Insecticidal Effect of Neem Cake Extracts on Cabbage Pests, Aphis gossypii and Pluetella xylostella

In organic agriculture, choose of effective and cheap bio-pesticide is very important. The authors developed an insecticidal extract from neem cake, waste of neem oil from kernel, and applied as a bio-pesticide. Bio-pesticide neem cake extracts experiment on cabbage pest was carried out at Wonju Agricultural Technology and Extension Center from 11 March to 30 May 2003. There were six treatments with three replications, using completely randomized design. Treatments involved three and six sprays of synthetic pyrethroid pesticide cypermethrin 10 EC at the dilution rate of 2.2 mL $L^{-1}$ of distilled water and four, five and six sprays of bio-pesticide neem at the dilution rate of 13.3 mL $L^{-1}$ of distilled water, and untreated control. For each treatment, designated sprayings were done at 7 days interval. Pre-spray data showed that the plants in all the experimental plots were already infested with aphid (Aphis gossypii), and diamondback moth (Pluetella xylostella). The results indicated that all neem pesticide treatments were more effective in insecticidal activity than the untreated control and the chemical treatments in controlling aphids and diamondback moth. Among the three neem treatments, there were no significant differences between them.