In-the-know organic gardeners (and grandmothers) in Córdoba, Argentina will tell you an organic and powerful secret for pest control: the juice of the chinaberry, or the Paraiso, as it is known in South America.
Not surprisingly, these berries (which here are known as “venenitos” / “little poisons”) contain a naturally-ocurring chemical compound which is has some of the same pesticidal properties of the more well-known neem tree extract.
This chemical, called Azadirachtin, inhibits reproductive cycles among treated herbivore pests, buts degrades organically and poses no threats to treated or surrounding plants.
Here’s a very interesting summary of many clinical studies on the chinaberry extract as an organic pesticidal and fungicidal agent. The Potential Uses of Melia Azedarach L. as Pesticidal and Medicinal Plant, Review by Adnan Y. AL-Rubae.
At all times when investigaing or using this plant, it is important to wear gloves, avoid inhaling any direct vapors, and never consume under any conditions, unless your are purposefully looking to consume nuero-toxic diuretic. In other words do not eat, and keep out of reach of pets and children.
One simple recipe for making the chinaberries usable in garden is by letting them soak in one liter of pure alcohol for one week, and later mix 1 part of the chinaberry-alcohol infusion to 3 parts water.
First we will need to remove the branches and leaves from the berries.
We are left with about 2 cups worth of chinaberries.
We drop all of the de-branched berries into the bottom of of a large plastic PET bottle. Then we dump the entire liter of alcohol into the bottle.
The chinaberries should be completely submerged in the alcohol. It is not advised to crush the berries at this stage, because we do not want to inhale toxic vapors. Additionally, after one week of soaking in the alcohol, we will see that a great deal of the characteristic green juice has naturally soaked out of the berries without ever having to crush them.
After soaking for one week (and shaking a few times during the week), the alcohol infusion has absorbed the berries’ green color, as well as their pesticidal content. This mixture is now ready to mix in a spray bottle, one part chinaberry alcohol to 3 parts water. When applying to plants it is recommended to wear a dust mask so as not to breath in the chinaberry vapors.
When applying to garden plants observe over a few days to make sure the plants show no signs of chemical burn. If so, add more water to the mix for further use.