Herbicidal mixtures comprising L-glufosinate or its salt and at least one photosynthesis inhibitor

Abstract

The present invention relates to herbicidal mixture comprising L-glufosinate or its salt and at least one photosynthesis inhibitor. The invention furthermore relates to a method for controlling undesirable vegetation in burndown programs, in industrial vegetation management and forestry, in vegetable and perennial crops and in turf and lawn.

Claims

1. A herbicidal mixture comprising a) L-glufosinate and its salts as compound I; and b) at least one photosynthesis inhibitor as compound II selected from the group consisting of fluometuron, diuron, and thidiazuron; wherein L-glufosinate comprises more than 70% by weight of the L-enantiomer.

2. The herbicidal mixture of claim 1, wherein compound I is selected from the group consisting of L-glufosinate-ammonium, L-glufosinate-sodium as L-glufosinate salts, and L-glufosinate as free acid.

3. The herbicidal mixture of claim 1, wherein compound I is L-glufosinate-ammonium.

4. The herbicidal mixture of claim 1, wherein L-glufosinate comprises more than 80% by weight.

5. The herbicidal mixture of claim 1, wherein compound II is selected from the group consisting of fluometuron and thidiazuron.

6. The herbicidal mixture of claim 1, wherein the weight ratio of compound I to compound II is from 1000:1 to 1:500.

7. A pesticidal composition, comprising a liquid or solid carrier and the mixture of claim 1.

8. A method for controlling undesirable vegetation comprising applying the mixture of claim 1 to a locus where undesirable vegetation is present or is expected to be present.

9. The method of claim 8, comprising application of the mixture as defined in claim 1 prior to emergence of the crop.

10. The method of claim 8, comprising application of the mixture as defined in claim 1 prior to planting the crop.

11. The method of claim 8, wherein the crop is selected from rice, maize, pulse crops, cotton, canola, small grain cereals, soybeans, peanut, sugarcane, sunflower, plantation crops, tree crops, nuts and grapes.

12. The method of claim 8, wherein the crop is selected from glufosinate tolerant crops.

13. The method of claim 8, wherein compounds I and II of the mixture as defined in claim 1 are applied simultaneously, that is jointly or separately, or in succession.

14. The herbicidal mixture of claim 1, wherein L-glufosinate comprises more than 90% by weight of the L-enantiomer.

15. The herbicidal mixture of claim 1, wherein L-glufosinate comprises 95% by weight of the L-enantiomer.

16. The herbicidal mixture of claim 1, wherein compound II comprises fluometuron.

17. The herbicidal mixture of claim 1, wherein the weight ratio of compound I to compound II is from 50:1 to 1:5.

18. The herbicidal mixture of claim 17, wherein compound II is fluometuron.

19. The herbicidal mixture of claim 17, wherein compound II is diuron.

20. The herbicidal mixture of claim 17, wherein compound II is thidiazuron.

Description

BIOLOGICAL EXAMPLES

(1) Synergism can be described as an interaction where the combined effect of two or more compounds is greater than the sum of the individual effects of each of the compounds. The presence of a synergistic effect in terms of percent control, between two mixing partners (X and Y) can be calculated using the Colby equation (Colby, S. R., 1967, Calculating Synergistic and

(2) Antagonistic Responses in Herbicide Combinations, Weeds, 15, 21-22):

(3) $E=X+Y-\frac{XY}{100}$

(4) When the observed combined control effect is greater than the expected (calculated) combined control effect (E), then the combined effect is synergistic.

(5) The following tests demonstrate the control efficacy of compounds, mixtures or compositions of this invention on specific weeds. However, the weed control afforded by the compounds, mixtures or compositions is not limited to these species. The analysis of synergism or antagonism between the mixtures or compositions was determined using Colby's equation.

(6) Test Method:

(7) The culture containers used were plastic flowerpots containing loamy sand with approximately 3.0% of humus as the substrate. The seeds of the test plants were sown separately for each species and/or resistant biotype. For the pre-emergence treatment, the active ingredients, which had been suspended or emulsified in water, were applied directly after sowing by means of finely distributing nozzles. The containers were irrigated gently to promote germination and growth and subsequently covered with transparent plastic hoods until the plants had rooted. This cover caused uniform germination of the test plants, unless this had been impaired by the active ingredients. For the post-emergence treatment, the test plants were first grown to a height of 3 to 15 cm, depending on the plant habit, and only then treated with the active ingredients which had been suspended or emulsified in water. For this purpose, the test plants were either sown directly and grown in the same containers, or they were first grown separately as seedlings and transplanted into the test containers a few days prior to treatment. Depending on the species, the plants were kept at 10-25° C. or 20-35° C., respectively. The test period extended to 20 days after treatment. During this time, the plants were tended, and their response to the individual treatments was evaluated. The evaluation was carried out by using a scale from 0 to 100. 100 means no emergence of the plants or complete destruction of at least the above-ground parts, and 0 means no damage, or normal course of growth. Data shown are the mean of two replications.

(8) Products:

(9) L-Glufosinate: 5% EC formulation

(10) Diuron: 5% EC formulation

(11) Fluometuron: 5% EC formulation

(12) Thidiazuron: 500 g/l SC formulation

(13) Weeds in the Study:

(14) TABLE-US-00003 EPPO Code Scientific Name AVEFA Avena fatua ABUTH Abutilon theophrasti SETVI Setaria viridis

Example 1: Post Emergence Treatment with the Mixture of L-Glufosinate with Diuron

(15) TABLE-US-00004 Herbicidal Application activity against rate in g ai/ha AVEFA L-Glufosinate Diuron Found Calculated 300 — 20 — — 250 30 — 300 250 70 44 300 — 20 — — 125 20 — 300 125 50 36

Example 2: Post Emergence Treatment with the Mixture of L-Glufosinate with Fluometuron

(16) TABLE-US-00005 Herbicidal Application activity against rate in g ai/ha ABUTH L-Glufosinate Fluometuron Found Calculated 75 — 0 — — 250 20 — 75 250 35 20 75 — 0 — — 125 0 — 75 125 35 0

Example 3: Post Emergence Treatment with the Mixture of L-Glufosinate with Thidiazuron

(17) TABLE-US-00006 Herbicidal Application activity against rate in g ai/ha SETVI L-Glufosinate Thidiazuron Found Calculated 150 — 70 — — 50 0 — 150 50 80 70 75 — 0 — — 50 0 — 75 50 10 0