Gabriele Stoll
Natural Crop Protection in the Tropics
Letting Information Come to Life
Methods of Field Protection
Insect-controlling plants

Sweetsop (Annona squamosa)  
Soursop  (Annona muricata)
Custard apple (Annona reticulata)

Fam. Annonaceae

More than 90 species of small trees and shrubs are known in the Annonaceae family. They occur mostly in tropical America, but some are also found in Asia and Africa. Soursop and custard apple are widely distributed in Central America and the Caribbean, while sweetsop is commonest in India and Southeast Asia. They do not require special conditions of soil or water, but thrive best in places where there is a clear division between the rainy and dry season, and generally prefer dry sites. The effective ingredients are found in the unripe fruit, and in the seeds, leaves and roots. The oil content of the seeds amounts to 42–45%. On ordinary soils, the yield ranges from 50 to 100 fruits per tree, in fertile soils it may reach up to 500. A well maintained orchard can be economical for 15–20 years.

Plant parts with insect-controlling properties
Seeds, leaves, unripe fruits

Mode of action
Contact and stomach poison
Ovicidal, insecticidal, repellent, antifeedant, antinematode/nematocidal

Target pests
Field insects
Brown rice planthopper
Chrysanthemum aphid
Coffeegreen scale  
Cotton stainer  
Diamondback moth    
Green bugs  
Green rice leafhopper  
Mediterranean fruitfly    
Oriental fruitfly  
Potato aphid  
Red pumpkin beetle  
Southern armyworm  
White-backed rice planthopper
Nilaparvata lugens
Macrosiphoniella sanborni
Coccus viridis
Dysdercus koenigii
Plutella xylostella
Nephotettix virescens
Ceratitis capitata
Bactrocera dorsalis
Macrosiphum euphorbiae
Aulacophora foveicollis
Spodoptera eridania
Sogatella furcifera
Side effects on humans
When handling the seeds of Annona, care should be taken to ensure that the powder does not come into contact with the eyes, as this causes painful irritations.
Special characteristics
The seeds are much more toxic than the leaves.

Methods of preparation and use

Custard apple leaf extract
500 g of custard apple leaves are boiled in 1–2 litres of water. Allow to boil down to ca. 1/4 of the original liquid. Strain this liquid and mix it with 10–15 litres of water. This is ready to be sprayed over the crop. For one hectare, 5–7.5 kg of fresh leaves are required.

Custard apple – calotropis – tobacco extract
Take 500 grams of custard apple leaves and boil in 1–2 litres of water. Allow to boil until it becomes thick. Filter the solution to receive the decoction. Take 250 to 300 ml of calotropis extract made from the leaves. Take 500 g of tobacco leaves and boil in 1–2 litres of water for ca. 45 minutes. Then filter the extract and add 250 ml of biogas waste (whitish fluid which deposits in the biogas digester) and 100 g of copper sulphate. Mix the above ingredients with 60 litres of water and spray over the crop. The above quantity is recommended for 0.4 ha.

Custard apple – neem – chilli extract
Take 2 kg of custard apple leaves and grind them well. Add 500 ml of water and stir. Filter to get the extract. The filtrate is kept aside. Take 500 g of dried chillies and soak them in water overnight. Next day, grind and filter the solution to get the extract. Take 1 kg of crushed neem fruits and soak in 2 litres of water overnight. Then filter the extract. Mix all the three filtrates with 50–60 litres of water. Filter again and spray over the crops.

Custard apple seed extract
Use this solution to spray plants infested with aphids or ants. Crush seeds of custard apple and mix them with water at a rate of 40 g per litre. From Thailand farmers reported that they prepare a spray made of 500 g finely ground seeds which are soaked in 20 litres of water for 1–2 days. After filtering it is ready to be sprayed. This spray is claimed to be highly effective.

Other uses of plant or substance
• Leaves are medicinal for a number of ailments.
• Fresh flowers are eaten as food. The wood is not attacked by white ants. In India it is often used for carts and house construction.