YERBA BUENA FARMS, JAMAICA
Tropical Organic Agriculture Research
Project
Natural Insecticides: Essential Oils and Kitchen Tips
Summer 2011
Our goal is to provide both information and effective products to support natural farming in Jamaica. We
will create pesticides based on essential oils distilled from common Jamaican plants and trees. We will also
test the effectiveness of natural pesticides that any Jamaican can make in their kitchen and make the
information widely available to farmers in different ways.
Essential Oil Study
Out of the many tropical plants that we might have used in this study, some, famous for being
insecticidal (like neem) were passed over, while guinea grass, which is famous only for being an
irritating pest, was included.
Early on, we decided that we needed a set of criteria to help us decide which plants or trees to study.
The plants we included were all:
1. Common and abundantly available;
2. Commercially farmed or had a fruit that was harvested on a large scale, creating byproducts that
could be used to make essential oil; or
3. Known to be insecticidal, or common sense suggested that they might be.
Neem was passed over because we know of only one neem tree on the island. Guinea grass was
included because it is such a notorious pest – to say that it is common and abundantly available is an
understatement. Surely, it must have some redeeming quality, some usefulness to balance the hardship
it represents to farmers! We added it out of hopefulness and curiosity.
The following is the list of plants and trees that we will use in the essential oil study:
Ackee Leaf and Pod
Bougainvillea
Cerasse
Guinea Grass
Guacu
Lemongrass
Orange
Papaya
Pimento Leaf and Berry
St. Vincent
Soursop/Custard Apple
Wild Basil
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Ackee Leaf and Pod
Ackee, Jamaica’s national fruit is poisonous unless handled properly. The leaves are used in tea, and the
ripe fruit is cleaned carefully, boiled and eaten. We’ll distill the leaves, and will (carefully!) experiment
to see if the pods, which are discarded during processing, can be used in a kitchen tip recipe.
http://nopr.niscair.res.in/bitstream/123456789/9399/1/NPR%203(2)%20101-102.pdf
Ackee Fruit Food poisoning: Unripe ackee fruit contains a chemical called hypoglycin A and B which affect
the central nervous system and fatty acid oxidation. Eating the unripe fruit can cause poisoning. Symptoms
can occur in as little as two hours but is generally 6 to 48 hours. The ackee fruit is found mainly in Jamaica,
West Africa, Central America, Sought Florida, southern California and Hawaii.
Bougainvillea
This beautiful flowering plant is so easy to grow; it blooms wildly on roadsides, uncared for yet healthy
and strong. Jamaicans use it purely for decoration.
Bougainvillea, which also goes by the botanical name Bougainvillea spectabilis, can be used to treat plants
infected by viral diseases. This natural pesticide can be prepared by mixing 200 grams of fresh
bougainvillea plant leaves with water and running the mixture through a blender. When it comes to eco
gardening, this mixture can be especially effective in treating tomato and beans plants infected by viral
diseases.
Cerasse
Also known as Bitter Melon, cerasse is extremely bitter. It’s used as a balancing and cleansing tea, as an
external cleanser (the vine bundled up and rubbed on the skin during a shower) for people with skin
problems, raw and juiced to induce abortion, as an insulin regulator by people with diabetes, etc. We
give it to our guests to bitter-up their blood, making them less attractive to mosquitoes.
On the Internet, I learned that it is used as an insecticide in Panama and in Haiti. It offends me to see
people clearing cerasse away like a worthless weed. If it works well as an insecticide, maybe people will
end up farming cerasse instead!
http://curezone.com/upload/PDF/Save_Your_Life_/Bitter_Melon.pdf
Guacu
Guacu is an aggressive vine that takes over any uncultivated area, growing both on the ground and in
the tree canopy. It is bitter and used both internally and externally in a bath or poultice when people
have sores or infection. We can’t find anything on the Internet about Guacu, but the pristine leaves of
any Guacu vine suggest that pests are not attracted to it at all. We are excited to experiment with this
plant – we’ll use it in every trial.
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Guinea Grass
Guinea grass is a nightmare – it can completely take over a cleared field in a matter of months, harbors
ticks, and is hard to kill. Even if you can dig out the roots, the seed will sprout in your field for years to
come. This grass can send even a dedicated environmentalist straight to the hardware store for the
most powerful herbicide.
We’ve never heard of any use for this plant, other than as food for animals. We’d like to distill the
essential oil and see what positive effect it might have in the vegetable garden.
http://www.plantzafrica.com/plantnop/panicummax.htm
Lemongrass
Lemongrass is common, perennial, and hardy. Hearsay tells us that is an ant repellant. We will find out
if lemongrass oil prevents ants from taking away the newly-sown seeds in a bed.
http://en.wikipedia.org/wiki/Lemongrass
Orange
Since there is a big citrus industry in Jamaica, and the orange juice factories can present us with their
waste material (the rinds) in great abundance, we are attracted to using orange oil. Many commercial
organic pesticides are made with orange oil as a main ingredient. We will use this as a general insect
repellant, and more specifically for repelling ants in the seed bed.
http://en.wikipedia.org/wiki/Orange_oil
Papaya
This is another plant that grows quickly and easily. Because it is farmed commercially, it is very
common. Jamaican cultural uses of the plant do not include using it as a pesticide. We will experiment
with using the stain from the tree and the green fruit and the essential oil from the leaves.
http://marsudiyanto-petrus.blogspot.com/2008/07/pesticide-from-papaya-leaves.html
Read more: The Properties of Papaya Leaf Insecticide | eHow.com
http://www.ehow.com/list_6790220_properties-papaya-leafinsecticide.html#ixzz1G776HXk9
Pimento Leaf and Berry
Every pimento season, tons of branches are broken off of pimento trees – the berries are harvested and
the leaves and twigs are discarded. We’d like to distill these leaves and see what we can do with them.
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There’s not much on the Internet or in the books I have, but with so much material going to waste, it
seems a shame not to try and see what pimento has to offer.
Recent research into using plant-derived products against PRM has produced some promising results (Kim
et al., 2004; George et al., 2010a). Preliminary work by Kim et al. (2004) found that essential oils from bay,
cade, cinnamon, clove bud, coriander, horseradish, lime dis 5F, mustard, pennyroyal,
pimento
berry, spearmint and thyme all gave 100% mite mortality in contact toxicity tests at a concentration of
0.07 mg of oil per cm 2. In similar work by George et al. (2010), 50 plant essential oils were assessed for
their toxic effect on D. gallinae with 1 in every 5 of the essential oils used, including thyme, tea tree and
garlic, giving 100% mite mortality. Further experiments by the same research group have found certain
essential oils to also work well as PRM repellents, whilst having no negative effect on non-target organisms,
hen welfare or egg production.
St. Vincent
Also known as ‘quick stick’, this tree can grow from just a stick being stuck in the ground. It is wellknown as an insecticide by people who read articles in the Internet, but is only used by Jamaicans as a
quick, fast growing fence or hedge. It is common and endlessly trimmed by people who don’t want their
fence becoming a line of tall trees.
http://pinoynegosyo.blogspot.com/2007/08/madre-de-cacao-as-natural-insecticide.html
Soursop/Custard Apple
These small trees grow in almost every yard. On the Internet, I read that the crushed seeds are an
insecticide, and I’ve found many do-it-yourself recipes that use the leaves. We’ll experiment with the
essential oil and check the usefulness of the recipes before we present it as a kitchen tip.
http://en.wikipedia.org/wiki/Annonaceae
Wild Basil
Basil is everywhere in Jamaica . It’s one of those wonderful plants that grow like any weed, without
needing to be seeded or cultivated, but is so useful and delicious; the word “weed” is too negative to be
used when describing it. I am pretty sure it’s as insecticidal as any basil, but there’s no cultural
knowledge of that, nor did I find much on the Internet to suggest that it’s used that way in other tropical
countries.
http://www.jamaicaobserver.com/westernnews/The-basil-controversy_7985837
http://pubs.acs.org/doi/abs/10.1021/jf035145e
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Vegetables
The vegetables we decided to work with were the ones that farmers tend to spray regularly as they
grow. Some plants, like tomato, can be grown without much spray. Others, like the ones in this list, get
sprayed with a cocktail of toxic chemicals on a weekly basis throughout the growing season.
Cabbage
Calaloo
Bok Choy
Broccoli
Corn
Cucumber
Watermelon
Okra
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Spray Schedule
We will start the garden the way most Jamaicans do: sowing the seeds en masse directly in a seedbed in
the garden, and then uprooting them and transplanting them to their prepared bed.
Seeds sown en masse are misted lightly with pesticide after being sown to prevent ants from taking
away the seeds.
Next, farmers spray the suckers (the young plants) while still in the seed bed. This is necessary because
they are stressed from being in such close quarters.
Next, the plants are sprayed again after being transplanted. This prevents pests from attacking them
when they are weakened from the move.
Finally, many farmers spray proactively, on a weekly schedule for the rest of the plant’s growing season.
Corn, cucumber, okra and watermelon, are direct-sown and have different schedules.
Corn gets sprayed in the hole and in its heart while young, then weekly after that.
Okra gets spray when it begins to fruit and weekly thereafter.
Cucumber and watermelon are sprayed in the hole as the seed is planted to repel mice, and weekly
after they start to grow.
We will follow this schedule with half of our plants to see if the oils are at least as effective as regular
pesticide, and with the other half, we will spray as minimally as possible to see if the oils are more
effective than regular pesticides. Many times, with regular pesticides, you see the pests returning in as
little as two days after application. We will experiment with dilution and with marrying the oils to soap
in the spray to increase the ability of the oils to stick to the plant – we want the oils to be effective over
a long period of time. Over time, as we see what effect each oil has on pests, we can combine oils to
have a more powerful impact. For example, we would combine an oil that is repellant with an oil that
can kill the pests that are already on the plant.
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Organic Farming Tips
Jamaicans are eager to learn about effective and easy ways to farm without chemical inputs. We and
our neighbors have all sacrificed a crop because we did not want to be exposed to toxic pesticides. In
addition to the essential oil product, we want to do tests of the helpful hints on how to farm organically
that can be found in any gardening book or on the web. Whatever tip we find effective, we will
publicize as widely as possible. We will focus solely on tips that are easy and can be home-made; if they
have a recipe, anyone can make them in their own kitchen with common ingredients.
This is a list of some of the tips we will test:

Use olive oil to repel ants. Oleic acid, repels bees and ants by simulating the "Smell of death"
produced by their decomposing corpses.

Aphids are repelled by banana stain.

Use cow’s milk as an insect repellent. Mix 1/2 cup of fresh, unpasteurized milk with 4 cups of
flour and 20 litres of water. It kills insect eggs and acts against some insects.

Chile, pepper (Capsicum frutescens). Collect two handfuls of chilies and dry.
Grind into a fine powder, taking care not to inhale too much of the highly irritating dust, mix
with 2 litres of water and soak overnight.
Onion extract is made by leaving the leaves for a few days in water, adding 1/100 soft soap,
sifting and spraying it (against aphids and caterpillars)
Stale beer is put outside in a shallow container to attract garden slugs, that then crawl
into the container and drown.
Garlic Extract: Made by soaking mushed garlic in water, adding soft soap at density of
1/100 (against insects)

Chalk. Mix 3–5 grams of chalk per litre of water. Soak for 12 hours if construction
grade chalk is used, 3– 4 days if natural chalk is used. Stir frequently and apply
directly. Dehydrates the insect when in contact. It can burn young plant tissue and
should therefore only be used on mature leaves.

To eradicate the caterpillars that attack cabbage, use wheat flour. Sprinkle flour on the plants
so as to form a thin layer. This flour will make the caterpillar could not breathe and die. Leave on
for 2 days, and then wash your cabbage from wheat flour.
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
Plant your carrots into a stale seed bed. To do this, prepare your planting bed and rake it
smooth. Then water it well, and wait about 10 days. The first crop of weeds seeds will
germinate, and can be destroyed with a hoe. Then plant your carrots without further disturbing
the soil. This will reduce subsequent weeding by about 80%.

Bougainvillea (Bougainvillea spectabilis). Mix 200 grams of fresh leaves per litre
of water. Mix at least 5 minutes in a blender. Used against several virus diseases in tomatoes
and beans.

Garlic and onion. (Allium sativum, A. cepa). Mix 500 grams finely
chopped material in 10 litres of water. Allow to ferment for one week. Dilute with
another 10 litres of water. Incorporate into the soil.

Soursop, Custard Apple
Plant parts with insect controlling properties: seeds, leaves, unripe fruit.
Target pests: aphid, caterpillars, green bug and Mediterranean fruit fly.
Preparation: 500 grams of custard apple leaves, boil in 2-1/2 litres of water, until only 1/4 of the
original is left, then dilute this mixture into 15-20 litres of water. This is good enough for one
hectare.

Basil
Plant parts with insect controlling properties: leaves and stems.
Target pests: fruit fly, leaf miners, red spider and mites.
Preparation: 100g basil leaves dipped in to 1 litre of water. This should be soaked overnight in
water. Filter the mixture and add 1ml of liquid soap, stir properly. Dilute into 10-15 litres of
water.

Chilies
Plant parts with insect controlling properties: fruit
Target pests: ants, aphid, caterpillars and slugs.
Preparation: 500g of chilies, dip into 3 litres of water for 10-15 minutes. Add 30g of soap to cling
to plant. Add 3 more litres of water, filter and then spray the plants.
Note: You can additionally include tobacco, garlic, onion, citrus, alcohol, neem and lime.

Garlic
Plant parts with insect controlling properties: bulbs
Target pests: aphids, house flies, mites, white fly, bacteria, cucumber and scab.
Preparation: 3 bulbs of garlic, ground finely, add some kerosene, keep for 2 days. Add 1
tablespoon of soap powder, stir and filter and add 15-20 litres of water.

Ginger
Plant parts with insect controlling properties: rhizome
Target pests: American bowl worms, aphid, thrips, white fly, and mango anthracnose.
Preparation: 500g of crushed garlic add 10ml of kerosene oil kept overnight. Next day remove
outer skin of ginger and make ginger paste. In another vessel add 100g green chilies, mixed with
50ml of water and add 30g of liquid soap as emulsifier. Solution is stirred and filtered and 10-15
ml of water added.
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
Neem
Plant parts with insect controlling properties: seeds and leaves.
Target pests: American boll weevils, ants, locusts, leaf hoppers, leaf miners, mites, scales,
termites, thrips, white fly.
Preparation: 1 kg of neem leaves dipped into 2 litres of water and left overnight. Boil it 15-20
minutes until 1/4 is left. Dilute with 10-15ml of water.

Papaya
Plant parts with insect controlling properties: leaves, seed, unripe fruit flower.
Target pests: thrips and fruit fly, mosaic virus and powdery mildew.
Preparation: 1 kg of finely shredded leaves, placed in 1 litre of water and squeezed through a
cloth. Take 1 litre of soap solution, dilute it in 10-15 ml water.

Tobacco (not considered organic)
Plant parts with insect controlling properties: leaves and stalk
Target pests: aphids, caterpillars, leaf miners, mites and thrips.
Preparation: boil 4 litres of water, add 1/2 kg of tobacco leaves and 1 tablespoon of lime. Dilute
it with 10-15 litres of water. (Note: we have to add safety information with this tip).

Tumeric
Plant parts with insect controlling properties: rhizome
Target pests: aphids, caterpillars, mites and rice leaf hoppers.
Preparation: 500g of turmeric rhizomes chopped and soaked overnight, dilute into 2 litres of
water and again dilute into another 10-15ml of water.

African marigold flowers are also useful as it stops air born disease from entering the farm. It
should be planted on the border of the plot.

Beets
We plant the first beets about 4 weeks before the last spring frost. When we are preparing the
garden, we will spread a little wood ash from our stove over the beds where we plan to plant
beets. Old-time farming books recommend this practice to help beets globe up.
Each beet seed is actually a seed cluster, and will produce more than one seedling. Absolutely
critical vegetable farming advice: beets must be thinned early and often to form a good size
root. If you ignore this vegetable farming advice, you will end up with greens but few roots.
Allow about 150 plants or about 30 feet of row per family of 4.

While many seed companies recommend planting bush beans 3 inches apart, we plant the seeds
about 6” apart in in all directions in our wide beds. When the seedlings are well up, we give
them a little boost with ½ strength fish emulsion. Beans don’t like sprinklers, so use drip hose to
give them about an inch of water a week if there is no rain.

Do not overdo nitrogen fertilizers. The soft growth they produce is very attractive to aphids.
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
Plant tomatoes in trenches; that is, we strip off all but the top cluster of leaves, and bury the
entire stem of the plant horizontally in a trench. This consistently produces a strong, prolific
plant.

To avoid tobacco mosaic virus:
The most common method of transferring the virus from plant to plant is on contaminated
hands and tools. Workers who transplant seedlings should refrain from smoking during
transplanting and wash their hands frequently and thoroughly with soap and water. Tools used
in transplanting can be placed in boiling water for 5 minutes and then washed with a strong
soap or detergent solution. Dipping tools in household bleach is not effective for virus
decontamination. Any seedlings that appear to have mosaic symptoms or are stunted and
distorted should be removed and destroyed. After removing diseased plants, never handle
healthy plants without washing hands and decontaminating tools used to remove diseased
plants.

To eradicate caterpillars that infest yellow corn, use the leaves of tomato (Lycopersicon
esculentum). Slice 1-2 handheld tomato leaf, then soak in ¼ liter of water for 80-10 hours, then
strain and add another ¼ liter of water. Then this natural pesticide can be used.

Mint deters white cabbage moth and ants.

For cucumber beetles:
Spread any type of onion skins on the soil around the planted areas.
Heavy mulching can deter cucumber beetles from laying eggs in the ground near plant stems
and may hinder feeding by larvae migrating to fruits. This cultural control method, however,
does not protect the leaves against attack from adult insects. Injury to fruit by tunneling of
larvae is dependent on very moist soil as fruits ripen. Limiting irrigation at this time can
minimize damage
Mix a spray of 1 ounce wood ashes, 1 ounce hydrated lime and 1 gallon water. Spray upper and
lower leaf surfaces. Hydrated lime is a powdered substance. Or use a spray of hot peppers,
water and garlic.
You can squish cucumber beetles by hand in the early morning; you can find them hiding out in
the blossoms.
Trellising plants can make leaves less accessible to insect larvae and may decrease egg-laying.
Like mulching, trellising does not protect plants against attack by adult insects
Plant any type of beans with cucumber.

A well-drained soil dries fast and permits timely field operations. In well-drained soil oxygen is
able to reach the root zone to promote optimal root health. Optimal root growth happens best
in soils without drainage problem.
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
Walking on wet soil will pack soil down and push out the air and water will not pass through the
soil. There will not be enough space for the roots to grow. Soil that is too packed will not give
good crop yield. Wait until the ground is dry before you till it or start planting.
Interns will choose the tips that they will test.
This document will evolve as the project progresses.
Over time, we will add information about how we will publicize information, biographies of the interns
working on the project, links to blogs written by the interns, and pictures.
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