What rate would you recommend for spraying Decision through a handgun?

by Paul | Posted in Questions & Answers | No comments yet. | 1361 views on this post

QUESTION: What rate would you recommend for spraying Decision through a handgun – can you give me a rate per 60 litres?

It’s not as simple as it sounds.

Decision is normally applied only as an area spray, with a boom or roster sprayer.  So the rate is based on amount of product per unit of area.  That is, for example, 50g per hectare. 

It’s difficult to give a rate per unit of water for handgun spraying, unless 1 know for how much area is covered by that operator using that handgun with each 100L of water.  Did Malcolm say how much area he would spray with 100L water?  Or with however many litres of water his handgun spray tank holds?

It becomes even worse when I say that Decision has three different application rates, based on the identity of the target species.  

  • Chickweed is 30g/hectare,
  • annual buttercup is 50g/hectare, and
  • giant buttercup is 65g/hectare.  

So the highest rate is more than double the lowest rate.  So to be of help we really need to know the weed you are spraying?

Let’s make some assumptions:

  • Assumption 1 -You spray, with your handgun unit, an area of 50M x 50M with 60L of water.  So that’s a quarter of a hectare.  You spray to the point of dampness, but not runoff.  That is, the leaf is visibly and uniformly moist but not dripping wet.
  • Assumption 2 - You are spraying annual buttercups.

So based on these assumption

The per hectare rate for annual buttercups is 50g of Decision, but you are going to spray just a quarter hectare with your 60L handgun tank.  

So you need 50g/4 = 12.5g of Decision in 60L of water.

Note:  If ANY of these assumptions is wrong, then 12.5g Decision per 60L of water will be incorrect.

Not quite as simple as it sounds.



Comments (0)

Write a comment

Your Name:

Rating: Bad           Good

Enter the code in the box below:

Your Comment: Note: HTML is not translated!
Copyright - Rainbow & Brown Ltd - 2014 - all rights reserved