Synthetic Chemicals/Word count for ‘analysis’=424
Total word count= 541
Will Fulton / Biniam Iyob
8:00 p.m.
Natural Pesticides from the Farm
Interpretation
Many synthetic pesticides are analogs of naturally occurring alkaloids. The ability
to synthesize chemical compounds from petrochemicals transfers profits from the farm to the
chemical companies. Farmers should eliminate synthetic chemicals and grow their own
pesticides.
Analysis
Herbivorous insects, mammals, bacteria, fungi and other organisms have led plants
through an epochal dance of speciation. Plants have tried thorns, mimicry, and the ability to
re-grow quickly when eaten, but their most successful defense against browsers of all sizes and
kingdoms has been the development of secondary metabolites which by odor or toxin repelled or
poisoned the offending herbivore. For thousands of years, human beings have found some of
these secondary metabolites, especially the alkaloids and terpenoids, to be of valuable use.
Humans have used them for medicinal and spiritual health enhancement, and as pesticides.
Generally, these were foraged. Often they were prepared in elaborate ceremonies. But many can
also be cultivated and prepared less elaborately and less ceremoniously. Following are just a few
examples of very effective pesticides which can be grown in the U.S..
Sweet Flag, Acorus calamus, an Araceae and hardy perennial, is semi-aquatic, insecticidal,
and oviposition inhibiting, and is native to the S.E. United States. It inhabits the edges of
streams, ponds and lakes. Grow it along swales and irrigation ditches. The leaves are known to
kill beetles, army and cabbage worms, fleas, fruitflies, weevils and borers. (Stoll, 2000, p 224)
Wormwood, Artemisia absinthium, an Asteraceae and hardy perennial is insecticidal and
acaricidal, and likes a Mediterranean climate (which Corvallis may soon become). It needs very
well drained soil but makes few other demands, does well in full sun to partial shade, and is quite
drought tolerant. Wormwood has been used for centuries as a moth repellant, general pesticide
and as a tea/spray to repel slugs and snails.
Epazote, Chenopodium ambrosioides, is an annual. The fruit contains substances toxic to corn
weevil (Tavares, 2005, pp. 319-323). The plant is used as a fumigant against mosquitoes and is also
added to fertilizers to inhibit insect larvae. ( Bown. D, 1995, p. 310 ) It propagates easily from seed,
likes moderately fertile soils, full sun, and tolerates both salt and a pH range from 5.3 to 8.2.
Neem, Azadirachta indica, is an insect growth regulator, which means that it abrupts
metamorphosis, such that juveniles never become mating adults. It also has repellent,
insecticidal, antibacterial, antifungal, and antifeedant qualities. (Prakash; Rao, 1997: pp. 35-103)
It likes a much warmer climate than Corvallis has now.
Ryania speciosa, is a shrub from South America. The principal alkaloid in this stem extract is
ryanodine. It is highly toxic to the fruit moth, coddling moth, corn earworm, European corn
borer, and citrus thrips, but it is ineffective against the cabbage maggot, cauliflower worm, and
boll weevil. It is moderately toxic to humans, fish and birds, but very toxic to dogs.
There are literally hundreds of others.
Evaluation
Inference
Some of the work sourced is more anthropology than experimental science.
Growing and preparing one’s own pesticides is labor intensive and therefore may only
find practitioners among small family farms, but any decrease in the 4.6 billion pounds of
synthetic pesticides America uses annually would be beneficial to the biosphere.
Explanation The end
of oil approaches. Those who rely on synthetic petrochemicals will lose
profits. Farms must localize both their markets and their sources.
Self regulation
The author has a strong antipathy toward chemical companies.
Bown, D., Encyclopedia of Herbs & Their Uses, DK Adult, London, 1995
Prakash, A.; Rao, J. (1997): Botanical pesticides in agriculture. CRC Press. USA
Stoll, G. (2000): Natural protection in the tropics. Margraf Verlag. Weikersheim.
Tavares MAGC, Vendramim JD (2005) Bioactivity of the Mexican-tea, Chenopodium ambrosioides L., towards
Sitophilus zeamais Mots. (Coleoptera : Curculionidae). Neotropical Entomology 34, 319-23