Status Report on Global Neem Usage - Gtz

3. NEEM AS A NON-SYNTHETIC PESTICIDEconditions for at least 1 year. Practical sizes for bags of crushed seeds are 250 g and 2 kg.Their principal use is for water extracts in households and gardens.The press cake is packed and handled in the same way as the crushed seeds. It is useddirectly to control soil-borne pests and as a fertiliser. Normally 30 g per square metre isadded to the soil a few weeks before sowing.The most common way of using neem oil as a pesticide is on the basis of an oil-and-wateremulsion, which needs an appropriate emulsifier. Around the world many different emulsifiersare used. The principal ingredients are various vegetable oils and detergents. It is importantthat additives are properly biodegradable so that the ecological benefits of neem are notcounteracted. Neem oil and the emulsifier have to be mixed in the right proportions to get theideal emulsion in water (the neem oil should not float on the water). Normally the mixture ofoil and emulsifier is used diluted to between 0.5 and 1.0 % in water. The dilution chosendepends on the type of plant: 0.5% is used on plants with soft leaves (e.g. many vegetables);1 % can be used on plants with hard leaves (e.g. many fruit trees and ornamentals). A thirdcomponent can be added: sodium salt, normally known and used as “baking powder”, but atthe same time it is very effective against many phytopathogenic fungi, especially mildew.According to many users, the home-made pesticides are more effective than the formulatedneem-based pesticides. The reason is that in addition to the insecticidal effect, the rawmaterial has strong repellent and feeding-inhibitory effects. On the other hand the raw materialis a plant nutrient and fortifies the plants treated. Formulated neem-based pesticides donot have these advantages. Most of the users of home-made pesticides are hobby gardeners.After a period of time they tend to stop using any other garden additives like fertiliseror pesticides.- Formulated neem-based pesticidesFormulated pesticides can only be made from neem using more advanced technology andknow-how. And yet, such neem-based pesticides no longer pose any considerable or insurmountableproblems from the point of view of production. Manufacture is carried out bylaboratories in small and medium-sized companies in semi-industrial extraction plants (7, 8,30, 31, 34, 37).The most common raw material is dried neem seed. The neem oil is generally pressed outand the resulting press cake is then used to make a pesticide rich in azadirachtin.There are four stages of production:1. Alcoholic extraction2. Alcohol recovery3. Purification and concentration4. Formulation and stabilisation35