Get your inner geek out. The herbicide mode of action (MoA) classifications have been updated. Now we’re joining the rest of the world and aligning with an internationally recognised system. You would be familiar with our old letter system to classify herbicide groups (i.e. Group G’s), but over the next few years, you will see a transition to the new number system.

Why are they causing you this headache?

Well, there’s a pretty good reason for it – we were running out of letters. By using numbers, the new system can accommodate an infinite number of new herbicide MoA’s coming to the market in the future. So it does make sense.

This year, you can expect to see changes on herbicide labels to include the new mode of action. There will be a period in which you will have a mixture of drums with each class system, but the transition should be fully complete by 2024.

See below for changes:

A – 1
B – 2
C – 5,6
D – 3
E – 23
F – 12
G – 14
H – 27
I – 4
J – 15
K – 15
L – 22
M – 9
N – 10
O – 29
P – 19
Q – 13,34
R – 18
T – 30
Z – 0,31

For more information on what’s what, head to CropLife’s website here.

And for a printer friendly version of their table: here.