Method of controlling phytopathogenic diseases on turfgrass
The present invention relates to a method of controlling pythium blight on turfgrass, in particular low to moderate disease pressure, using a fungicidally effective non-phytotoxic amount of (A) chlorothalonil and (B) acibenzolar-s-methyl.
1. A method for controlling or suppressing cool-season pythium blight in 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 pythium blight 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 5000 g/ha.
9. The method of claim 1 , wherein acibenzolar-S-methyl is applied at the rate of from 5 to 12 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 Pythium 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, Buchloë, Cynodon, Eremochloa, Festuca, Lolium, Paspulum, Pennisetum, Phleum, Poa, Stenotaphrum or Zoysia.