Ancient and Modern Day Pest Control
Many modern pest controls began in Socrates' garden. The
ancient Greeks and Romans excelled in many endeavors besides
philosophy, architecture, orgies and war. They also pioneered
many agricultural practices that are used by farmers and gardeners
today. In fact, ancient agriculturists developed many forms
of pest control that provided a foundation for today's battle
against plant pests.
Life on the farm was never as well documented as many other
aspects of classical Greece and Rome. However, several writings
remain from the ancient Mediterranean period. Products used
by Greek and Roman farmers had to be derived from animals,
plants, or minerals. They also needed to be easily obtainable.
In addition to what may be loosely termed "chemical pest
control methods", there were other remedies based on
folk magic. However, ancient chemical controls of fungus diseases,
weeds, insects, and rodents may be considered forerunners
of modern pesticides.
Ancient farmers of the eastern Mediterranean grew cereal grains,
fruit
and vegetables similar to our present crops. Not surprisingly,
they were plagued by many of the same weeds—wild oats,
burrs, nightshade, thistles, and bindweed; and insects—beetles,
caterpillars, and locusts—that threaten crops today.
Crop protection was in the hands of the gods, according
to the Greek writer, Xenophon. He wrote that men offered prayer
for crops and asked the blessing of the gods. Farmers and
gardeners today, of course, still heavily rely on celestial
assistance.
Ancient husbandmen also practiced a peck of folk remedies
to help rid their fields of pests. Hanging a crayfish or a
mare's skull in the garden would deter caterpillar infestations.
Worms (caterpillars) come in a variety of colors and shapes,
but all of them damage plants by eating holes in leaves. They
feed on most garden vegetables. Entire plants can be eaten
by these caterpillars if they occur in large numbers. These
can be easily controlled by using Dipel, Thuricide, Bio?Spray
or Biological Worm Killer. These materials contain the bacteria
Bacillus thuringiensis that kills only caterpillars and does
not harm beneficial insects. Good coverage and wetting upper
and lower leaf surfaces are necessary for best control. To
insure that wetting occurs, mix one teaspoon of a liquid detergent
per gallon of spray.
Diseases of millet could be prevented, it was said, by toting
a toad around a field at night—as long as the beast
was later buried in the middle of that field. On a more scientific
side, ancient agronomists discovered a relationship between
leaf rust and damp growing conditions. To control mildew,
they mixed ground?up roots and wild cucumber leaves with water
and sprinkled the mixture on vines. To fight rust and fungus
infestations, they used seed treatment and fumigation, including
smoke. They burned straw, crabs, fish, dung, and animal horns
in orchards and vineyards. Diseases of vegetable crops must
be prevented, not cured. There are two main diseases that
cause this disaster every spring. Early blight (Alternaria)
and Septoria leaf spot are the culprits. Early blight is characterized
by irregular and brown spots that first appear on older foliage.
With age, the spots show concentric rings forming a target
pattern. A yellow diffuse zone is formed around each spot.
Although this fungus disease can be observed throughout the
year, it is most common during the fruiting period. The more
fruit a plant has, the more susceptible to and disastrous
are the effects of an early blight infection. The fungus is
favored by both high humidity and high temperatures. The only
control is prevention that begins when the plant is transplanted.
During periods of high humidity, which includes most of the
spring, apply a fungicide weekly. The best fungicide to use
is one containing chlorothalonil (Ortho Daconil or Fertilome
Broad Spectrum Fungicide).
Varro can be credited with discovering the first chemical
weed killer in the first century B.C. He noted that amurca
made from crushed olives was toxic to ants, moles, and weeds.
Further, whenever amurca flowed from olive oil presses, the
ground became barren, although this was possibly due to salt
being added to olives before they were pressed. In any case,
Varro began recommending amurca application for all noxious
weeds. Amurca was the base ingredient for many pest remedies.
It was usually boiled in copper vessels and often mixed with
salt. Both copper and salt have pesticidal properties. Amurca
was used to fight insects as well as weeds. Palladius wrote
of mixing amurca and extracts of cucumber or lupins spiked
with urine to knock caterpillars off cabbage.
Virgil mentions the beginnings of a systematic approach
to weed control—that of burning cereal stubble after
harvest to cook weed seeds. In the fourth century B.C., Theophrastus
noted that certain weeds were associated with specific crops.
The phenomenon is akin to allelopathy, or the ability of some
plants to exude substances that are toxic to other plant species
nearby. Today's weed scientists are incorporating allelopathy
into weed control systems.
To battle the many insects that thrived in the mild Mediterranean
climate, farmers used the juices of hemlock, lupin and squill,
which packed a gladiator's kick when they were used as seed
treatments. These and other plant species contain poisonous
compounds that are capable of killing insects, larvae, and
small animals, as well as certain non-target species such
as people. To kill rats and mice that pilfered their granaries,
Roman growers set out poison bait laced with hellebore, hycoyamus,
hemlock or wild cucumber.
Some animal fats also have insecticidal properties, so Corinthian
orchard owners coated leaves with bear and goat fat. They
also dipped pruning knives in animal fat to reduce the spread
of bacterial and viral infection from tree to tree. Dedicated
fruit growers sometimes sprinkled tree leaves with a cow?dung?and?water
slurry to protect foliage from pests. Obviously this was the
first use of foliar feeding via manure "tea".