Betamix, Progress, and Betanex have a supplemental label for micro-rate applications. Micro-rates are very reduced postemergence herbicide rates which are "heated-up" with a modified (methylated) seed oil adjuvant. It is important to apply Micro-rates when weeds are small (1/8 in).

Micro-rates are an alternative postemergence (POST) program and do not replace preemergence herbicides. First timing of the micro-rate application is CRITICAL. Micro-rate applications can be made based on calendar date or Growing Degree Days. When applying by calendar date, scouting is critical to determine time of application. Make a broadcast application beginning 7-30 days after planting (weeds must be less than 1/8 inch tall--sugarbeet size does not matter unless herbicide rate is increased). Repeat this micro-rate application at 5-14 day intervals depending on temperature and moisture conditions (plan on seven-day intervals, if rainy weather is predicted apply after 5 or 6 days). Plan on a minimum of five micro-rate applications (spray weekly until sugarbeet canopy closure).

Weed and sugarbeet growth can change depending upon environmental conditions. Researchers at Michigan State University determined that applying micro-rates based on Growing Degree Days (GDD) can improve weed control and reduce sugarbeet injury compared to applying micro-rates based on calendar dates. Growing degree days in this case are based on air temperature. To calculate GDD for micro-rate applications, add the high and low air temperature over a 24 hour period, divide by 2 and subtract 34 ([high temp + low temp]/2 - 34). Example: High temp = 80 F, Low temp = 60 F, ((80 + 60) /2)) - 34 = 36 GDD for one 24 hr period. Begin accumulating GDD the day sugarbeets are planted. After the micro-rate application, reset GDDs to 0 and begin accumulating GDDs again. Research indicates that applying micro-rates at intervals of 225 GDDs provides the most consistent weed control and crop safety. However, the spray interval can be adjusted depending on weed population and soil properties. Weather station data will be available to calculate GDDs. You will find the information in April on the website www.michiganbeets.com. For help determining the proper interval for applying micro-rate applications, or using the BeetCast website, contact your agriculturist.

If you miss a micro-rate application, return to your "standard" postemergence herbicide splits. Micro-rates can be applied at any time as long as NO DEW is present on leaves. Apply 10-12 GPA. Do not tank mix the micro-rate program with both fungicides and insecticides.

Do NOT leave out Stinger, Upbeet OR methylated seed oil. A modified seed oil must be added for herbicide micro-rates to be effective at 1.5% v/v with a minimum of 1.0 pt/A at low spray volumes, 4-8 GPA. Various modified seed oils marketed in Michigan are Destiny (Agriliance), MSO Concentrate (Loveland) and MSO (Helena). It is recommended to apply micro-rates broadcast. If band applications are utilized, band width should be at least 11 inches wide. See label for proper mixing order in the spray tank. Always use a high quality MSO!

Nozzle plugging has been a concern with micro-rates, especially when using Betanex. To reduce potential for nozzle plugging, always preslurry Upbeet and add to the sprayer first after the water; keep spray volume below 15 GPA; do not let solution sit in the tank more than three hours and consider changing to nozzles with larger orifices.If you have any questions, contact your agriculturist.