SELECTIVE WEED CONTROL

Abstract

The present invention provides a method of selectively controlling unwanted vegetation at a locus comprising a crop and the unwanted vegetation, wherein the method comprises applying to the locus a herbicidal composition comprising: —a. bicyclopyrone; b. a nitrogen-based fertilizer additive; and c. an ALS-inhibiting herbicide. The invention further provides an herbicide composition comprising (a) bicyclopyrone, (b) a nitrogen additive, and (c) an ALS-inhibiting herbicide.

Claims

1. A method of selectively controlling unwanted vegetation at a locus comprising a crop and the unwanted vegetation, wherein the method comprises applying to the locus a herbicidal composition comprising:— a. bicyclopyrone; b. a nitrogen-based fertilizer additive; and c. an ALS-inhibiting herbicide.

2. A method according to claim 1, wherein the nitrogen-based fertilizer additive is selected from ammonium sulfate and Urea Ammonium Nitrate.

3. A method according to claim 1, wherein the ALS-inhibiting herbicide is selected from the group consisting of an imidazilinone herbicide, a pyrimidinylthiobenzoic acid herbicide, a sulfonylaminocarbonyltriazolinone herbicide, a sulfonylurea herbicide and a triazolopyrimidine herbicide.

4. A method according to claim 3, wherein the ALS-inhibiting herbicide is the sulfonylurea herbicide mesosulfuron.

5. A method according to claim 3, wherein the ALS-inhibiting herbicide is the triazolopyrimidine herbicide pyroxsulam.

6. A method according to claim 1, wherein the herbicidal composition further comprises bromoxynil.

7. A method according to claim 1, wherein the bicyclopyrone is applied to the locus at a rate from 37.5 to 50 g ai/ha and the ALS-inhibiting herbicide is applied at a rate from 10-60 g ai/ha.

8. A method according to claim 1, wherein components (a), (b) & (c) are applied post-emergence to the locus.

9. A method according to claim 1, wherein the crop is wheat.

10. A method according to claim 1, wherein the unwanted vegetation comprises Bromus tectorum.

11. A herbicide composition comprising: a. bicyclopyrone; b. a nitrogen-based fertilizer additive; and c. an ALS-inhibiting herbicide.

12. A herbicide composition according to claim 11, wherein the ALS-inhibiting herbicide is mesosulfuron and/or pyroxsulam.

13. A herbicide composition according to claim 11, further comprising an additional herbicide.

14. A herbicide composition according to claim 13, wherein the additional herbicide is bromoxynil.

15. Use of an ALS-inhibiting herbicide to reduce the herbicidal effect of bicyclopyrone in crop plants.

Description

EXAMPLES

Example 1

[0033] A study is performed to examine the crop phytotoxicity observed using the method of the present invention. The test crop species is Spring Wheat. Treatments are applied as outlined in Table 1. *Bicyclopyrone is applied as TALINOR™ (which contains 3.41% bicyclopyrone and 23.16% bromoxynil) in conjunction with CoAct+ at 2.75 fl oz/ha. All treatments are applied with a non-ionic surfactant (R-11 available from Wilbur-Ellis Company) at 0.25% v/v in the spray tank. Where UAN is employed, UAN 32 (45% ammonium nitrate, 35% urea, 20% water) is used at 15% v/v in the spray tank. Crop plants are visually assessed for % weed control at 15, 22 and 30 days after application (DAA).

TABLE-US-00009 TABLE 1 DAA % Phytotoxicity Rate g/ha 15 22 30 1 Non-treated n/a 0 0 0 control 2 Bicyclopyrone* 37.5 0 0 0 3 Bicyclopyrone* + 37.5 19 15 4 UAN 4 Mesosulfuron + 15 0 0 0 UAN 5 Pyroxsulam + 18 0 0 0 UAN 6 Bicyclopyrone* + 37.5 + 15 0 0 0 Mesosulfuron 7 Bicyclopyrone* + 37.5 + 15 0 0 0 Mesosulfuron + UAN 32 8 Bicyclopyrone* + 37.5 + 18 0 0 0 Pyroxsulam 9 Bicyclopyrone* + 37.5 + 18 0 0 0 Pyroxsulam + UAN

[0034] As can be seen the use of the nitrogen additive (UAN) along with bicyclopyrone causes some phytotoxicity in the wheat (row 3). This phytotoxicity is completely removed when various ALS-inhibiting herbicides are added to the composition (rows 7 and 9).

Example 2

[0035] A study is performed to examine the weed control obtained using the method of the present invention. Test species is Bromus tectorum (BROTE). Treatments are applied as outlined in Table 2. *Bicyclopyrone is applied as TALINOR™ (which contains 3.41% bicyclopyrone and 23.16% bromoxynil) in conjunction with CoAct+(a sodium bicarbonate containing adjuvant) at 2.75 fl oz/ha. All treatments are applied with a non-ionic surfactant (R-11 available from Wilbur-Ellis Company) at 0.25% v/v in the spray tank. Where UAN is employed, UAN 32 (45% ammonium nitrate, 35% urea, 20% water) is used at 15% v/v in the spray tank. The plants are visually assessed for % weed control at 15, 22 and 30 days after application (DAA).

TABLE-US-00010 TABLE 2 DAA % Phytotoxicity TRT Composition Rate 15 22 30 1 Nontreated n/a 0 0 0 control 2 Bicyclopyrone* 37.5 6 5 5 3 Bicyclopyrone* + 37.5 6 3 3 UAN 4 Mesosulfuron + 15 45 72 84 UAN 5 Pyroxsulam + 18 48 83 100 UAN 6 Bicyclopyrone* + 37.5 + 15 20 13 5 Mesosulfuron 7 Bicyclopyrone* + 37.5 + 15 48 69 70 Mesosulfuron + UAN 8 Bicyclopyrone* + 37.5 + 18 45 76 90 Pyroxsulam 9 Bicyclopyrone* + 37.5 + 18 33 91 100 Pyroxsulam + UAN

[0036] As can be seen the use of the nitrogen additive (UAN) along with bicyclopyrone and various ALS-inhibiting herbicides (rows 7 and 9) continues to provide extremely good control of the test species.