Controlling pesticide and other residues in herbs and spices 55
available to control them are limited, as much research has not been conducted in this
area.
The Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) regulates the
pesticides being used to control insect and mite pests of herbs and spices in the USA.
According to this law any chemical used for controlling pests must be registered by
the Environmental Protection Agency (EPA). Section 2ee of the FIPRA not only
allows use of pesticides as per specific instructions on the pesticide label, but also
requires that the target must also be specified on the product label. This law dramatically
limits the number of insecticides that are allowed to be used on herbs since few
products contain mention of this ‘minor crop’ thus technically controlling, by default,
use of many pesticides on herbs.
An ideal IPM strategy for spices and herbs should include use of Bacillus thuringiensis
for control of armyworms (1st and 2nd instars), loopers and salt marsh caterpillars;
insecticidal soaps (e.g. M-Pede®) for control of whiteflies, aphids, leafhoppers, plant
bugs, spider mites and thrips; azadirachtin to control a variety of insects including
leaf miners, fungus gnats, gypsy moths, western flower thrips, mealy bugs, armyworms,
aphids, loopers, cutworms, leaf rollers, leaf hoppers, webworms, spruce budworms
and sawflies. Products containing azadirachtin (extracted from neem tree) are considered
to be ‘insect growth regulators’, which work by interfering with the insects’ key
moulting hormone, ecdysone, to prevent them from moulting from one life stage to
the next. Egg and adult stages of insects are not affected by azadirachtin application
and have anti-feedant properties. Garlic water is also used to prevent pests like ants,
aphids, grasshoppers, ‘leaf loopers’, leaf rollers, spiders, spider mites, thrips and
whiteflies, though claims are made that this product kills insects and mites.
Whenever using a herbal product or product mixture for the first time on a plant
or plant’s growth stage, a few plants should be tested and observed for several days
to determine if that spray will harm the plant in any way. Leaf yellowing, burning,
deformation or drop are some of the symptoms to be looked for. Plants in flower or
in stress are more likely to display such phototoxic reactions. There may be other
products that are specifically used on one or more herbs. For example, numerous
Fig. 2.8 Strict quality checking for chemical residues and other customer requirements.