Fam. Ammonaceae
More than 90 species of small tree and shrubs are known in the Annonaceae family. They occur mostly in Tropical america, but some are found also in Asia and Africa. Soursop and custard apple are widely distributed in Central America and the Carribbean, while the sweetsop is commenest in India and Southeast Asia. They do not require special conditions of soil or water, but thrive best in places where ther is a clear division between the rainy and the dry season, and generally prefer dry sites in wich to grow.
The effective ingredients are in the unripe fruit, and in the seeds , leaves and roots. The oil content of the seeds amounts to 42-45 %.
Contat – and stomac poison
Insecticidal , larvicidal , repellent , antifeedant.
Aphids - general
Brown rice plant hopper - Nilaparvata lugens
Diamondback Moth - Plutella xylostella
Chrysanthemum aphid - Macrosiphoniella sanborni
Grasshopper - general
Green bugs - general
Green rice leaf hopper - nephotettix virescens
Potato aphid - Macrosiphum euphorbiae
Red pumpkin beetle - Aulacophora foveicollis
Whitebacked rice plante hopper – sogatella furcifera
Annona has not proved effective against the
Saw-toothed grain beetle Oryzephilus surinamensis
Trouver une photo de Sweetop (annona squamosa)
The toxic effect of Annona sets in slowly , 2-3 days should be allowed.
Laboratory trials have shown that by extracting annona seeds with ether or petroleum ether, the toxicity can be increased 50-100 times. But since laboratory methods are impractical in the field, other locally availabe and cheap solvents could be tried, like petrol or kerosene.
When pulverising the seeds of A. squamosa , care should be taken to ensure that the powder does not come in contact with the eyes as this causes great pain.
The custard apple is the most effective of annonas against insects.
Relatively little information exists on the preparation and use of annona. Wide-ranging laboratory trials have demonstrated its higly effective insecticidal values. Experimentally-inclined farmers could contribute much needed information about widely distributed plant.
A 10 % concentration of seed oil produces a 90 % death rate of the bug Urnetius echinus within 72 hours. A 5-7 % concentration is still effective, but low concentration of 1 – 3 % produce no results.
Pulverised seeds are used in China and the Philippines against Lecanium in West Africa. The writers gives no details regarding quantities.
An extract of the leaves with ether proves higly successful against the red pumpkinn beetle (Aulacophora foveicollis). A diluted solution achieves a 91 % rate .
Fam. Solanaceae
Chillies are widely distributed in the tropics and subtropics and originate in South America where they were early cultivated. They were introduced to the rest of the world by the Spaniards and the Portuguese. The ripe fruit has insecticidal properties and the effective substances are highest in the skin and in the seeds ;
Stomac poison
Insecticidal repellent , antifeedant , fumigant , viroid.
Trouver une photo de chili (Capsicum frutescens)
Ants - general
Aphids - general
Caterpillars - general
Colorado beetle - Leptinotarsa decemlineata
Imported cabbage worm - Pieris rapae
Rice Weevil - Sitophilus
Warehouse pests - general
Cucumber mosaic virus - Pieris rapae
Cucumber ringspot virus - Pieris rapae
Tobacco etch - Pieris rapae
Tobacco mosaic virus - Pieris rapae
Tobacco mosaic virus - Pieris rapae
From kenya good results are reported o n the control of aphids in home vegetable gardens.
Hot chillippers are finely ground, stirred in water and allowed to stand overnight. After filtering through a cloth the solution is sprayed onto the plants , or if no syringe is available sprinkled with a whisk of twigs or grass.
A similar method is reported from Papua New Guinea where chilipepper is used as repellent
Finally ground chillies are covered with water and soap either as flakes or liquid. The mixture is well stirred and sprayed over affected plants.
Chilli spray preparation are also well knonw in the philippines :
100 g chillies, water, soap solution :
The chillies are finely pulvrised in a mortar, vigourosly shaken with 1 litre of water and filtered through a cloth. One part of ths concentrate is diluted with five parts of soapy water before spraying. It is effective against aphids and many other vegetable pests.
Too strong a concentrate causes burning of the leaves, so the right strengh should be found by testing.
Care should be taken because the solution irritates the skin.
MCKEEN reports that the young leaves of cowpea were rubbed with virus-infected sap expressed from chilli leaves the colour change was markedly reduced. Mostly there was even none. (The change of colour is regarded as an indicator of a virus infrection). When the experiment was repeated wuth the sap from virus-infected tobacco leaves the cowpea leaves underwent a strong colour change, but when the tobacco sap was mixed with 5 % of chilli sap the number of leaves which changed colour was reduces by 95 %.
The efectivness of the virus inhibition depends on the host plant. It is probable that members of the same plant familly do not work infallibly on one another virus inhibitors. Further tests showed that the virus-inhibiting ingredients is present in all parts og the chilli plant. However, extracts from the leaves and flowers showed the highest concentration and the roots are lowest.
In practise, it is important that chilli sap should be applied as a preventive measure before the virus infection affects the plant. Once the virus has taken hold it cannot be effectively controlled.
This is information is all derived from scientific sources. The writer has no results taken from practice in the field.
Family Leguminoseae
Derris is a small shrub originating in the tropical rainforests of the Malay Archipeligo. It grows in lowland areas and does not thrive at higher altitudes. It is the roots which contain the active substances, mainly rotenone. Grown in the shade D. malaccensis requires a period of 1 1/2 – 2 years for it to produce a worthwhile content of rotenone , but when grown i nfull sunlight needs only nine months for the roots to develop sufficiently.
Deris elliptica developped after 26 months the maximum amount of rotenone. Derris can propagated vegetavitely from 50 cm long cuttings when rooting follows after six weeks. The crop is harvested by exposing the shallow roots and cutting off those with a diameter of 2- 6 cm since these have the highest rotenone content. Derris thrives on many soils but particularly on loams and clays
Contact – and stomac poison
Insecticidal and repellent.
Trouver une photo de Derris ( D. elliptica )
Adzuki bean beetle - Callosobruchus chinensis
Army worms - Spodoptera litura
American bollworm - Heliothis armigera
Diamondback moth - Plutella xylostella
Fruit flies - Dacus spp.
Mediterranean fruit fly - Ceratitis capitata
Melon aphid - Aphis gossypii
- Crocidolomia binotalis
- Margaronia indica
- Crysodeixes chalsites
Derris is also effective against the fungus Pyricularia oryzae.
Derry is most effective against larvae in the young stages. Caterpillars, aphids and beetles are very vulnerable, but it is not effective against cockroaches.
Derris is affected by sunlight , oxygen and temperature. After a week in strong sunlight deris dust is no longer effective. In the shade it retains its properties for a fortnight.
Handling derris dust can also cause skin rashes and should therefore be avoided. If derris dust or spray is inhaled over a period it can give rise to a numb feeling in the lips and tongue and throat.