in aqueous solution. According to the present invention, it has been

discovered that the application to the plant of the inventive composition substantially

eliminates fungus and bacteria disease, while at the same time, is substantially non-

phytotoxic.

Thus, an object of the present invention is to provide a fungicidal

composition for protection of plants against a fungal infection.

Another object of the invention is to provide such an antifungal protection

with a single product that upon application is not excessively phytotoxic.

Another object of the invention is to provide a method for treating plants and

to provide anti-fungal protection for plants against attack by fungus. Yet, further object of the invention is to provide an anti-fungal composition for treating plants

that is environmentally safe, inexpensive to use and has low mammalian toxicity.

Thus, an object of the present invention is to provide a bactericide

composition for protection of plants against a bacterial infection.

Another object of the invention is to provide a composition employing heavy

metal chelates that functions as both a fungicide and bactericide.

These and other objects of the invention are obtained by invention disclosed

below.

According to one aspect of the invention, anti-fungal compositions for the

protection of plants preferably contain, as an active material, a fungicidally effective

amount of a heavy metal chelate in mixture with an agriculturally acceptable carrier

such as water. According to another aspect of the invention, anti-bacterial

compositions for the protection of plants preferably contain, as an active material, a

bactericidally effective amount of a heavy metal chelate in mixture with an

agriculturally acceptable carrier, such as water.

According to another aspect of the invention, a single composition having

both fungicidal and bactericidal qualities is provided and contains fungicidally and

bactericidally effective amounts of heavy metal chelates in mixture with an

agriculturally acceptable carrier such as water.

The fungicidal and bactericidal compositions each preferably employ a heavy

metal chelate selected from the group consisting of Fe-EDDHA (ethylene-diamine di

(O-hydroxy phenylacetate)), Cu-EDDHA, Mn-EDDHA, and Zn-EDDHA and

mixtures thereof. According to another aspect of the invention, the amount of heavy metal

chelate is from about 0.01 to about 1.0 pounds Al per acre.

A DESCRIPTION OF THE DRAWINGS:

Fig 1 is the chemical structure for Fe EDTA (iron chelate of ethylene diamine

tetraacetic acid).

Fig 2 is the chemical structure for FE DTPA (iron chelate of diethylene-triamine

pentaacetic acid).

Fig 3 is the chemical structure for Fe EDDHA (iron chelate of ethylene

dihydroxyphenylacetic acid) or as listed in the U.S. Patent 2,921,847 ferrous and

ferric- APC A (iron chelates of ethylene bis(alpha imino-ortho-hydroxyphenylacetic

Acid)).

Fig 4 is the chemical structure for Fe pEDDHA (iron chelate of para ethylene

diamine dihydroxyphenylacetic acid).

Fig 5 is the chemical structure for Fe EDDHMA (iron chelate of ethylene diamine

dihydroxyphenylmethylacetic acid).

Fig 6 is the chemical structure for Cu EDDHA (copper chelate of ethylene diamine

dihydroxyphenylacetic acid).

A DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following examples set forth preferred concentrations and techniques for

formulation thereof, as well as methods of application and use in test results,

demonstrating the efficacy of the inventive concentration in protecting plants against

attack by fungi or bacteria, or both. It is to be understood, however, that these

Examples are presented by way of illustration only and nothing therein shall be taken as a limitation upon the overall scope of the invention. The specific

components tested in the Examples were prepared and applied as follows:

Cu-EDDHA was and can be prepared using the process disclosed in U.S.

Patent 2,921,847, the teachings of which are hereby incorporated herein by

reference. The '847 patent describes the process for the preparation of Fe-EDDHA,

which in the '847 patent is referred to as ferrous and ferric- APC A (iron chelates of

ethylene bis(alpha amino-ortho-hydroxyphenylacetic acid). To prepare Cu-

EDDHA, an appropriate Cu salt need merely be substituted for the iron salts

disclosed in the '847 patent. Likewise, other heavy metal chelates disclosed herein

may be prepared by substituting the desired heavy metal for Cu in the process

disclosed in the '847 patent. The chemical structure for Cu-EDDHA is illistrated in

Fig. 6. The chemical structures for other common heavy metal chelates are

illistrated in the following figures: Fig. 1 Fe-EDTA; Fig. 2, Fe-DTPA; Fig. 3, Fe-

EDDHA; Fig. 4, Fe-pEDDHA; and Fig 5, Fe-EDDHMA.

METHOD OF APPLICATION

The preferable method of application is foliar, either by ground or aerial

equipment, but is not limited to that method alone. Injection or soil applications,

for example, can also be applications depending upon specific crops and pathogens.

The inventive compositions have utility on fruit crops, and agronomic crops,

ornamentals, trees, grasses, vegetables, grains, and flori cultural crops, as well as,

some aquatic crops including rice. The fungicidal and bactericidal properties of the compounds according to the

invention are various, but are particularly interesting in the case described in the

following examples: As used in the Examples, "Ave. % infection" means percent of leaves that

exhibit fungus lesions. EXAMPLE 1

Cu-EDDHA and four commercially accepted fungicidal compositions were

applied to Valencia orange on sour orange rootstock. Applications were in 100

gallons of solution (in the concentrations indicated) per acre in mid-summer to

single-tree plots replicated six times in a randomized complete block ("RCB")

design. Seven months later the percentages of citrus greasy spot infection on five branch terminals from each tree were recorded and averaged.

CITRUS GREASY SPOT TEST

CAUKINS GROVES, INDIANTOWN, FLORIDA

RATE/100 * AVE %

TREATMENT GAL. INFECTION 2/10/88

1) FCC-455 Spray Oil (Fla. Citrus

Commission) 1 % 30.0

2) Difenconazole 50 g ai 1.56

3) Difenconazole 100 g ai 1.0

4) Cu-EDDHA 3.2% 0.2 lb ai 2.5

5) KOCIDE 101 4 lbs. 23

6) Untreated — 35

APPL. Single tree plots x 6 Reps.

* Aug. 5 terminals/tree Difenconazole: l-[2-[4-(4-chlorophenoxy)-2-chlorophenyl-(4-methyl-l, 3-dioxolan-

2-yl)-methyl]]-lH-l,2,4-triazole (available from Ciba-Geigy, Greenbough, N.C.)

Cu-EDDHA: sodium cupric ethylene-diamine di (o-hydroxyphenylacetate).

KOCIDE 101 available from Griffin Corp., Valdosta, Ga.

* % infection of citrus greasy spot (Mycosphaerella citri

EXAMPLE 2 FUNGICIDE

Cu-EDDHA, TILT (propiconzaole-Ciba-Geigy) and difenconozole were

applied in 100 gpa to single tree plots of "Valencia" oranges replicated five times in

a RCB design in mid- July.

Twenty mature leaves (from the spring flush) per replicate were harvested

approximately 4 months later and placed under greenhouse conditions and

alternately wetted and dried to simulate natural defoliation and weathering.

These conditions in turn cause the fungus to sporulate by the formation of

perithecia (spore production body of fungus) which were counted as a means of

measuring the fungicidal activity of the treatments. These data are presented below.

CITRUS GREASY SPOT

SCN NURSERY, DUNDEE, FLORIDA

RATE/100

TREATMENT GAL. #PERITHECIA

1) Cu-EDDHA 3.2% 0.2 lb ai 3.24 b

2) Cu-EDDHA 3.2% 0.4 lb ai 5.93 ab

3) TILT 3.6 EC 6 oz. Prod. 6.62 ab

4) Difenconzaole 100 g ai 5.32 ab

5) Difenconazole 200 g ai 11.57 ab

6) CONTROL inoculated 7.97 ab

7) CONTROL not 6.42 ab inoculated Function: ANOVA— 1

Date case no. 1 to 42

Without selection

One way ANOVA grouped over variable 1

TREATMENT NUMBER

with values from 1 to 7

Variable 3

NUMBER OF PERITHECIA PER 5MM FIELD AT 2.5 X -MEAN OF THREE

OBSERVATIONS

ANALYSIS OF VARIANCE TABLE

Degrees of Sum of Error Mean

Freedom Squares Square F-value Prob.

Between 6 226.6508 37.78 1.33 .270

Within 34 965.0170 28.38

Total 40 1191.6678

EXAMPLE 3 FUNGICIDE

Cu-EDDHA, Kocide (cupric hydroxide) and difenconazole were applied to

single tree plots of "Hamlin" oranges in 100 gpa (in concentration indicated) in a

RCB design replicated 4 times. Applications were made in May, June and May and

June. Ten fruit/replicate were sampled in July and percent infection of Melanose

(Diaporthe citri) was determined. See data presented below. CITRUS MELANOSE CONTROL

R.E. KEENE FRUIT COMPANY

RATE LBAI/100 % INFECTION

TREATMENT GAL. TIMING (FRUIT)

Cu-EDDHA 3.2% 0.2 May 9

Cu-EDDHA 3.2% 0.4 May 13

Cu-EDDHA 3.2% 0.8 May 21

Cu-EDDHA 3.2% 0.2 May-June 11

Cu-EDDHA 3.2% 0.4 May-June 15

Cu-EDDHA 3.2% 0.8 May-June 29

Cu-EDDHA 3.2% 0.2 June 14

KOCIDE 4.0 May 12

KOCIDE 0.4 May-June 10

DIFENCONAZOLE 0.5 June 4

Untreated — — 38

4 REPS SINGLE TREE PLOTS.

PENETRATOR (surfactant - non-ionic)@ 4 oz. ALL TREATMENTS

EXAMPLE 4 FUNGICIDE

GRAPEFRUIT (Citrus paradisi 'Marsh')

Greasy spot; Mycosphaerella citri

GREASY SPOT CONTROL ON LEAVES, 1986-87: Spray treatments

were applied dilute (applied to point of run off) by handgun in July to 10-ft-high

trees at a rate equivalent to 700 gal/acre. Treatments were replicated on 8 single¬

tree plots in a RCB design. Groups of 15 shoots on each of the east/west and east

side of each tree were tagged and the initial number of leaves was recorded. In

February, remaining leaves were counted and examined for greasy spot. All treatments except Difolatan (fungicide) reduced greasy spot-induced

defoliation and the percentage number of remaining leaves with greasy spot

symptoms. There were no significant differences in effectiveness between Tribasic

copper sulfate, spray oil, Spotless, Tilt, and Cu-EDDHA. There was too little

greasy spot rind blotch in this test to provide information on the relative efficacy of

treatments for preventing fruit infection.

% remaining leaves

Treatment and rate/100 gal defoliation with greasy spot

Tribasic copper sulfate (53 % Cu) 0.75 lb 1.9 a 20.1 a

Sunspray 7E oil 1 gal 3.1 a 27.0 a

Difolatan 80 Sprills 1.25 lb 8.9 b 49.8 b

Spotless 25W 0.8 lb 1.3 a 22.6 a

Tilt 3.6EC 8 fl oz. 1.5 a 15.9 a

Cu-EDDHA (3.2% Cu) 1.5 gal 0.8 a 12.0 a

Untreated 9.7 b 48.5 b

EXAMPLE 5 FUNGICIDE

Cu-EDDHA, TILT (propinconazole), difenconozole and MERTECT (Merck

Chem. , N.J.) (thiabendazole) were applied in 100 gpa to 2-year-old laurel oaks

(Quercus hemispherica) in 2x2 gal. pots in a RCB design replicated 4 times.

Applications were made in July approximately 3 weeks apart and rated in August a

month later. See data below.

OAK LEAF BLISTER (Taphrina caerulescens) CONTROL

TRAILRIDGE NURSERY, KEYSTONE HEIGHTS, FLORIDA

RATE/PROD ^DISEASE

TREATMENT 100 GAL, INDEX

1) Tilt 3.6 emulsifiable 8 oz 1.5

2) Difenconazole 3.6 2 oz 2.25 emulsifiable

3) Cu-EDDHA 3.2 8 oz 2.8

4) MERTECT 8 oz 1.5

5) Untreated — 4.25

ise Index: Rated 8/26/86. 1 = no disease

2 = light

3 = moderate

4 = heavy

5 = dead foliage

2 x 2 gal trees/exp. unit x 4 Reps in a RCB design

EXAMPLE 6 BACTERICIDE

Cu-EDDHA and Kocide (cupric hydroxide) were applied as foliar spray in

May to Hibiscus sinensis cuttings (100/replicate) x 4 replicates in a RCB design.

Treatments were allowed to dry for one hour and then placed in a commercial

propagation bed under intermittent mist and rated for bacterial (Erwinia

chrysanthemi) infection one week later. Data presented below.

*ERWINIA CONTROL ON HIBISCUS

NELSONS NURSERY, APOPKA, FLORIDA

RATE/CU AVG. %

TREATMENT 100 GAL. INFECTION

1) Cu-EDDHA 3.2% 0.2 lb. ai 6

2) Cu-EDDHA 3.2% 0.4 lb. ai 8

3) KOCIDE 101 2 lbs. ai 25

4) Untreated — 100

100 Cuttings/REP X 4 *ERWINIA chrysanthemi

EXAMPLE 7 BACTERICIDE

A follow-up experiment to EXAMPLE 6 was conducted on rooted cuttings

which were dipped as they were removed from the propagation bed and foliarly

sprayed 7 days later after being potted. Cu-EDDHA and Kocide were applied at the

rates specified below in a RCB design utilizing 100 plants/replicate x 4 reps. Potted

cuttings had not received any previous bactericide treatments prior to potting.

ERWINIA CONTROL ON HIBISCUS

NELSONS NURSERY-APOPKA, FLORIDA

RATE/LBAI AVE. %

TREATMENT 100 GAL. INFECTION

Cu-EDDHA 3.2% 0.2 19

Cu-EDDHA 3.2% 0.8 32

KOCIDE 2.0 22

APPLIC. DATES: 7/19 DIP, 7/26/85 SPRAY

100 PLANTS/REP. X 4

EXAMPLE 8 BACTERICIDE

Control of Bacterial Spot on Pepper Plants

With Stage II Bactericides Procedure— Early Cal Wonder variety pepper plants were treated at weekly intervals

with the following bactericides (g ai/liter): copper + mancozeb (2 + 1), Cu-

EDDHA (0.1), CGA (Ciba-Giegy of America - Bactericides)- 115944, CGA-

151731, CGA-157566, and CGA-164058 (each at 0.25 and 0.5), CGA-143268

(1.0). Treatments were applied weekly in 1000 1/ha for a total of eight

applications. The crop was artificially inoculated after the first and third

applications. Disease severity was evaluated after the fourth and eight applications.

Phytotoxicity was rated after the eight application and yields were taken continually

during the test.

Results— Disease pressure was moderate and uniform. After four applications, the

best treatments were CGA-115944, CGA-151731 , and CGA-164058. CGA-157566

was less effective than the three previously mentioned compounds but more

effective than CGA-143268 which was equal to copper plus mancozeb and Cu-

EDDHA in activity. The ranking of compounds changed when treatments were

rated 12 days after the last application. Copper plus mancozeb control has

completely broken down, which was expected because disease conditions were

severe in the final half of the test and copper should be applied on a five-day

schedule under these conditions. Cu-EDDHA at only 0.05X the rate of Kocide 101

(on a metallic copper basis) was exhibiting some control and was equal to CGA-

143268, CGA-157566, and CGA-164058. The best bactericide at the second rating

were CGA-115944 and CGA-151731. The phytotoxicity of all treatments was

assessed after eight applications had been made. The only bactericides which were

phytotoxic were CGA-115944 and CGA-164058. CGA-164058 was safer than CGA115944 which was marginally unacceptable at 0.5 g ai/1. CGA-143268 and

CGA-164058 increased yields dramatically. Yields were depressed by CGA-

0115944, CGA-151731, and CGA-157566. Cu-EDDHA had no effect on yield and

copper + mancozeb increased yields moderately. In summary, several compounds

showed excellent activity, but none had sufficient crop safety.

EXAMPLE 9 BACTERICIDE

Cu-EDDHA at 0.2 and 0.4 lbs. ai/100 gal. and Kocide 101 at 7.4 lbs. ai/A

were applied as foliar applications to croton (Codiaeum variegatum) previously

inoculated with Xanthomonas campestris a day earlier. Treatments were assigned in

a RCB design and replicated 10 times with single pots. Treatments were applied 3

times on a weekly schedule and evaluated at 7 and 14 days following the last

application. See data below.

Test 1 Codiaeum Inoculated with Xanthomonas

Number of leaves with symptoms

RATE/100 AVE. %

TREATMENT GAL. a.i. INFECTION

Water noninoculated 0 a

Water inoculated 2.6 c

Cu-EDDHA 3.2% 26 ml (.2 lb.) .6 ab

Cu-EDDHA 3.2% 52 ml (.4 lb.) 1.0 b

Kocide 101 6.8 ml. (7.4 lb.) .9 ab

ANOVA table Source Sum of squares df Mean square F Value

Treatment 37.28 4 9.319 9.177 significant at 1 % level

Error 45.7 45 1.016 Total 82.98 49

All of the copper treatments provided some control of Xanthomonas leaf spot of

Codiaeum, when compared to the inoculated control. The lower rate of Cu-

EDDHA and the Kocide 101 gave control equal to the noninoculated control

treatment.

CARROT/ ALTERNARIA FUNGICIDE TRIAL

AVG % INFECTION

RATE/100

TREATMENT GAL. 04/05/96 04/23/96

1) K-PHOS 1 % 6.9 8.2

2) PHOS-MIGHT 1 % 18.7 28.8

3) K-PHOS 0.5% 8.9 10.7 + + PHOS-MIGHT 0.5 %

4) Cu-EDDHA 0.2 lb ai 8.8 11.6

5) Fe-EDDHA 0.2 lb ai 12.7 12.9

6) Untreated 23.0 34.8

*EDDHA (ethylene-diamine di (O-hydroxy phenylacetate)

PLOT SIZE: Single Row X 25 ft. X 4 reps in a RCB design.

Application dates: 2/2, 9,15,22,3/8,14,22, and 28. Rated 4/5 and 4/23/96

NOTE: Second rating was 25 days after last fungicide application. Plots were

inoculated with Alternaria dauci

Sanford, FL

K-PHOS (Commercially available and is sold under trademark "K-Phos" by Foliar

Nutrients, Inc. , Cairo, GA 31724) (K₂HPO₄, 0-18-20) PHOS MIGHT (Commercially available and is sold under trademark "Phos Might"

by Foliar Nutrients, Inc., Cairo, GA 31724) (K₂HPO₃, 0-22-20)

EXAMPLE 15 - FUNGICIDE

CRAPE MYRTLE POWDERY MILDEW CONTROL

AVG % INFECTION TREATMENT RATE/100GAL. FL GL FOLIAGE 1) K-PHOS 1 % 12.0 22.50 2) Cu-EDDHA 0.2 lb ai 11.20 16.4 3) Fe-EDDHA 0.2 lb ai 6.4 0 4) K-PHOS 1 % 4.2 0 + Cu-EDDHA 0.2 lb ai 100 100

FL.GL. =unopended flower clusters (2/trtm X 4 reps)

Foliage (2 terminals - 10 leaves X 4 reps in RCB design).

Crape Myrtle (Lager stromia indica)

Powdery Mildrew (Erysiphe lagerstroemiae)

App. dates: 5/23, 30th and 6/6. Rated: 6/9

K-PHOS - (K₂HPO₄, 0-18-20) ("K-Phos" is a trademark of Foliar Nutrients, Inc. ,

Cairo, Ga.)

The above Examples demonstrate that the inventive compositions are useful in

protecting plants against attack by fungus with the application of the inventive

solution.

It will be further appreciated that foliar application of the inventive

compositions will be effective as a common agricultural practice to control bacterial

infections in plants. As used herein, the term "heavy metal chelate" is intended to refer to an

organic coordination "complexing" compound in which a metal ion is bound to

atoms of non-metals, e.g., nitrogen, carbon or oxygen, to form a hetrocylic ring

having coordinate covalent bounds. The non-metal atoms may be attached to the

metal ions by from one to six linkages and, thus, are called uni-, bi-, tri- dentate,

etc. , meaning 1-, 2-, or 3-tooth. Heavy metals, such as cobalt, copper, iron, nickel,

zinc, magnesium and platinum are metal ions that are commonly involved in chelate

structures. Examples of heavy metal chelate structures include:

Fe-HEEDTA (hydroxy ethylenediamine triacetic acid), Fe-EDTA

(ethylenediamine tetra acetic acid), Fe-DTPA (diethylene triaminepenta acetic acid),

Fe-EDDHA (ethylene dihydroxyphenylacetic acid), ethylene bis dithiocarbamates of

Mn- and Zn-, Cu-EDDHA, Mn- and Zn-EDDHA.

As used herein, unacceptably high levels of phytotoxicity is intended to mean

foliar burn, defoliation and stem die-back, or necrosis, plant stunting or death.

Phytotoxicity is also rated on an international scale of 0-10 where 0 is equal to no

phytotoxicity and 10 is complete death of the plant.

Heavy metal chelates disclosed herein are possess water solubility acceptable

for use in the inventive fungicide and bactericide.

For example, the solubility of sequestrene 138 Fe Iron Chelate in pounds per

100 gallons of water, at various temperatures (solubility weight/100 gals. H_jO) is

shown in Table 1 below: Temperature (^°C) Lbs.

0 69

10 70

20 75

30 81

40 84

50 88

Commercially produced Sequestrene 138 Fe contains 6% Iron as metallic, or 8.5%

iron as Fe₂O₃. The commercial product has a moisture content of not more than

10% .

Without being limited to this theory, it is believed that heavy metal chelation

generally increases water solubility of the heavy metal ion and the availability in

certain soil conditions of the metal ion where calcareous and high pH situations

would otherwise prevent metal ions from being available to the plant as a fungicide.

It is believed that certain heavy chelates (usually in the form of Mn, Zn, and

Fe) may be applied foriarly at much reduced rates when compared to inorganic salts

intended for fungicidal and bactericidal use.

Ranking of Fe chelates used in foliar applications are as follows: Fe-HEEDTA

- most phytotoxic; Fe-EDTA ~ intermediate phytotoxic, Fe-DTPA - less

phytotoxic, and Fe-EDDHA - least phytotoxic. Such rankings do not necessarily

apply when the chelate is EBDC fungicides in the Mn, Zn form.

It will be appreciated by those skilled in the art that beneficial effects

demonstrated in the Examples by the use of Cu-EDDHA will also be obtained when the Mn, Zn and Fe forms EDDHA and other forms of heavy metal chelates are

employed.

Claims

CLAIMSWhat is claimed is:

1. A fungicidal composition for controlling fungus disease in plants

comprising:

a fungicidally effective amount of a heavy metal chelate in aqueous solution.

2. The composition according to Claim 1, wherein the heavy metal is

selected from the group consisting of manganese, zinc, iron, and copper, and

mixture thereof.

3. The composition according to Claim 1 , wherein the amount of said

heavy metal chelate is present in aqueous solution from about 0.01 to about 1.0

pounds AI per acre.

4. A method of controlling fungus disease in plants comprising:

applying to the plant in fungicidally effective amounts a heavy metal chelate in

aqueous solution.

5. A method according to Claim 4, wherein said solution comprises an

aqueous solution, wherein said heavy metal chelate is present in solution from about

0.01 to about 1.0 pounds AI per acre.

6. A bacterial composition for controlling bacteria disease in plants comprising:

a bacterially effective amount of a heavy metal chelate in aqueous solution.

7. The composition according to Claim 6, wherein the heavy metal is

selected from the group consisting of manganese, zinc, iron, and copper.

8. The composition according to Claim 6, wherein the amount of said heavy metal chelate is present in aqueous solution from about 0.01 to about 1.0 pounds AI per acre.

9. A method of controlling bacteria disease in plants comprising:

applying to the plant in bacterially effective amounts a heavy metal chelate in aqueous solution.

10. A method according to Claim 9, wherein said solution comprises an

0.01 to about 1.0 pounds AI per acre.

11. A fungicidal and bactericidal composition for controlling fungus and

bacteria disease in plants comprising:

a fungicidally and bactericidally effective amount of a heavy metal chelate in

aqueous solution.

12. The composition according to Claim 11, wherein the heavy metal is

selected from the group consisting of manganese, zinc, iron, and copper, and mixture thereof.

13. The composition according to Claim 11, wherein the amount of said

heavy metal chelate is present in aqueous solution from about 0.01 to about 1.0

pounds AI per acre.

14. A method of controlling fungus and bacterial disease in plants comprising:

applying to the plant in fungicidally and bactericidally effective amounts a

heavy metal chelate in aqueous solution.

15. A method according to Claim 14, wherein said solution comprises an

0.01 to about 1.0 pounds AI per acre.