One of the plants used in biological control is nettle (Urtica dioica).

The high in salicylic acid and formic acid makes preparations bite an effective means to combat many plant and animal pests. All formulas are prepared using the Nettle whole plant, without roots in quantities of 1 kg of fresh herb or plant seaca 200 g (dry) per 10 liters of water. 

Maceration of nettle sting is prepared in cold water leaving until the liquid becomes very dark, and no foaming. To speed up the container may be exposed to sunlight. Seaweed meal and a few leaves of Angelica archangelica can be used to neutralize the smell mostly postponed the preparation during fermentation. The drug should be mixed every day, and is ready after 7-10 days. 

Nettle maceration undiluted, it is useful to accelerate maturatiei compost and keep away ants sprinkled on the ground. Diluted with water in 1:20 ratio effective for accelerating growth resulting young plants. The same dilution, spraying three days consecutively every 2 weeks, it is useful against cryptogamic diseases (fungi, disease peaches - Taphrina deformans, vine disease caused by the fungus Plasmopara viticola), many insects (cherry wood fly - Rhagoletis cerasi, Tignola fasciata). Maceration can be used to disinfect the plant roots before transvazarii. 

Nettle maceration should not be used on cabbage family species on vegetables and fruits for preserving the (apple) while treatments on tomatoes and cucumbers should be made only limited field. 

Source www.lifegate.it