Control of aquatic weeds with endothall and ALS-inhibiting agent

A method for controlling aquatic weeds in a body of water, comprising:

• providing in the body of water a synergistically effective amount of a herbicidal combination including an ALS-inhibiting herbicide and endothall, so as to control the aquatic weeds;
• wherein said providing comprises adding the endothall to the body of water prior to adding the ALS-inhibiting herbicide or simultaneously with the ALS-inhibiting herbicide to the body of water;
• wherein the ALS-inhibiting herbicide is selected from the group consisting of penoxsulam, imazamox, and bispyribac sodium;
• wherein said providing comprises providing the endothall at a level of about 0.1 to about 3.5 ppm in the body of water;
• and
• with the further proviso that:
• (i) where the ALS-inhibiting herbicide is penoxsulam, the penoxsulam is applied to the body of water to provide a penoxsulam level of about 2.5 to 50 ppb in the body of water;
• (ii) where the ALS-inhibiting herbicide is imazamox, the imazamox is applied to the body of water to provide an imazamox level of about 0.02 to about 0.15 ppm in the body of water:
• and
• (iii) where the ALS-inhibiting herbicide is bispyribac sodium, the bispyribac sodium is applied to the body of water to provide a bispyribac sodium level of about 0.01 to about 0.25 ppm in the body of water.