July 2012. A member from Vanuatu wrote asking about pesticide formulations made from the following, which are being tested in the country. A request was made for references and also experimental procedures to test the various concoctions.
- Ginger rhyzome
- GliricidialLeaf
- Onion bulb
- Garlic bulb
- Papaya leaf
- Liquid soaps
- Hot pepper infusions
- Baking soda
‘Chilli-garlic’ – is commonly used as an insecticide in South India and perhaps elsewhere in South Asia. The chilli and garlic are mashed up – and applied in a suspension – a decoction. Ginger was also added by some proponents. Processing the garlic is not too bad but I remember that mashing the chilli (hot chilli from Guntur) was not a popular job – it was usually left to female labourers!
The ‘decoction’ was applied to cotton and pigeonpea to ‘manage’ Helicoverpa armigera, in particular. But there seem to be no reports of controlled experiments that provide an indication of the how effective this method might be. Standardising the rate and the varieties would be a problem! It is assumed that it has a repellent or antifeedant mode of action. It is unlikely to be any ‘kinder’ to beneficial species than to the pests. I wonder: if the chilli seeds have insecticidal properties (if dried and crushed) – how about mixing the mashed vegetables with a vegetable or mineral oil + a detergent or soap (remembering the the oil, detergents and soap (also on your list) have potentially insecticidal properties).
Another member from El Salvador, reported success with 2 large onions, preferably red, plus 2 garlic bulbs and 300 g chilli. Mash, and add a gallon (4.5 litres) of boiling water, cool, filter and used at 10 ml per litre water.
PNG reported some work with chilli and neem, and that it was quite effective on green leafy vegetables.
Equipment needed:
- 1 medium size plastic bucket (~10L), rubber gloves, wooden hammer/strong stick, plastic kitchen strainer, stick for straining, sprayer, clean water (preferably rain water), piece of washing soap, chilli pods — 350g fresh or 70g dry pods (about a handful).
Making Chilli extract ~ PDP
- Put chilli pods into bucket
- With a mallet or gloved hand pound or squeeze pods to a fine paste
- Add one litre water (3 coke cans) and rub mixture of pods and water between gloved hands
- Add four teaspoons (20g) of soap flakes
- Stir and leave mixture in bucket overnight or for one day
- Pour liquid into sprayer through a strainer to remove dirt and large particles
- Add water to make up to the knapsack carrying capacity
- The liquid is now ready to spray the crops
Members were also reminded of the fact sheets that have been done for Solomon Islands and these on the PestNet website (staging.pestnet.org).
From Fiji, a paper on the use of kava against root-knot nematodes.
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