Image 70 DG herbicide is labeled for use on Centipede grass and does list that it can be used to aid in the control of and reduce competition from bahiagrass. Though we will say that all of our experts in our company and others that we reach out to for further advice in this field agree that removing Bahiagrass from Centipede, or vice versa, cannot be done. While some universities may have had success with certain products working in controlled environments for them, there are no products on the market that we are aware of that are labeled or proven to work for your needs. Anything that would kill the Bahiagrass would also kill the centipede as the overall DNA of the plants are too similar to selectively kill one and not the other. The best recommendation would be to spot treat the bahia with a Roundup type product and then reseed heavily with centipede to try and smother out the bahia and keep it from coming back. If you choose to use a product recommended on a university's site you are more than welcome to, and you can search by both product name and active ingredient to see what we carry that you can try. We apologize for not being able to give you the answer you were looking for, but please let us know if you have any other questions!
Image 70 DG will treat sandbug (grassbur) To prevent sandburs you should apply Barricade as a pre-emergent in the late fall. Sandburs are easier to prevent than to try to get rid of once they have invaded your yard. Both products can be used as directed on the product labels on Bermudagrass.
Image 70 is labeled for use on St. Augustine lawns, however it is always important to keep in mind that any herbicides will create stress on the lawn. In general, you do not want to make applications when high temperatures (over 85 degrees), drought, disease, or similar conditions are causing stress on the lawn. According to page 5 of the product label:
"Best tolerance occurs under totally dormant or optimal growing conditions. When turfgrass is growing under marginal conditions, such as low temperatures, drought stress, compaction, etc., temporary yellowing or browning can occur and recovery may take 2 to 4 weeks."
You will need .20-.26 oz per 1,000 sq ft. You will need to use a hand pump sprayer and uniformly spray the product over the specified area. Also Image 70 DG does NOT come with a scooper or measuring device. This product is difficult to measure unless you have a scale or some way to measure .26 ounces to mix with a gallon of water.
Image 70 DG does come in a liquid form, which is Image Kills Nutsedge. This has the same active ingredient but in a lesser amount.
Acclaim Extra is labeled for sandburs and can be used inside of your boom sprayer with no issues. The mix rate is 20 oz. per 40 - 80 gallons of water per acre.