Weed control from applications of aminopyralid, triclopyr, and an organosilicone surfactant

1. A herbicidal composition comprising a herbicidal mixture and an organosilicone surfactant, wherein the herbicidal mixture consists of a herbicidal effective amount of (a) aminopyralid or an agriculturally acceptable salt or ester thereof, and (b) triclopyr or an agriculturally acceptable salt or ester thereof;

wherein the acid equivalent weight ratio of (a) to (b) is from 1:2 to 1:20;

wherein the weight ratio of the organosilicone surfactant (in g ai/ha) to (a) (in g ae/ha) and (b) (in g ae/ha) in combination is from 1:1 to 1:8; and

wherein the organosilicone surfactant includes a polyalkyleneoxide-modified heptamethyltrisiloxane defined by Formula II

wherein

a is an integer ranging from 1 to 10;

b is an integer ranging from 1 to 30; and

R′″ is hydrogen or a C 1 -C 4 hydrocarbyl group.

2. The composition of claim 1 , wherein the acid equivalent weight ratio of (a) to (b) is from 1:7 to 1:10.

3. The composition of claim 1 , wherein (a) includes aminopyralid-triisopropanolammonium, aminopyralid-potassium, or combinations thereof.

4. The composition of claim 1 , wherein (b) includes triclopyr-triethylammonium, triclopyr-butotyl, or combinations thereof.

5. The composition of claim 1 , further comprising an agriculturally acceptable adjuvant.

6. The composition of claim 5 , wherein the agriculturally acceptable adjuvant includes a herbicide safener.

7. A method of controlling undesirable vegetation which comprises applying to vegetation or an area adjacent the vegetation or applying to soil or water, a composition comprising a herbicidal mixture and an organosilicone surfactant, wherein the herbicidal mixture consists of a herbicidal effective amount of (a) aminopyralid or an agriculturally acceptable salt or ester thereof, and (b) triclopyr or an agriculturally acceptable salt or ester thereof;

wherein the acid equivalent weight ratio of (a) to (b) is from 1:2 to 1:20;

wherein the weight ratio of the organosilicone surfactant (in g ai/ha) to (a) (in g ae/ha) and (b) (in g ae/ha) in combination is from 1:1 to 1:8; and

wherein the organosilicone surfactant includes a polyalkyleneoxide-modified heptamethyltrisiloxane defined by Formula II

wherein

a is an integer ranging from 1 to 10;

b is an integer ranging from 1 to 30; and

R′″ is hydrogen or a C 1 -C 4 hydrocarbyl group;

wherein (a) is applied in an amount of from 20-65 g ae/ha; and

wherein (b) is applied in an amount of from 200-400 g ae/ha.

8. The method of claim 7 , wherein the acid equivalent weight ratio of (a) to (b) is from 1:7 to 1:10.

9. The method of claim 7 , wherein (a) includes aminopyralid-triisopropanolammonium, aminopyralid-potassium, or combinations thereof.

10. The method of claim 7 , wherein (b) includes triclopyr-triethylammonium, triclopyr-butotyl, or combinations thereof.

11. The method of claim 7 , wherein the undesirable vegetation includes gorse, blackthorn, species of ash, bloody-twig dogwood, species of the genus Carex , Scotch broom, common hawthorn, and combinations thereof.

12. The method of claim 7 , wherein the undesirable vegetation is controlled for a period of at least 180 days after application.

13. The method of claim 7 , wherein (a) is applied in an amount of from 25-65 g ae/ha.

14. The method of claim 7 , wherein (b) is applied in an amount of from 250-400 g ae/ha.

15. The method of claim 7 , wherein the organosilicone surfactant is applied in an amount from 150-180 g ai/ha.

16. The method of claim 7 , wherein the undesirable vegetation is controlled for a period of at least 365 days after application.