A more nuanced method to control pest in farming, in urban context and otherwise, is the augmented use of EM Solution. Effective Microorganism (EM) solution – available in the market for NRs. 100 (USD 1.25) per litre – contains several bacterias such as photosynthetic bacteria, lactic acid bacteria, yeast, and other microorganism.
For the EM insect repellant, I used the following combination mix*:
EM Solution 500 ml
Whisky 500 ml (alcohol content)
Molasses 500 grams = 1.1 pounds
Warm Water 3 liters
Dried Nepali Hog Plum 500 grams (acetic acid content)
Total 5 liters
The basic idea for the combination mix was taken from the standard EM Insect Repellant mix, which is elaborated here by the Garden City Composting team in Christchurch, New Zealand.
I bought old whisky, sugar molasses (sakkhar), and dried nepali hog plum from a general store around the block. Just to clarify, bacterias produce alcohol, and subsequently, sour vinegar when they ferment sugar molasses; whisky and dried nepali hog plum (lapsi) were just added – I assume – to catalyze the fermentation. Warm water also helps the fermentation by increasing the base temperature. Further iterations of the solution mix will attempt addition/removal of components to locate the exact utility for each component.
The resultant 5 liters of EM insect repellant mix was mixed thoroughly, and then put in five one liter reused drinking water bottles. The solution will be kept at a temperature range of 15 – 25 degree Celsius. Most importantly, the lids of the bottles are opened for 30 seconds each, two times a day. This is crucial as the undergoing fermentation is an aerobic process, and opening the lids allow the release of built up carbon dioxide and lets in the required oxygen. The resultant mix should be ready for use in 2-3 weeks when a sweet fruity odor is observed.
Based on internet research, I found that one can also add ginger, garlic, pepper, and other food items that have strong bitter, hot, and sour taste. One can just ground these food items and drop them into the mix.
Over the last week, I have observed that there is a tremendous effervescence of carbon dioxide each time the lids are opened. The effervescence is comparatively quite weak in the control experiment, where the solution does not have whisky and dried hog plum. This seems to corroborate the hypothesis that addition of alcohol (whisky) and acetic acid (Nepali hog plum) increases the rate of fermentation.