By Mrs. Farzana Panhwar – There is demand the world over for pesticide-free food, but the information on various natural pesticides for garden use is lacking. Therefore, these methods are little used in Pakistan and other developing countries.
Neem is known to work for the control of many insects, pests, fungi, nematodes and viral diseases, but it is used in a very primitive manner and impractical process, except on a small scale for kitchen gardens or plots of less than an acre. A solution has to be found for its commercial applications and extraction on a much larger scale.
Many fruits and vegetable crops have insect- and disease-controlling properties in their seeds, leaves, stalks, unripe fruit, bulbs, rhizomes, etc. Examples are: custard apple (Annona reticulate), basil (Sweet Basil) and Holy Basil, chilies (Capsicum frutes), (Fam. Sollanacea), garlic (Allium Sativum) (F. Lilacae), ginger (Zingber officiate) (fm. Zingiberatase), neem, papaya (Carcia papaya), tobacco (Nictana tabacum, Nicotana, Rustica) and nicotana glutnosa (Fam. Ziberacease).
Each plant part controls different pests including caterpillars, green bugs, fruit flies, leaf minors, red spiders, ants, slugs, house flies, mites, white flies, bacteria, scab, bowl-worm, thrips, anthracnose, hoppers, scales, termites, thrips, mosaic virus, powdery mildew and aphids control.
Plants that serve as natural pesticides for garden use should possess the following characteristics:
• Be effective at the rate of 3-5% plant material based on dry weight
• Be easy to grow and require little space and time for cultivation and procurement
• Be perennial
• Recover quickly after the material is harvested
• Not become a weed or hose to plant pathogens or insect pests
• Possess complementary economic uses
• Pose no hazard to non-target organisms, wild life, humans or the environment
• Be easy to harvest
• Preparation should be simple, not too time consuming or requiring too high a technical input
• Application should not be phytotoxic or decrease the quality of the crop, e.g., taste or texture
(Metric/U.S. conversions: 1 hectare = 2.471 acres; 1 liter = o.o567 U.S. quarts; 1 adoirdupois lb. = 0.45359 kg.)
• Soursop. Custard apple (Annona reticulata). Plant parts with insect-controlling properties are seeds, leaves, and unripe fruit. It disrupts feeding and acts as an ovicide, insecticide, repellent, and repels nematodes. Target pests are aphids, caterpillars, green bugs and Mediterranean fruit flies. It is prepared by boiling 500 grams of custard apple leaves in 2-1/2 liters of water, until only one-quarter of the original is left, then dilute this mixture in 15-20 liters of water. This is enough to cover one hectare.
• Basil. Sweet Basil (Ocimum basilium), Holy Basil (Ocimum Sanctum). Plant parts with insect-controlling properties are leaves and stems. They act as a repellent, insecticide, and fungicide and molluscicide. Target pests are fruit flies, leaf miners, red spiders and mites. Prepare the natural pesticide by soaking 100g of basil leaves in 1 liter of water soaked overnight. Filter the mixture and add 1ml of liquid soap. Stir. Dilute into 10-15 liters of water. Learn more about growing basil in your garden.
• Chilies. The fruit contains the insect-controlling properties. The mode of action is on the stomach where it disrupts feeding. It acts as an insecticide. Repellent, and fumigant. Its target pests are ants, aphids, caterpillars and slugs. It is prepared by soaking 500g of chilies in three liters of water for 10-15 minutes. Add 30g of soap. Add three more liters of water, filter, and spray the plants. You could add garlic, onion, citruc, alcohol, neem or lime.
• Garlic. Allium Sativum (Fam. Lilaceqe). The bulbs of the garlic plant contain the insect-controlling properties. The mode of action is as an insecticide, repellent, fungicide, disrupts feeding, and nematocide. Its target pests are aphids, house flies, mites, white fly, bacteria, cucumber beetles, ticks and scab. It is prepared by finely grinding three bulbs of garlic, add some kerosene, keep it for two days, then add one tablespoon of soap powder, stir, filter, and add 15-20 liters of water. (Garlic can also be mixed with chilies.) Learn more about growing garlic in your garden.
• Ginger. Zingber officiale (Fam. Zingiberacae). The rhizomes (roots) of the ginger plant contain the insect controlling properties. The mode of action is as a repellent, insecticide, nematocide and fungivide. Its target pests are American boll worms, aphids, thrips, white flies, and mango anthracvose. It is prepared by crushing 500g of garlic, add 10 ml of kerosene oil, and let sit overnight. The next day remove the outer skin of the ginger and make a past from the root. In another container, add 100g green chilies mixed with 50ml of water and add 30g of liquid soap as an emulsifier. Stir the solution and filter. Add 10-15 ml of water (you could add ginger and chilies, too).
• Neem. The seeds and leaves of the neem plant control insects and disease. (The neem plant is native to India.) The mode of action is as an insecticide, repellent, growth inhibitor, nematocide, fungicide, and antiviral action. Neem compounds act mainly as a stomach poison and are systemic. Its target pests are American boll-worms, ants, locusts, leaf hoppers, leaf miners, mites, scales, termites, thrips, and white flies. It is prepared by soaking 1 kg of neem leaves in two liters of water overnight. Boil it 15-20 minutes until only ¼ is left. Dilute it with 10-15 ml of water.
• Papaya. Garcia papaya. Plant parts with insect controlling properties are the leaves, seeds, and unripe fruit. Its target pests are mosaic virus and powdery mildew. It is prepared by finally shredding 1kg of leaves, soaked in 1 liter of water, and squeezed through a cloth. Take one liter of soap solution and dilute it in 10-15 ml water.
• Tobacco. Nicotana tabacum, Nicotana Rustica, Nicotana glutnosa, and Fam. Solanaceae. Plant parts with insect controlling properties are the leaves and stalk. It’s mode of action as an insecticide, repellent, fungicide acaricidal contact, and it affects the stomach. Its target pests are aphids, caterpillars, leaf miners, mites and thrips. It is prepared by boiling four liters of water, with ½ kg of tobacco leaves, and one tablespoon of lime. Dilute it with 10-15 liters of water.
(Editors Note: The use of tobacco is no longer recommended due to health complications in mammals. Nicotine is highly toxic and remains on leaf survfaces for several weeks after application. It may also cause tobacco mosaic virus on eggplants, peppers, tomatoes, potatoes and related plants.)
• Tumeric. Curcum domstica (Fam. Zigiberaceoe). Plant parts with insect controlling properties are rhizomes. It acts as a repellent and insecticide and has antifungal properties. Its target pests are aphids, caterpillars, mites and rice leafe hoppers. It is prepared by chopping and soaking 500g of turmeric rhizomes overnight. Dilute into tow liters of water and again, dilute into 10-15 ml of water.
Here is another — yucky but natural — way to reduce pest populations. (We recommend trying this on an empty stomach.)
Bug juice: Collect ½ cup of your specific pest and mash well. Mix with 2 cups of water and strain. Mix ¼ cup of this juice with a few drops of soap and 2 cups of water. Spray whatever plant the former pests were attaching (Don’t use food-grade dishes or utensils for this one!)
Good luck using these natural pesticides for garden use.
Originally published in Countryside May/June 2004 and regularly vetted for accuracy.