Archive Article: 2000/04/28
WHAT is the best sequence to add tank mix products to the sprayer tank? All too often label information is inadequate and sometimes contradictory.
How, for example, do you cope with two or more product labels saying add first?
The following sequence list, based on formulation type, will assist operators when there are no clear instructions on labels, says Tom Robinson, spray applications specialist at Novartis. But remember that all other label conditions must be followed, he says.
WG – Water dispersible sulfonylureas;
WSB – Water soluble bag;
WG – Other water dispersible granules;
WP – Wettable powders.
Adjuvant listed on pesticide label
SC – Suspension concentrate (flowable);
SE – Suspo-emulsion;
EW – Oil in water emulsion;
EC – Emulsifiable concentrate;
SL – Soluble (aqueous) concentrate.
Other adjuvant
Trace element formulations;
Liquid fertiliser (approved).
Never add two products to the induction bowl or filter basket at the same time and ensure each product is completely dispersed before adding the next one, Mr Robinson advises.
Water-soluble bags should always be added at the beginning and agitated until fully dissolved. If not, the bags may interact with later additions, coagulate and block filters.
Solid trace elements such as manganese sulphate are another potential source of trouble. "Liquid formulations are far better," says Mr Robinson.
Water quality and low temperature can exacerbate incompatibilities. If in doubt about mixes not on labels, check for physical compatibility and crop safety with manufacturers.
• The Art of Spray Application, a booklet giving more information on tank mixes and other spraying issues, is available free from Novartis (01233-494150).