AU743922B2 - Fungicidal and bactericidal compositions for plants containing compounds in the form of heavy metal chelates - Google Patents

Description

WO 98/58546 PCT/US98/12264 1 TITLE 2 FUNGICIDAL AND BACTERICIDAL COMPOSITIONS FOR PLANTS 3 CONTAINING COMPOUNDS IN THE FORM OF HEAVY METAL CHELATES 4 6 7 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 12 compositions and methods of use of the invention including fungicidally and 13. bacterially effective amounts of copper compounds in form of heavy metal chelates, 14 and preferably in the form of Cu-EDDHA, cupric ethylene diamine dio- 1 hydroxyphenylacetate in aqueous solution).

6. BACKGROUND OF THE INVENTION 17 Fungicides, as well as bactericides, are chemical agents used to protect 18 agricultural crops from those pathogens which, if left uncontrolled, would result in 19 unacceptable economic losses.

Copper compounds that are active as fungicides and bactericides have been '21 in agricultural use since the advent of Bordeaux in the grape vineyards of France in 22 the early 1800's. Many different formulations of fungicides employing copper 23 compounds, such as wettable powders, water based flowables and dry flowables, are 24 commonly used today in modern agricultural applications.

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WO 98/58546 PCT/US98/12264 1 Such copper compounds, for the most part, have been inorganic in form 2 when applied to agricultural uses. Organic forms of the copper compounds have 3 been found to be generally phytotoxic, especially in foliar applications. (Certain 4 organic copper compounds, however, have some utility as fungicides CUTRINE Cu salt of triethanole amine) is quite effective as an aquatic algaecide.) 6 Modern day agricultural use of inorganic copper compounds as fungicides 7 employ varying forms of copper compounds having relatively low water solubility, 8 including for example, cupric hydroxide, tri basic copper sulfate and tank mix 9 combinations (with heavy metal ethylene bis dithiocarbamate fungicides to enhance the bactericidal activity against certain important agricultural bacteria such as 11 Xanthomonas, Pseudomonas, and Erwinia).

12 Water soluble copper compounds such as CuSO 4 though effective to inhibit 13 germination of fungus spores, cannot be used in foliar applications to agricultural 14 crops because the cupric ion is extremely phytotoxic. Therefore, relatively insoluble forms of inorganic copper compounds, such as cupric hydroxide, have 16 been found to be more effective fungicides. (Not all water insoluble Cu compounds 17 are fungicidal or bactericidal. It is known that the in vitro fungicidal activity is 18 largely dependent on its solubility in the spore exudate and in the fungal cell.) 19 The problem with popular copper fungicides is that, because they are largely water insoluble, they are normally applied in relatively large volume aqueous 21 suspensions and, as such, are readily removed by rain. Frequent applications are 22 thus necessary at short intervals an application process which is expensive and 23 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 In one aspect, the invention provides a composition when used for controlling fungal and/or bacterial disease in plants comprising a fungicidally and/or bactericidally effective amount of a heavy metal chelate in an aqueous solution, wherein said effective amount of the heavy metal chelate has low or no phytotoxicity to plants, wherein the S heavy metal is selected from the group consisting of zinc, manganese, copper, and combinations thereof, and wherein the chelate is selected from the group consisting of EDDHA, pEDDHA, EDDHMA and combinations thereof.

In one embodiment the heavy metal chelate is present in an aqueous solution in an amount equal to from about 0.01 to about 1.0 pounds of the heavy metal chelate per acre.

In another embodiment, the heavy metal chelate is selected from the group consisting of Cu-EDDHA, Cu-PEDDHA, Cu-EDDHMA, and combinations thereof.

In another aspect there is provided a method for controlling fungal and/or bacterial disease in plants comprising applying to a plant a composition described above.

SR In one embodiment the heavy metal chelate is present it the aqueous solution in an amount equal to from about L I 0.01 to about 1.0 pounds of the heavy metal chelate per acre.

In another embodiment the heavy metal chelate is selected from the group consisting of Cu-EDDHA, Cu-PEDDHA, Cu-EDDHMA, and combinations thereof.

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.

At least some of these and other objects of the invention are obtained by invention described herein.

WO 98/58546 PCT/US98/12264 1 2 3 A DESCRIPTION OF THE DRAWINGS: 4 Fig 1 is the chemical structure for Fe EDTA (iron chelate of ethylene diamine tetraacetic acid).

6 Fig 2 is the chemical structure for FE DTPA (iron chelate of diethylene-triamine 7 pentaacetic acid).

S 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-APCA (iron chelates of ethylene bis(alpha imino-ortho-hydroxyphenylacetic :11 Acid)).

12 Fig 4 is the chemical structure for Fe pEDDHA (iron chelate of para ethylene .13. diamine dihydroxyphenylacetic acid).

Fig 5 is the chemical structure for Fe EDDHMA (iron chelate of ethylene diamine dihydroxyphenylmethylacetic acid).

0 .*ti Fig 6 is the chemical structure for Cu EDDHA (copper chelate of ethylene diamine 17 dihydroxyphenylacetic acid).

18 A DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 19 The following examples set forth preferred concentrations and techniques for formulation thereof, as well as methods of application and use in test results, .21 demonstrating the efficacy of the inventive concentration in protecting plants against -22 attack by fungi or bacteria, or both. It is to be understood, however, that these 23 Examples are presented by way of illustration only and nothing therein shall be WO 98/58546 PCT/US98/12264 1 taken as a limitation upon the overall scope of the invention. The specific 2 components tested in the Examples were prepared and applied as follows: 3 Cu-EDDHA was and can be prepared using the process disclosed in U.S.

4 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, 6 which in the '847 patent is referred to as ferrous and ferric-APCA (iron chelates of 7 ethylene bis(alpha amino-ortho-hydroxyphenylacetic acid). To prepare Cu- 8 EDDHA, an appropriate Cu salt need merely be substituted for the iron salts 9 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 11 disclosed in the '847 patent. The chemical structure for Cu-EDDHA is illistrated in 12 Fig. 6. The chemical structures for other common heavy metal chelates are 13 illistrated in the following figures: Fig. 1 Fe-EDTA; Fig. 2, Fe-DTPA; Fig. 3, Fe- 14 EDDHA; Fig. 4, Fe-pEDDHA; and Fig 5, Fe-EDDHMA.

METHOD OF APPLICATION 16 The preferable method of application is foliar, either by ground or aerial 17 equipment, but is not limited to that method alone. Injection or soil applications, 18 for example, can also be applications depending upon specific crops and pathogens.

19 The inventive compositions have utility on fruit crops, and agronomic crops, ornamentals, trees, grasses, vegetables, grains, and flori cultural crops, as well as, 21 some aquatic crops including rice.

WO 98/58546 PCT/US98/12264 1 The fungicidal and bactericidal properties of the compounds according to the 2 invention are various, but are particularly interesting in the case described in the 3 following examples: 4 As used in the Examples, "Ave. infection" means percent of leaves that exhibit fungus lesions.

6 EXAMPLE 1 7 Cu-EDDHA and four commercially accepted fungicidal compositions were 8 applied to Valencia orange on sour orange rootstock. Applications were in 100 9 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") 11 design. Seven months later the percentages of citrus greasy spot infection on five 12 branch terminals from each tree were recorded and averaged.

13 CITRUS GREASY SPOT TEST 14 CAUKINS GROVES, INDIANTOWN, FLORIDA RATE/100 AVE TREATMENT GAL. INFECTION 2/10/88 1) FCC-455 Spray Oil (Fla. Citrus Commission) 1% 30.0 16 2) Difenconazole 50 g ai 1.56 17 3) Difenconazole 100 g ai 18 4) Cu-EDDHA 3.2% 0.2 lb ai 19 5) KOCIDE 101 4 lbs. 23 6) Untreated 21 APPL. Single tree plots x 6 Reps.

22 Aug. 5 terminals/tree WO 98/58546 PCT/US98/12264 1 Difenconazole: 1-[2-[4-(4-chlorophenoxy)-2-chlorophenyl-(4-methyl-1, 3-dioxolan- 2 2-yl)-methyl]]-1H-1,2,4-triazole (available from Ciba-Geigy, Greenbough, N.C.) 3 Cu-EDDHA: sodium cupric ethylene-diamine di (o-hydroxyphenylacetate).

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

infection of citrus greasy spot (Mycosphaerella citri) 6 EXAMPLE 2 FUNGICIDE 7 Cu-EDDHA, TILT (propiconzaole-Ciba-Geigy) and difenconozole were 8 applied in 100 gpa to single tree plots of "Valencia" oranges replicated five times in 9 a RCB design in mid-July.

Twenty mature leaves (from the spring flush) per replicate were harvested 11 approximately 4 months later and placed under greenhouse conditions and 12 alternately wetted and dried to simulate natural defoliation and weathering.

13 These conditions in turn cause the fungus to sporulate by the formation of 14 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.

16 CITRUS GREASY SPOT 17 SCN NURSERY, DUNDEE, FLORIDA RATE/100 TREATMENT GAL. #PERITHECIA 18 1) Cu-EDDHA 3.2% 0.2 lb ai 3.24 b 19 2) Cu-EDDHA 3.2% 0.4 lb ai 5.93 ab 3) TILT 3.6 EC 6 oz. Prod. 6.62 ab 21 4) Difenconzaole 100 g ai 5.32 ab 22 5) Difenconazole 200 g ai 11.57 ab 23 6) CONTROL inoculated 7.97 ab 24 7) CONTROL not 6.42 ab inoculated t 7 WO 98/58546 PCT/US98/12264 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.

WO 98/58546 PCT/US98/12264

TREATMENT

Cu-EDDHA 3.2% Cu-EDDHA 3.2% Cu-EDDHA 3.2% Cu-EDDHA 3.2% Cu-EDDHA 3.2% Cu-EDDHA 3.2% Cu-EDDHA 3.2%

KOCIDE

KOCIDE

DIFENCONAZOLE

Untreated CITRUS MELANOSE CONTROL R.E. KEENE FRUIT COMPANY RATE LBAI/100 GAL. TIMING 0.2 May 0.4 May 0.8 May 0.2 May-June 0.4 May-June 0.8 May-June 0.2 June 4.0 May 0.4 May-June 0.5 June

INFECTION

(FRUIT)

9 13 21 11 29 14 12 4 38 16 17 18 19 21 22 23 24 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 trees at a rate equivalent to 700 gal/acre. Treatments were replicated on 8 singletree 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.

WO 98/58546 PCT/US98/12264 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 Ib 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 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., (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.

WO 98/58546 PCT/US98/12264 i

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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 Difenconazole 3.6 2 oz 2.25 emulsifiable Cu-EDDHA 3.2 8 oz 2.8 1) MERTECT 8 oz Untreated 4.25 Disease Index: Rated 8/26/86. 1 no disease 2 light 3 moderate 4 heavy 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.

WO 98/58546 PCT/US98/12264 1 *ERWINIA CONTROL ON HIBISCUS 2 NELSONS NURSERY, APOPKA, FLORIDA RATE/CU AVG. TREATMENT 100 GAL. INFECTION 3 1) Cu-EDDHA 3.2% 0.2 lb. ai 6 4 2) Cu-EDDHA 3.2% 0.4 lb. ai 8 3) KOCIDE 101 2 lbs. ai 6 4) Untreated -100 7 100 Cuttings/REP X 4 *ERWINIA chrysanthemi 8 EXAMPLE 7 BACTERICIDE 9 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 11 sprayed 7 days later after being potted. Cu-EDDHA and Kocide were applied at the 12 rates specified below in a RCB design utilizing 100 plants/replicate x 4 reps. Potted 13 cuttings had not received any previous bactericide treatments prior to potting.

14 ERWINIA CONTROL ON HIBISCUS NELSONS NURSERY-APOPKA, FLORIDA RATE/LBAI AVE. 16 TREATMENT 100 GAL. INFECTION 17 Cu-EDDHA 3.2% 0.2 19 18 Cu-EDDHA 3.2% 0.8 32 19 KOCIDE 2.0 22 APPLIC. DATES: 7/19 DIP, 7/26/85 SPRAY 21 100 PLANTS/REP. X 4 22 EXAMPLE 8 BACTERICIDE 23 Control of Bacterial Spot on Pepper Plants 24 With Stage II Bactericides WO 98/58546 PCT/US98/12264 1 Procedure-Early Cal Wonder variety pepper plants were treated at weekly intervals 2 with the following bactericides (g ai/liter): copper mancozeb (2 Cu- 3 EDDHA CGA (Ciba-Giegy of America Bactericides)-115944,

CGA-

4 151731, CGA-157566, and CGA-164058 (each at 0.25 and CGA-143268 Treatments were applied weekly in 1000 1/ha for a total of eight 6 applications. The crop was artificially inoculated after the first and third 7 applications. Disease severity was evaluated after the fourth and eight applications.

8 Phytotoxicity was rated after the eight application and yields were taken continually 9 during the test.

Results-Disease pressure was moderate and uniform. After four applications, the 11 best treatments were CGA-115944, CGA-151731, and CGA-164058. CGA-157566 12 was less effective than the three previously mentioned compounds but more 13 effective than CGA-143268 which was equal to copper plus mancozeb and Cu- 14 EDDHA in activity. The ranking of compounds changed when treatments were rated 12 days after the last application. Copper plus mancozeb control has 16 completely broken down, which was expected because disease conditions were 17 severe in the final half of the test and copper should be applied on a five-day 18 schedule under these conditions. Cu-EDDHA at only 0.05X the rate of Kocide 101 19 (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 21 were CGA-115944 and CGA-151731. The phytotoxicity of all treatments was 22 assessed after eight applications had been made. The only bactericides which were 23 phytotoxic were CGA-115944 and CGA-164058. CGA-164058 was safer than ~L i I WO 98/58546 PCT/US98/12264 1 CGA115944 which was marginally unacceptable at 0.5 g ai/1. CGA-143268 and 2 CGA-164058 increased yields dramatically. Yields were depressed by CGA- 3 0115944, CGA-151731, and CGA-157566. Cu-EDDHA had no effect on yield and 4 copper mancozeb increased yields moderately. In summary, several compounds showed excellent activity, but none had sufficient crop safety.

6 EXAMPLE 9 BACTERICIDE 7 Cu-EDDHA at 0.2 and 0.4 lbs. ai/100 gal. and Kocide 101 at 7.4 lbs. ai/A 8 were applied as foliar applications to croton (Codiaeum variegatum) previously 9 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 11 times on a weekly schedule and evaluated at 7 and 14 days following the last 12 application. See data below.

13 Test 1 Codiaeum Inoculated with Xanthomonas 14 Number of leaves with symptoms RATE/100 AVE. TREATMENT GAL. a.i. INFECTION 16 Water noninoculated 0 a 17 Water inoculated 2.6 c 18 Cu-EDDHA 3.2% 26 ml lb.) .6 ab 19 Cu-EDDHA 3.2% 52 ml lb.) 1.0 b Kocide 101 6.8 ml. (7.4 lb.) .9 ab 21 ANOVA table iijL.._ ~~1LI~ WO 98/58546 PCT/US98/12264 Source Treatment Sum of squares 37.28 Mean square F Value 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 4) Cu-EDDHA 0.2 lb ai 8.8 11.6 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) (K 2

HPO

4 0-18-20) i i WO 98/58546 PCT/US98/12264 1 2 3 4 6 7 8 *o

P.:

31...

I

:14'.

to* o 19 21 22 23 .24 PHOS MIGHT (Commercially available and is sold under trademark "Phos Might" by Foliar Nutrients, Inc., Cairo, GA 31724) (K2HP0 3 0-22-20) -EXAMPLE 10 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 (Lagerstromia indica) Powdery Mildrew (Erysiphe lagerstroemiae) App. dates: 5/23, 30th and 6/6. Rated: 6/9 K-PHOS (K2HPO 4 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.

WO 98/58546 PCT/US98/12264 1 As used herein, the term "heavy metal chelate" is intended to refer to an 2 organic coordination "complexing" compound in which a metal ion is bound to 3 atoms of non-metals, nitrogen, carbon or oxygen, to form a hetrocylic ring 4 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, 6 etc., meaning or 3-tooth. Heavy metals, such as cobalt, copper, iron, nickel, 7 zinc, magnesium and platinum are metal ions that are commonly involved in chelate 8 structures. Examples of heavy metal chelate structures include: 9 Fe-HEEDTA (hydroxy ethylenediamine triacetic acid), Fe-EDTA (ethylenediamine tetra acetic acid), Fe-DTPA (diethylene triaminepenta acetic acid), 11 Fe-EDDHA (ethylene dihydroxyphenylacetic acid), ethylene bis dithiocarbamates of 12 Mn- and Zn-, Cu-EDDHA, Mn- and Zn-EDDHA.

13 As used herein, unacceptably high levels of phytotoxicity is intended to mean 14 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 16 phytotoxicity and 10 is complete death of the plant.

17 Heavy metal chelates disclosed herein are possess water solubility acceptable 18 for use in the inventive fungicide and bactericide.

19 For example, the solubility of sequestrene 138 Fe Iron Chelate in pounds per 100 gallons of water, at various temperatures (solubility weight/100 gals. HO 2 is 21 shown in Table 1 below: WO 98/58546 PCT/US98/12264 1 Temperature Lbs.

2 0 69 3 10 4 20 30 81 6 40 84 7 50 88 8 Commercially produced Sequestrene 138 Fe contains 6% Iron as metallic, or 9 iron as Fe 2

O

3 The commercial product has a moisture content of not more than 11 Without being limited to this theory, it is believed that heavy metal chelation 12 generally increases water solubility of the heavy metal ion and the availability in 13 certain soil conditions of the metal ion where calcareous and high pH situations 14 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 16 Fe) may be applied foriarly at much reduced rates when compared to inorganic salts 17 intended for fungicidal and bactericidal use.

18 Ranking of Fe chelates used in foliar applications are as follows: Fe-HEEDTA 19 most phytotoxic; Fe-EDTA intermediate phytotoxic, Fe-DTPA less phytotoxic, and Fe-EDDHA least phytotoxic. Such rankings do not necessarily 21 apply when the chelate is EBDC fungicides in the Mn, Zn form.

22 It will be appreciated by those skilled in the art that beneficial effects 23 demonstrated in the Examples by the use of Cu-EDDHA will also be obtained when

I

WO 98/58546 PCT/US98/12264 1 the Mn, Zn and Fe forms EDDHA and other forms of heavy metal chelates are 2 employed.

In the claims which follow and in the preceding summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.

It is to be understood that a reference herein to a prior art publication does not constitute an admission that the publication forms a part of the common general knowledge a in the art in Australia, or any other country.

Claims (7)

1. A composition when used for controlling fungal and/or bacterial disease in plants comprising a fungicidally and/or bactericidally effective amount of a heavy metal chelate in an aqueous solution, wherein said effective amount of the heavy metal chelate has low or no phytotoxicity to plants, wherein the heavy metal is selected from the group consisting of zinc, manganese, copper, and combinations thereof, and wherein the chelate is selected from the group consisting of EDDHA, pEDDHA, EDDHMA and combinations thereof.

2. The composition of claim 1 wherein said heavy metal chelate is present in said aqueous solution in amount equal to from about 0.01 to about 1.0 pounds of the heavy metal chelate per acre.

3. The composition of claim 1 wherein said heavy metal chelate is selected from the group consisting of Cu- EDDHA, Cu-pEDDHA, Cu-EDDHMA, and combinations thereof. a 0 a a a a *ooo*o e a. a* a o o ao a.* a.* a ft 20

4. A method for controlling fungal and/or bacterial disease in plants comprising applying to a plant a composition comprising a fungicidally and/or bactericidally effective amount of a heavy metal chelate in an aqueous solution, wherein said effective amount of the heavy metal chelate has low or no phytotoxicity to plants, wherein the heavy metal is selected from the group consisting of zinc, C I manganese, copper, and combinations thereof, and wherein the chelate is selected from the group consisting of EDDHA, pEDDHA, EDDHMA and combinations thereof.

The method of claim 4 wherein said heavy metal chelate is present in said aqueous solution in amount equal to from about 0.01 to about 1.0 pounds of the heavy metal chelate per acre.

6. The method of claim 4 wherein said heavy metal chelate is selected from the group consisting of Cu- EDDHA, Cu-pEDDHA, Cu-EDDHMA, and combinations thereof.

7. A method for controlling fungal and/or bacterial disease in plants comprising applying to a plant a composition comprising a heavy metal chelate, the method being substantially as described herein with S: 20 reference to the Examples. Dated this 16 th day of October 2001 JOHN B TAYLOR By his Patent Attorney GRIFFITH HACK L 22