herbicidecalculation

Herbicides:

• Are applied in small amounts• Must be combined with liquid or solid carrier

(inert material) for even distribution and accurate measurement of the amount of herbicide to be used.

• Have rates expressed in terms of commercial product needed per unit area (per hectare)

Herbicides:

• In publications, herbicide rates are expressed in terms of amount of active ingredient (a.i.) per hectare

• Since there are different concentrations of the a.i. available commercially, rates are expressed in amount of product per hectare rather than amount of a.i. per hectare can be confusing.

• Inert ingredient (carrier)• Active ingredient• % active ingredient of the herbicide

product is used to calculate the amount to be applied

Herbicidepackage content

Rate desired (kg a.i./ha) X area (ha) x 100

Amount (kg or L) = ----------------------------------------------------------------

Herbicide concentration (%)

 

 

Rate desired (kg a.i./ha) X area (ha) x 10

Amount (g or ml) = ----------------------------------------------------------------

Herbicide concentration (%)

 

Equations for calculating herbicide amount needed

Example

 For solid formulation

 

How much butachlor granules (5% a.i.) is required to treat a 28m2 at the rate of 1.5 kg a.i./ha?

 

 Amount (g) of product to treat 28m2

  1.5 x 28 x 10

= -------------------------------- = 84 g

5

Equations for calculating herbicide amount needed

 For liquid formulations

 

How much glyphosate (36% a.i.) is required to treat a 2000m2 plot at the rate of 1.0 kg a.i./ha?

 

Amount (g) of product to treat 2000m2

1.0 x 2000 x 10

= -------------------------------- = 555 ml

36

 

Equations for calculating herbicide amount needed