When should I apply Manipulator on my wheat?

Posted by Jeremy Boychyn | MSc P.Ag | Agronomy Research Extension Specialist

If you are applying chlormequat chloride (Manipulator, Belchim Crop Protection Canada) on your wheat, the time is upon us. GS 31-32 typically occurs between 3-6 leaf and 1-3 tiller stage, so scouting for ideal timing should be occurring while addressing herbicide planning and application. Unlike ethrel, which can cause significant yield impacts if timed inappropriately, the potential impact of mistimed application of chlormequat chloride is mainly reduced or lost efficacy. Nevertheless, this is still a significant fiscal and time impact to the farm. No one likes wasted field passes. Therefore, close monitoring of ideal chlormequat chloride staging is important.

To assess timing, you will need a razor, a ruler with centimeter increments, a surface to dissect plants stems on, and some patience.

Here are the steps:

  1. Go to a representative area of the field and pull a few plants
  2. Remove extra tillers from the plants so you are left with only the main stem
  3. Use the razor (I find a knife does a poor job of dissection due to the blade being wide and causing damage to the stem making node identification more challenging) to slice up the center of the stem so the stem is split in half
  4. Measure distance from the tillering node to the 1st nodeIf the 2nd node is present, measure the distance from the 1st node to the 2nd node
  5. If the 2nd node is present, measure the distance from the 1st node to the 2nd node
  6.  Beginning of ideal timing is: 1st node is 1cm away from the tillering node
  7. As the plant continues to grow after its reached beginning of ideal timing, the 1st node will push further away from the tillering node and a new node (the 2nd node) will develop from the 1st node and push up away from that 1st node.
  8. The end of ideal timing is when the 1st node is equal to or greater than 1cm away from the tillering node and the 2nd node is equal to 2cm above the 1st node.Once the 2nd node is more that 2cm away from the 1st node, you are past ideal timing.
  9. Once the 2nd node is more that 2cm away from the 1st node, you are past ideal timing.
  10. Conduct this in a few areas of the field until you are confident in your fields staging.
  11. Apply chlormequat chloride when majority of the field is at GS 31-32.
Click for a tutorial video on staging
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