Tuesday

Organic Insecticides/ Pesticides

In my last article I presented a case against using chemical insecticides, pesticides, herbicides etc... So now the question arises as to what organic methods can be used to control these problems. Every gardener/farmer has to deal with some or the other pests and weeds, there is no escape from that. But there are ways to deal with these problems without causing harm to ourselves or to our planet.
Here I will give you a list of organic insecticides available in the market or may be prepared at home. I do not have any particular brand as my choice, so you can pick any brand but just ensure that it says it is organic and check the list of ingredients. Also follow the exact directions suggested on the label. Most insecticides should be sprayed in the relative cool temperatures of early morning or late evening.
Commercial Methods:
  • Horticultural oil- This is a refined petroleum oil which is sprayed onto the leaves. It suffocates the insects and is relatively less toxic to humans or animals. Can cause plant leaves to burn if applied inappropriately.
  • Insecticidal Soap- One of the safest pesticides which can also be used on vegetables. These soaps are made of Sodium (Na) or Potassium (K) salts of fatty acids. When they come in contact with an insect, they cause the outer covering to collapse, for this reason, the insecticidal soaps are not effective once dried. They can cause plant burn if applied in excess or during hot afternoons.
  • BT (Bacillus thuringiensis)- This is a bacteria which is sprinkled on a plant. When the insects eat this powder, the BT toxin is produced by the bacteria in their stomach and causes the insect to die. Although safe for humans and animals, this is a very slow acting medium and hence may not be always desirable. Also it sometimes causes irritation.
  • Neem- This is derived from the seed of the neem tree fruit. It is sprayed on to leaves and is considered to be safest for humans. It stops the insect from maturing to adult stage, thereby preventing further insect damage. Neem should be applied during the evening hours for maximum benefit and to prevent the active ingredients from degenerating.
  • Pyrethrins- It is derived from Chrysanthemum cinerariifolium and is either available as a powder or in solution. This is fast acting insecticide which acts by poisoning the insects. It may also kill beneficial insects.
  • Potassium bicarbonate- Prevents fungal growth and can be used as a preventive method. It can remain effective for longer periods (2-3 weeks) but can also cause plant burn if applied in excess or during hot spells.

Home-made methods: Use on a weekly basis.

  1. Soap spray- Use 2 tbsp of dish detergent in a gallon of water and spray on to plants. Do not spray too much or else you might harm the plants.
  2. Salt spray- Use 2 tbsp common salt in a gallon of water on plants.
  3. Garlic spray- Finely chop or mince a garlic bulb and add to a gallon of water. Add finely chopped 15 hot chilli peppers or Jalapeno peppers to this mixture. Let sit for a day, strain and spray on to plants. This spray can be stored in refrigerator for 1-2 weeks.
  4. Garlic and mint spray- Finely chop 1 garlic buld, 15 hot peppers (red or green chilli), 1 cup fresh spearmint and add to a gallon of water. Stand for a day and strain. If needed store in refrigerator for upto 2 weeks. Add 2 tbsp liquid detergent and spray on plants. This is wide range insect repellant.
  5. Turmeric can be added to any of this sprays to further enhance the bug repellant properties.

If you know of any other organic methods which work, please let me know. Your suggestions will help other organic gardeners or farmers too.

1 comment:

marye said...

thanks for the ideas! I find that the hot pepper spray works the best for me...you can also use diatamacious earth (not the swimming pool type) to kill soft bodied things..and fleas..just sprinkle it around the plants...beer in a saucer or can really does kill slugs...
Companion planting helps too..Marigolds repel alot of insects...and fresh basil keeps flies away from your door if you plant it in a pot near the door.