Method of controlling phytopathogenic diseases on turfgrass

Abstract

The present invention relates to a method of controlling dollar spot on turfgrass, in particular low to moderate disease pressure, using a fungicidally effective non-phytotoxic amount of (A) chlorothalonil and (B) acibenzolar-s-methyl.

Claims

1. A method for controlling or suppressing dollar spot in cool-season turfgrass, comprising applying to the cool-season turfgrass or to the locus of the cool-season turfgrass, a fungicidally effective non-phytotoxic amount of a combination comprising (A) chlorothalonil and (B) acibenzolar-S-methyl, wherein (A) is applied at a rate of from 2,000 to 10,000 g/ha and (B) is applied at a rate of from 4 to 20 g/ha, wherein the combination of (A) and (B) is applied pre-disease or under low to moderate dollar spot disease pressure present in the turfgrass.

2. The method of claim 1, wherein the weight ratio of chlorothalonil to acibenzolar-S-methyl is from 300:1 to 600:1.

3. The method of claim 1, wherein chlorothalonil and acibenzolar-S-methyl are applied simultaneously together, separately, or in succession.

4. The method of claim 1, wherein a fungicidally effective non-phytotoxic amount of a composition comprising a mixture of chlorothalonil and acibenzolar-S-methyl is applied to the turfgrass or to the locus of the turfgrass.

5. The method of claim 1, using a composition comprising a combination of (A) and (B).

6. The method of claim 5, wherein the composition of (A) and (B) further comprises adjuvants, solvents, carrier, surfactants or extenders.

7. The method according to claim 6, wherein the composition comprises from 0.01 to 90% by weight of the combination of (A) and (B), from 10 to 99.99% of a carrier and from 0 to 20% of a surfactant.

8. The method of claim 1, wherein chlorothalonil is applied at the rate of from 3000 to 10000 g/ha.

9. The method of claim 1, wherein acibenzolar-S-methyl is applied at the rate of from 5 to 16 g/ha.

10. The method of claim 1, wherein the combined amount of chlorothalonil and acibenzolar-S-methyl that is applied to the turfgrass or to the locus thereof is between about 3000 to 5000 g/ha.

11. The method according to claim 1, wherein the phytopathogenic disease is caused by one or more phytopathogenic fungi selected from the group consisting of Sclerotinia homeocarpa, Lanzia or Moillerodiscus spp.

12. The method according to claim 1, wherein the turfgrass is an annual or perennial Gramineae belonging to at least one of the genera Agropyron, Agrostis, Axonopus, Bromus, Buchlo, Cynodon, Eremochloa, Festuca, Lolium, Paspulum, Pennisetum, Phleum, Poa, Stenotaphrum or Zoysia.

Description

FORMULATION EXAMPLE

(1) TABLE-US-00001 Suspension concentrate Active ingredients 40% Propylene glycol 10% Nonylphenol polyethylene glycol ether 6% (15 mol of ethylene oxide) Sodium lignosulfonate 10% Carboxymethylcellulose 1% Silicone oil (in the form of a 75% emulsion in water) 1% Water 32%

(2) In preparing and SC, the finely ground active ingredients are mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired dilution can be obtained by dilution with water. Using such dilutions, living plants as well as plant propagation material can be treated and protected against infestation by microorganisms, by spraying, pouring or immersion.

(3) The following examples are for illustrative purposes only. The examples are not intended as necessarily representative of the overall testing performed and are not intended to limit the invention in any way.

BIOLOGICAL EXAMPLES

(4) Enhanced control of turf dollar spot (Sclerotinia homoeocarpa) when acibenzolar-S-methyl is applied in combination with chlorothalonil is claimed. Control of turf dollar spot (Sclerotinia homoeocarpa) with reduced rates of acibenzolar-S-methyl plus chlorothalonil is also claimed.

Example 1. Disease Control

(5) Daconil Action (54% chlorothalonil and 0.176% acibenzolar-S-methyl) and Quali-Pro Chlorothalonil 720 were applied at golf course fairway recommended rates of 2 fluid ounces per 1000 square feet of turf and reduced rates of 1.82, 1.59 and 1.3 fluid ounces per 1000 square feet of turf. These rates are equivalent to the following:

(6) TABLE-US-00002 TABLE 1 Rate-fluid acibenzolar- ounces/1000 Chlorothalonil S-methyl Treatment sq. ft. g ai/ha g ai/ha Daconil Action 2.0 4600 9.2 Daconil Action 1.82 4160 8.3 Daconil Action 1.59 3640 7.3 Daconil Action 1.3 2980 6.0 Quali-Pro 2.0 4600 Chlorothalonil 720 Quali-Pro 1.82 4160 Chlorothalonil 720 Quali-Pro 1.59 3640 Chlorothalonil 720 Quali-Pro 1.3 2980 Chlorothalonil 720

(7) Trials were conducted on creeping bentgrass (Agrostis stolonifera) and arranged in randomized complete block designs with four replications. Treatments were applied on a 14 day schedule. Typically 6 applications were applied per trial. Percent turf area exhibiting dollar spot symptoms were assessed throughout the trial period. Turf quality was also evaluated.

(8) Dollar spot developed to significantly damaging levels at all locations. In Table 2, average number of dollar spot loci across ratings is provided within and across trials 1-5. In Table 3, percent dollar spot control is provided within and across trials 1-5. In Table 4, average number of dollar spot loci across ratings is provided within and across trials 6-8. In Table 5, percent dollar spot control is provided within and across trials 6-8.

(9) All rates of Daconil Action (2.0, 1.82, 1.59, and 1.3 fluid ounces) were equal to or superior to the 2 oz rate of Quali-Pro Chlorothalonil 720. This includes the recommended label rate of 2.0 fluid ounces as well as reduced rates of 1.82, 1.59 and 1.3 fluid ounces. The 1.3 ounce rate of Daconil Action was numerically equal to the 2.0 and 1.82 fluid ounce rate of Quali-Pro Chlorothalonil 720 and significantly (P=0.10) superior to the 1.59 and 1.3 fluid ounce rates.

(10) These data support the claim that Daconil Action (acibenzolar-S-methyl plus chlorothalonil) provides enhanced control of turf dollar spot (Sclerotinia homoeocarpa) over chlorothalonil applied alone. Applying acibenzolar-S-methyl in combination with chlorothalonil may allow for as much as a 30% rate reduction without loss of disease control.

(11) Daconil Action is a unique blend of a multiple-site contact fungicide (chlorothalonil) with acibenzolar-S-methyl a systemic compound used for control of disease through induction of host plant resistance. The mode of action of acibenzolar-S-methyl mimics the natural systemic activated resistance (SAR) response found in most plant species. This SAR response does not involve direct activity against the target pathogens but relies on the plants natural defense mechanism.

(12) TABLE-US-00003 TABLE 2 Average counts of dollar spot loci across all ratings dates within and across all trials 1-5. Total Dollar Spot Counts oz/ Trial Trial Trial Trial Trial 1000 1 2 3 4 5 sq. ft. PA* CT* MI* WI* NJ* AVG** 1 Untreated 124.1 114.3 235.3 220 476.4 234.0 Check 2 Daconil 2.0 14.88 40.6 31 106.7 64.9 51.6 Action 3 Daconil 1.82 22.53 34.9 36.2 83.6 61.9 47.8 Action 4 Daconil 1.59 6.8 47.6 58.5 110.2 101.4 64.9 Action 5 Daconil 1.3 23.3 52.6 91.3 124.2 112.6 80.8 Action 6 Quali-Pro 2.0 36.7 50.2 74.9 121.1 106 77.8 Chlorothalonil 7 Quali-Pro 1.82 15.9 104.8 76.2 122.4 122.1 88.3 Chlorothalonil 8 Quali-Pro 1.59 58.7 41.6 131.9 195.4 124.5 110.4 Chlorothalonil 9 Quali-Pro 1.3 33.68 86.6 129.5 260.7 145.6 131.2 Chlorothalonil *Average number of dollar spot loci or infections across all rating dates within trials. **Average number of dollar spot loci or infections across all rating dates and locations.

(13) TABLE-US-00004 TABLE 3 Percent dollar spot control across all ratings within and across all trials 1-5. % Control Trial Trial Trial Trial Trial oz/1000 1 2 3 4 5 Treatment sq. ft. PA* CT* MI* WI* NJ* AVG** 1 Untreated 0 0 0 0 0 0.0 Check 2 Daconil 2.0 88 64 87 52 86 75.4 Action abc*** 3 Daconil 1.82 82 69 85 62 87 77.0ab Action 4 Daconil 1.59 95 58 75 50 79 71.3a-d Action 5 Daconil 1.3 81 54 61 44 76 63.3de Action 6 Quali-Pro 2.0 70 56 68 45 78 63.5cde Chlorothalonil 7 Quali-Pro 1.82 87 8 68 44 74 56.4ef Chlorothalonil 8 Quali-Pro 1.59 53 64 44 11 74 49.1fg Chlorothalonil 9 Quali-Pro 1.3 73 24 45 19 69 38.6g Chlorothalonil *Average percent control of dollar spot across all rating dates within trials. **Average percent control dollar spot across all rating dates and locations. ***Means with same letter not different, LSD (P = 0.10)

(14) TABLE-US-00005 TABLE 4 Average counts of dollar spot loci across all ratings dates within and across all trials 6-8. Total Dollar Spot Counts oz/1000 Trial 6 Trial 7 Trial 8 sq. ft. IN* CT* WI* AVG* 1 Untreated Check 9.95 115.67 32.03 52.6 2 Daconil Action 2.0 1.49 11.66 19.81 11.0 3 Daconil Action 1.82 1.26 9.4 17.01 9.2 4 Daconil Action 1.59 1.72 15.69 15.85 11.1 5 Daconil Action 1.3 2.10 31.81 20.58 18.2 6 Quali-Pro Chlorothalonil 2.0 2.31 28.4 30.01 20.2 7 Quali-Pro Chlorothalonil 1.82 1.79 20.95 16.65 13.1 8 Quali-Pro Chlorothalonil 1.59 2.96 22.94 20.71 15.5 9 Quali-Pro Chlorothalonil 1.3 2.25 44.29 19.34 22.0 *Average number of dollar spot loci or infections across all rating dates within trials. **Average number of dollar spot loci or infections across all rating dates and locations.

(15) TABLE-US-00006 TABLE 5 Percent dollar spot control across all ratings within and across all trials 6-8. % Control oz/ Trial Trial Trial 1000 6 7 8 Treatment sq. ft. IN CT WI AVG 1 Untreated Check (9.95) (115.67) (32.03) (52.6) 2 Daconil Action 2.0 85.0 89.9 38.15 79 3 Daconil Action 1.82 87.3 91.87 46.89 82.5 4 Daconil Action 1.59 82.7 86.4 50.15 78.9 5 Daconil Action 1.3 78.89 72.49 35.74 65.39 6 Quali-Pro Chlorothalonil 2.0 76.7 75.4 6.30 61.5 7 Quali-Pro Chlorothalonil 1.82 82.0 81.8 48.01 75.0 8 Quali-Pro Chlorothalonil 1.59 70.2 80.16 35.34 70.5 9 Quali-Pro Chlorothalonil 1.3 77.3 61.7 39.61 58.1 *Average percent control of dollar spot across all rating dates within trials. **Average percent control dollar spot across all rating dates and locations.

Example 2. Turf Quality

(16) Enhanced control of dollar spot with acibenzolar-S-methyl plus chlorothalonil was also apparent in turf quality ratings (Tables 6-7-). The lowest rate of Daconil Action, 1.3 fluid ounces, was numerically equal to the 2.0, 1.82 and 1.58 fluid ounce rate of Quali-Pro Chlorothalonil 720 and significantly (P=0.10) superior to the 1.3 fluid ounce rate. Applying acibenzolar-S-methyl in combination with chlorothalonil may allow for as much as a 30% rate reduction. This rate reduction will result in equal disease control with no loss in turf quality.

(17) TABLE-US-00007 TABLE 6 Turf Quality Rating (1-9 Scale, 9 best) Across All Ratings Within and Across All Trials 1-5. AVG Turf Quality/trial All ratings Oz/ Trial Trial Trial Trial Trial 1000 1 2 3 4 5 Treatment sq. ft. PA* CT* MI* WI* NJ AVG** 1 Untreated 5.4 6.2 4.2 5.9 5.0 5.3 g Check 2 Daconil 2.0 7.7 7.5 6.4 6.4 6.7 6.9 ab Action 3 Daconil 1.82 7.2 7.7 6.3 6.5 6.8 6.9 abc Action 4 Daconil 1.59 7.8 7.3 6.0 6.5 6.4 6.8 bcd Action 5 Daconil 1.3 7.2 7.4 5.6 6.6 6.1 6.6 cde Action 6 Quali-Pro 2.0 7.1 7.2 6.0 6.5 6.3 6.6 b-e Chlorothalonil 7 Quali-Pro 1.82 7.4 6.7 5.7 6.5 6.1 6.5 def Chlorothalonil 8 Quali-Pro 1.59 6.8 7.7 5.2 6.4 6.2 6.5 ef Chlorothalonil 9 Quali-Pro 1.3 7.1 6.5 5.0 6.4 6.0 6.2 f Chlorothalonil *Average turf quality (1-9 scale) across all rating dates within trials. **Average turf quality (1-9 scale) across all rating dates and locations. ***Means with same letter not different, LSD (P = 0.10)

(18) TABLE-US-00008 TABLE 7 Turf Quality Rating (1-9 Scale, 9 best) Across All Ratings Within and Across All Trials 6-8. AVG Turf Quality/trial All ratings Oz/ Trial Trial Trial 1000 6 7 8 Treatment sq. ft. IN* CT* WI* AVG** 1 Untreated Check 3.0 3.7 5.7 4.1e*** 2 Daconil Action 2.0 5.7 6.7 6.4 6.2 a 3 Daconil Action 1.82 6.2 6.8 6.2 6.4 a 4 Daconil Action 1.59 5.7 5.8 6.3 6.0 ab 5 Daconil Action 1.3 5.1 5.5 6.1 5.6 bcd 6 Quali-Pro Chlorothalonil 2.0 5.4 5.7 5.6 5.6 bcd 7 Quali-Pro Chlorothalonil 1.82 5.1 6.0 6.3 5.8 bc 8 Quali-Pro Chlorothalonil 1.59 5.0 5.5 6.2 5.5 cd 9 Quali-Pro Chlorothalonil 1.3 4.8 5.0 6.1 5.3 d *Average turf quality (1-9 scale) across all rating dates within trials. **Average turf quality (1-9 scale) across all rating dates and locations. ***Means with same letter not different, LSD (P = 0.10)

(19) These data support the claim that Daconil Action (acibenzolar-S-methyl plus chlorothalonil) provides enhanced control of turf dollar spot (Sclerotinia homoeocarpa) over chlorothalonil applied alone. Applying acibenzolar-S-methyl in combination with chlorothalonil may allow for as much as a 30% rate reduction without loss of disease control or turf quality.

(20) Although the invention has been described with reference to preferred embodiments and examples thereof, the scope of the present invention is not limited only to those described embodiments. As will be apparent to persons skilled in the art, modifications and adaptations to the above-described invention can be made without departing from the spirit and scope of the invention, which is defined and circumscribed by the appended claims. All publications cited herein are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual publication were specifically and individually indicated to be so incorporated by reference.