Defining
degrees of control on pesticide labels
Before a crop protection
product company submits a product for registration, many trials must be conducted
to determine human toxicity, environmental impact and potential injury to plants.
In the U. S., crop protection products are submitted for registration without
a review of efficacy data, whereas Canada requires data to support the level of
control (efficacy) a product has against a specific pest on a specific host. The
product is generally tested at the proposed label rate and twice, half and possibly
one quarter the label rate to determine the lowest rate at which the product is
effective. The amount of pest activity (insect feeding, disease development, weed
survival) in these treatments is rated relative to untreated control plots. This
information is then used to develop the label. A set of terms have been developed
to describe the degree of control that a product provides:
Control
- A consistent level of pest management, as defined by commercial standards
and expectations in the market, when compared to untreated control plots. In general,
pest control ratings would range between 85% - 100%.
Suppression
- A consistent level of pest management that is less than full control, as defined
by commercial standards and expectations in the market, when compared to untreated
control plots. In general, pest control ratings would range between 65% - 85%.
Reduction in damage from /partial suppression
- A level
of pest management that is less than suppression, as defined by the commercial
standards and expectations in the market. This label claim will be considered
for non-conventional pesticides. This claim may also be considered for conventional
pesticides following discussions with PMRA on a case-by-case basis. In general,
pest control ratings would range between 30% - 65%. This degree of control would
be more of an incidental activity of the product against pests other than the
main one(s) on the label.
Many of the newer, "softer" pest
control products do not give the immediate "knock down" that older products
did. You will notice the term "suppression" on some of the labels of
these newer products. Under severe pest pressure, these products are not likely
to give acceptable commercial control. However, under trace to moderate pressure,
when used in rotation with more effective products, they may provide satisfactory
control when used with other control methods in an IPM program
