trends & technology
“ Neem oil
IS EXTRACTED FROM THE SEEDS
OF THE NEEM TREE, AZADIRACHTA INDICA, AN
EVERGREEN THAT IS NATIVE TO INDIA.”
TYPES OF NEEM OIL PRODUCTS
The seeds of the neem tree have high concen-
trations of azadirachtin, which the active
chemical in the plant. However, it is important
to understand the different forms of neem
oil because each one has a different way of
attacking pests. These different forms are a
result of different processing methods.
When you extract the natural oils from the
seeds you get the most complete form of
neem oil. You will see this in products labeled
as “cold-pressed” neem oil. Some products
further process the oil by using alcohol to
extract the azadirachtin. When this is done,
the azadirachtin separates and you are left
with clarified hydrophobic extract of neem
oil. Many neem oil products on the market
will actually be this form of neem oil, without
the azadirachtin, and are simply referred
to as neem oil. The separated azadirach-
tin is the main ingredient in many commer-
cial pesticides. You can know for sure which
form you are buying by looking for the active
ingredient on the label.
Clarified hydrophobic extract of neem oil
works on soft-bodied insects. It blocks the
pores that allow them to breathe and thus
70
grow cycle
smothers them. It must make contact with
the insects in order to work, so it is import-
ant to cover every surface of the plant when
spraying since many pests hang out on the
underside of the leaves. It effectively treats
more than 200 species of insects and works
especially well with aphids, caterpillars,
whiteflies, spider mites, mealy bugs, and
scales. This form of neem oil is also an effec-
tive fungicide. It can prevent many fungal
and bacterial diseases, including powdery
mildew, rust, wilt, scab, black spot, leaf spot,
and fire blight.
Azadirachtin affects insects as an insect
growth regulator, anti-feedant, repellent,
sterilant, and oviposition inhibitor. It works
as a stomach poison and must be ingested
by insects in order to work. It affects their life
cycle by preventing them from transition-
ing into their next stage of development and
laying eggs. Azadirachtin doesn’t work as
fast as synthetic pesticides, but this mecha-
nism reduces the population of pests in your
garden over time. It is most effective to use
azadirachtin early in the season so that you
catch pests earlier on in their life cycles when
treatment is most effective.