WEEDS!!!!!

Asked April 7, 2013, 1:54 PM EDT

Looking for advice on weed control on these Elliott's they have been in the ground 2 years.last year I applied tank mix of Sinbar 1/2 lb.,Diuron 1 3/8 lb., Solicam 2 1/2 lb. per acre. Biggest problem seems to be grasses in the crown. Any advice will be greatly appreciated. Four acres (4000 bushes) located Grand Junction. I'll attach a pic of the latest soil test report

Van Buren County Michigan blueberries blueberry production blueberry soils blueberry weed control

5 Responses

The herbicide mix you used should have done a pretty good job against annual grasses and the clump of grass is now a perennial grass. The weed control you have now is excellent. Besides your normal preemergence herbicide application you will want to use a grass specific herbicide. These materials will not harm the blueberries because they are specific to grasses. If you are not going to pick blueberries off the field this year you can use Fusilade, otherwise you will need to use Poast or Select Max. These materials work best if they are applied to actively growing grasses so the early spring in the next few weeks is the time to get them. If you wait a while and the soil dries out and the grass stops growing they don't work as well. Eric Hanson spoke a little bit about grass herbicides last year at a meeting and gave out a handout
http://blueberries.msu.edu/publications/meeting_handouts
More complete information is available in E154 The Michigan Fruit Management Guide
http://msue.anr.msu.edu/news/2013_michigan_fruit_management_guide_available_at_msu_extension_booksto...

You might also be interested in added sulfur to some of your fields
http://msue.anr.msu.edu/news/soil_test_before_you_plant_blueberries

Thanks for the help. In response to the P.H. I missed it prior to planting and trying to play catch-up applied 400lbs.per acre (200 last spring 200 fall) planning 200 this spring. Think it might work?

Yes it will take a while. Notice the relationship between the soil pH and the amount and percentage of calcium (Ca). Essentually the bacteria in the soil convert the sulfur to Sulfate in the soil and leach the calcium out of the soil. All this takes place in the spring, summer and fall when the soil is warm and moist. I would sample the soil pH in the fall and add all the sulfur 400 pounds in the spring adding part in the fall doesn't do much since the soil is to cold (below 60F) for the bacteria to work. I would not add any more than the 200 you plan this spring as I have seen people get in trouble with too much sulfur. You may need to only apply to the high pH parts of the field soon as the soil pH might get where you want it in part of the field.
Are you irrigating and what is the pH of the water?

Thanks again,
Yes I have the ability to drip from a well with a Ph of 7.4 Or overhead from a pond with a Ph of 7.3 I do have an injector setup on the drip (mazzie) Would it be advantagious to try injecting something to try to lower the Ph thru drip?

Irrigating with water that has a pH up over 7 will cause problems because lots of irrigations will raise the soil pH. Injecting acid into the drip irrigation system to lower the pH to about 4.5 or 5 would be really good but probably you would need much finer control of the amount of acid you are injecting into the water than just the suction from a venture injector which draws the material in by drop of pressure. The amount of acid you need to inject requires that you know what the calcium and magnesium in the water is so you can calculate the amount of acid to inject for a given amount of water. You actually need a pump to inject a give amount of acid that you can adjust the amount. The one grower I have who did that bought several pumps and finally had to use a less concentrated (more expensive) sulfuric acid to inject..
You should talk with your irrigation equipment supplier about this.