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Neem

Common names: Neem, Margosa tree
Scientific name: Azadirachta indica
Family: Meliaceae


picture discription
Photo by Manuel Parami

Plant parts used


Leaves and seeds

Mode of action


Repellent, insecticidal, antibacterial, antifungal, antifeedant, oviposition and growth inhibiting, and crop and grain protectant (Prakash; Rao, 1997: pp. 35-103)

Formulations

r n n n
Materials  Methods of preparation  How to use  Target pests 
Neem leaf extract
(Sridhar; Vijayalakshmi, 2002: pp. 24-25)

1-2 kg of neem leaves
Mortar and pestle
Used cotton cloth
Pot
Soap
Strainer
String


10-12 kg of neem leaves are needed for 0.4 ha




Pound neem leaves gently.
Place in a pot.
Add 2-4 liters of water.
Cover the mouth of the pot securely with the cloth and leave it as such for 3 days.
Strain to get clear extract.




Dilute 1 liter of neem leaf extract with 9 liters of water.
Add 100 ml of soap.
Stir well.
Spray on the infested plants.





Aphids
Colorado beetles
Grasshoppers
Grubs
Japanese beetles
Leafhoppers
Locusts
Planthoppers
Scales
Snails
Thrips
Weevils
Whiteflies

 
Neem seed extract
(Sridhar; Vijayalakshmi, 2002: pp. 24)

3-5 kg of neem seeds
Mortar and pestle
Used cotton cloth
Earthen pot
Soap
Strainer
String




Remove the shells.
Pound seeds gently.
Place in a pot.
Add 10 liters of water.
Cover the mouth of the pot securely with the cloth and leave it as such for 3 days.
Strain to get clear extract.




Dilute 1 liter of this extract with 9 liters of water.
Add 100 ml of soap.
Stir well.
Spray on the infested plants.





Aphids
Beetles
Bugs
Grasshoppers
Grubs
Flies
Leafhoppers
Locusts
Moths
Nematodes
Planthoppers
Scales
Snails
Thrips
Weevils
Whiteflies

 
Neem seed powder extract (Singh; Singh, 2000: pp. 5-7)

Matured, dried neem seeds
Mortar and pestle
Basin, pail
Muslin pouch
Strainer
Soap (5 ml/10 l of water)
Water





Remove shells and pulps from seeds in the desired amount. Then pound seeds gently in such a way that no oil comes out.
Once done, put the desired amount of powder in a pail of water.
Stir well for about 10 minutes and steep for at least 6 hours but not more than 16 hrs. Stir it again for another 10 minutes.
Strain.
Add soap. Stir well.




Refer to Table 1 for the neem powder and water ratio for the control of specific pest


Spray on the infested plants thoroughly.
Spray early in the morning or late afternoon.




Cotton bollworm
Aphids
Colorado beetles
Cotton leaf roller
Cutworm
Diamondback moth
Fall armyworm
Grasshopper
Japanese beetles
Leaf miner
Leaf hopper
Locust
Mexican bean beetle
nWhiteflies

Neem seed oil suspension in water
(Singh; Singh, 2000: pp. 5-7)

5 kg of finely ground neem seeds
1/2 liter of hot water
Soap
Basin





Put the finely ground seeds into a basin.
Add hot water little by little until it is possible to knead the mixture.
Knead and press the mixture to get the oil.

Approximately 650-750 ml oil is extracted from this mixture.






Refer to Table 2 for the oil and water ratio

Take desired amount of neem oil and mix with soap before adding water. Stir thoroughly to prevent oil separation.

Fill-in the knapsack sprayer.
Spray thoroughly on infested plants.





Aphids
Brown planthopper
Flea beetle
r Leafhopper
Potato tuber moth
Psyllid
Scale insects
Whitefly
Whorl maggot

 

Neem as prophylactic

1. Pound neem leaves or seeds or neem cake. Put it in a clay pot. Add twice the volume of water, then cover securely the opening of the pot. Let it stand for 3 nights.

To use, divide the filtrate into 4 (or more) and put these separately in opened containers. Place containers in strategic areas in the field at night time to repel nocturnal pests. The smell repels the insects from coming into the field.

2. Fill in jute sacks with neem cake. Place the sacks along the water canals. The dissolved neem cake carried into the field prevents the attack of pests and diseases affecting the roots and tillers.

Notes:

1. Neem seed extract should be milky white in color and not brownish. If pounded with the seed coat on, 1 ½ times the amount of seeds are required.

2. It is very important to add the soap with the oil before adding water. It should be used immediately otherwise oil droplets will start floating. A knapsack sprayer is better for neem oil spraying because it has the tendency to mix the extract while in the process of spraying.

3. The 3 extract formulations can also be used for fungal diseases control including those that are soilborne. Neem cake can be used as soil manure- to improve the soil condition and to control various species of nematodes.



Table 1. Recommended powdered kernels and water ratio for various pests
(Singh; Singh, 2000: pp. 5-7)

n r

Pests

Powdered kernels in grams (g) per liter (l) of water

Powdered kernels in kilograms (kg) per 600 liters (l) of water per hectare (ha)

Dessert locust

5

3

Hairy caterpillar

Giant looper

Gypsy moth

Migratory locust

10

6

Leaf miners

15

9

Cabbage aphid

Cutworm

Japanese beetle

20

12

Chafer beetle

Colorado potato beetle

Flea beetle

30

18

Corn earworm

40

24

American bollworm

Aphids

Cotton leaf roller Diamondback moth

Grasshopper

Leaf hopper

Leaf miner

Red locust

Mexican bean beetle

Mustard aphid

Whiteflies

50

30

Fall armyworm

60

36

Pod fly

80

48

Citrus leafminer

100

60



Table 2. Recommended neem oil in water suspension for various pests
(Singh; Singh, 2000: pp. 5-7)

Pests

Neem oil in milliliter (ml) per liter water

Neem oil in liter (l) per 600 liters (l) of water per hectare (ha)

Potato tuber moth

Red and yellow scales

Tortoise beetle

10

6

Psyllid

Whitefly

15

9

Midge

Whorl maggot

20

12

Cotton aphids

Flea beetle

Gall midge

Leafhopper

30

18

Brown planthopper

100

n

60



Precaution: Oil maybe phytotoxic at a ratio of 10 ml oil/liter of water on sensitive plants. Wait for 2 days for the effects (symptoms) to appear before going into large scale application.

Standard procedures for the preparation and application of the plant extracts

  1. Select plant parts that are free from diseases.
  2. When storing the plant parts for future usage, make sure that they are properly dried and are stored in an airy container (never use plastic container), away from direct sunlight and moisture. Make sure that they are free from molds before using them.
  3. Use utensils for the extract preparation that are not use for your food preparation and for drinking and cooking water containers. Clean properly all the utensils every time after using them.
  4. Do not have a direct contact with the crude extract while in the process of the preparation and during the application.
  5. Make sure that you place the plant extract out of reach of children and house pets while leaving it overnight.
  6. Harvest all the mature and ripe fruits before extract application.
  7. Always test the plant extract formulation on a few infested plants first before going into large scale spraying. When adding soap as an emulsifier, use a potash-based one.
  8. Wear protective clothing while applying the extract.
  9. Wash your hands after handling the plant extract.

Effect on humans

None; the proper use of neem has not been associated with any side effects.


Effect on non-target organisms

Azadirachtin is relatively harmless to butterflies, bees, ladybugs, and wasps since these beneficials feed on nectar and pollen. Azadirachtin must be ingested to be effective so that pests which feed on plants are affected by its content. However, constant spraying of flowering plants with highly concentrated neem products affect bees since they carry contaminated pollen and nectar to the hives (National Research Council, 1992).


A study was conducted on neem products and their effects on mortality, growth, and reproduction of 7 species of earthworms. Various neem products were incorporated in the upper 10cm soil layer of tomato plots. None of the materials had negative side effects on earthworms. Positive effects on weight and survival were found in soil treated with ground neem leaves and ground seed kernels under greenhouse conditions. Reproduction was slightly favored over a period of 13 weeks in a neem-enriched substrate in rearing cages (Rossner; Zebitz, 1986: pp. 627-632).


Azadirachtin has no side effects on birds and other animals (Martineau, 1994). There is no toxic residue left to contaminate the environment and insects do not develop resistance to neem (Prakash; Rao, 1997: pp. 35-103).



External links


References


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