Herbicidal mixtures comprising L-glufosinate and their use in corn cultures

Abstract

The present invention relates to herbicidal mixtures and their methods and uses for controlling undesirable vegetation in glufosinate-tolerant corn, wherein the herbicidal mixtures comprise L-glufosinate and and at least one herbicidal compound II selected from clethodim, cycloxydim, haloxyfop, haloxyfop-methyl, haloxyfop-P, haloxyfop-P-methyl, quizalofop, quizalofop-ethyl, quizalofop-tefuryl, quizalofop-P, quizalofop-P-ethyl, quizalofop-P-tefuryl, chlorimuron, chlorimuron-ethyl, foramsulfuron, halosulfuron, halosulfuron-methyl, iodosulfuron, iodosulfuron-methyl-sodium, nicosulfuron, prosulfuron, rimsulfuron, thifensulfuron, thifensulfuron-methyl, tritosulfuron, imazamox, imazamox ammonium, imazapic, imazapic ammonium, imazapyr, imazapyr isopropylammonium, imazethapyr, imazethapyr ammonium, diclosulam, flumetsulam, florasulam, metosulam, thiencarbazone, thiencarbazone-methyl, atrazine, simazine, terbuthylazin, bromoxynil and its salts and esters, bentazone, bentazone-sodium, pyridate, carfentrazone, carfentrazone-ethyl, flumiclorac, flumiclorac-pentyl, flumioxazin, fluthiacet, fluthiacet-methyl, saflufenacil, sulfentrazone, tiafenacil, trifludimoxazin, picolinafen, bicyclopyrone, clomazone, isoxaflutole, mesotrione, sulcotrione, tembotrione, tolpyralate, topramezone, fenquinotrione, glyphosate, glyphosate dimethylammmonium, glyphosate-isopropylammonium, glyphosate-potassium, glyphosate-trimesium (sulfosate), pendimethalin, acetochlor, butachlor, dimethenamid, dimethenamid-P, metazachlor, metolachlor, S-metolachlor, pethoxamid, flufenacet, pyroxasulfone, 2,4-D and its salts and esters, clopyralid and its salts and esters, dicamba and its salts and esters, quinclorac, quinclorac dimethylammonium, quinmerac,diflufenzopyr, diflufenzopyr-sodium, cinmethylin, MCPA and its salts and esters and other compounds.

Claims

1. A method for controlling undesirable vegetation in glufosinate tolerant corn, which method comprises applying to the undesirable vegetation or the locus thereof or applying to the soil or water an herbicidal mixture comprising a) L- glufosinate and its salts as compound I, and b) a herbicidal compound II comprising pyroxasulfone, wherein: L-glufosinate comprises more than 70% by weight of the L-enantiomer, and the weight ratio of compound I to compound II is from 50:1 to 1:5.

2. The method of claim 1, wherein compound I in the herbicidal mixture 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 method of claim 1, wherein compound I in the herbicidal mixture is L-glufosinate-ammonium.

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

5. A pesticidal mixture, comprising the compounds I and II as defined in claim 1.

6. A pesticidal composition, comprising a liquid or solid carrier and the mixture of claim 5.

7. The method of claim 1 wherein the glufosinate tolerant corn is a transgenic corn plant.

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

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

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

11. The method of claim 1, wherein the weight ratio of compound I to compound II is from 8:1 to 1:5.

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

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

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

(4) 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.

(5) Test Method:

(6) 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.

(7) Products:

(8) L-Glufosinate: 5% EC formulation

(9) Saflufenacil: 342 g/l SC formulation

(10) Compound II-83: 5% EC formulation (Compound II-16: ethyl [3-[2-chloro-4-fluoro-5-(1-methyl-6-trifluoromethyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-3-yl)phenoxy]-2-pyridyloxy]acetate)

(11) Trifludimoxazin: 500 g/l SC formulation

(12) Pyroxasulfone: 85% WG formulation

(13) Pethoxamid: 5% EC formulation

(14) 2,4-D dimethylammonium salt: 500 g/l SL formulation (concentration calculated for 2,4-D acid)

(15) Dicamba dimethylammonium salt: 480 g/l SL formulation (concentration calculated for dicamba acid)

(16) Bicyclopyrone: 5% EC formulation

(17) Dimethenamid-P: 720 g/l EC formulation

(18) S-Metolachlor: 960 g/l EC formulation

(19) Sulfentrazone: 480 g/l SC formulation

(20) Weeds in the Study:

(21) TABLE-US-00004 EPPO Code Scientific Name ABUTH Abutilon theophrasti ECHCG Echinochloa crus-galli AVEFA Avena fatua SETVI Setaria viridis COMBE Commelina benghalensis KCHSC Kochia scoparia CHEAL Chenopodium album CYPIR Cyperus iria ERICA Erigeron Canadensis, Conyza canadensis

Example 1

Post Emergence Treatment with the Mixture of L-Glufosinate with Saflufenacil

(22) TABLE-US-00005 Herbicidal activity against Application rate in g ai/ha ECHCG L-Glufosinate Saflufenacil Found Calculated 400 — 65 — — 0.5 0 — 400 0.5 97 65 200 — 0 — — 0.5 0 — 200 0.5 35  0

Example 2

Post Emergence Treatment with the Mixture of L-Glufosinate with Compound II-83 (ethyl [3-[2-chloro-4-fluoro-5-(1-methyl-6-trifluoromethyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-3-yl)phenoxy]-2-pyridyloxy]acetate)

(23) TABLE-US-00006 Herbicidal activity against Application rate in g ai/ha CYPIR L-Glufosinate Compound II-83 Found Calculated 200 — 0 — — 0.25 0 — 200 0.25 35 0

Example 3

Post Emergence Treatment with the Mixture of L-Glufosinate with Trifludimoxazin

(24) TABLE-US-00007 Herbicidal activity against Application rate in g ai/ha ECHCG L-Glufosinate Trifludimoxazin Found Calculated 400 — 65 — — 0.25 10 — 400 0.25 75 69 200 — 0 — — 0.25 10 — 200 0.25 33 10

Example 4

Post Emergence Treatment with the Mixture of L-Glufosinate with Pyroxasulfone

(25) TABLE-US-00008 Herbicidal activity against Application rate in g ai/ha ABUTH L-Glufosinate Pyroxasulfone Found Calculated 200 — 65 — — 50 70 — 200 50 100 90 200 — 65 — — 25 40 — 200 25 100 79

Example 5

Post Emergence Treatment with the Mixture of L-Glufosinate with Pethoxamid

(26) TABLE-US-00009 Herbicidal activity against Application rate in g ai/ha ABUTH AVEFA L-Glufosinate Pethoxamid Found Calculated Found Calculated 150 — 55 — 0 — — 100 0 — 0 — 150 100 98 55 40 0  75 — 0 — 0 — —  50 0 — 0 —  75  50 35  0 5 0

Example 6

Post Emergence Treatment with the Mixture of L-Glufosinate with 2,4-D dimethylammonium Salt

(27) TABLE-US-00010 Application rate in g ai/ha 2,4-D as dimethyl- Herbicidal activity against ammonium AVEFA SETVI L-Glufosinate salt Found Calculated Found Calculated 100 — 35 — 30 — — 140 0 — 0 — 100 140 65 35 65 30 100 — 35 — 30 — —  70 0 — 0 — 100  70 40 35 65 30

Example 7

Post Emergence Treatment with the Mixture of L-Glufosinate with Dicamba dimethylammonium Salt

(28) TABLE-US-00011 Application rate in g ai/ha Dicamba as dimethyl- Herbicidal activity against ammonium SETVI L-Glufosinate salt Found Calculated 100 — 30 — — 140  30 — 100 140  80 51 100 — 30 — — 70 0 — 100 70 65 30 100 — 30 — — 35 0 — 100 35 60 30

Example 8

Post Emergence Treatment with the Mixture of L-Glufosinate with Bicyclopyrone

(29) TABLE-US-00012 Application rate in g ai/ha Herbicidal activity against Bicyclo- COMBE ECHCG L-Glufosinate pyrone Found Calculated Found Calculated 100 — 0 — 0 — — 2 10 — 0 — 100 2 30 10 55 0 100 — 0 — 0 — — 1 0 — 0 — 100 1 25  0 30 0

Example 9

Post Emergence Treatment with the Mixture of L-Glufosinate with dimethenamid-P

(30) TABLE-US-00013 Herbicidal activity against Application rate in g ai/ha KCHSC L-Glufosinate Dimethenamid-P Found Calculated 200 — 90 — — 1000 70 — 200 1000 100 97 200 — 90 — —  500 0 — 200  500 100 90

Example 10

Post Emergence Treatment with the Mixture of L-Glufosinate with S-metolachlor

(31) TABLE-US-00014 Herbicidal activity against Application rate in g ai/ha CHEAL L-Glufosinate S-Metolachlor Found Calculated 100 — 0 — — 1000 75 — 100 1000 85 75 100 — 0 — —  500 20 — 100  500 85 20

Example 11

Post Emergence Treatment with the Mixture of L-Glufosinate with Sulfentrazone

(32) TABLE-US-00015 Herbicidal activity against Application rate in g ai/ha ERICA L-Glufosinate Sulfentrazone Found Calculated 75 — 90 — — 2.5  0 — 75 2.5  100 90 75 — 90 — — 1.25 0 — 75 1.25 100 90