Field Testing of Efficacy of Three Environmentally Friendly Insecticides Against Colorado Potato Beetle (Leptinotarsa Decemlineata [Say], Coleoptera, Chrysomelidae) on Potato-Evaluation of the Effect on Yield

摘要

In 2007 and 2008 the field experiment was conducted to test the efficacy of three environmentally friendly insecticides against the Colorado potato beetle ( Leptinotarsa decemlineata ), with the aim of evaluating their effect on the yield of potato. 0.25 % water emulsion of Neem-Azal (active ingredient azadirachtin) was applied twice, while 3 % water emulsion of Aktiv (a.i. potassium salt of fatty acids) and 1 % water emulsion of Prima (a.i. refined rape oil) were applied eight times. In 2007, the potato yield was higher (25.3±3.2 t ha -1 ) than in 2008 (8.2 ± 0.8 t ha -1 ). In 2007 there were no significant differences in potato yield at different control measures and the yield ranged from 7.5 ± 1.3 t ha -1 (Aktiv) to 9.4 ± 1.8 t ha -1 (Prima). In 2008, the highest potato yield was recorded in Neem-Azal treatment (3.5 ± 0.7 t ha -1 ), while in two other insecticide treatments the potato yield did not differ significantly with control treatment neither with the Neem-Azal treatment. Potato tubers were classified into three fractions: fraction 1 (tubers 5 cm). On average we produce 2.11 ± 0.06 t ha -1 , 9.93 ± 0.53 t ha -1 , and 13.17 ± 0.70 t ha -1 of potato in 2007, and 2.11 ± 0.20 t ha -1 , 4.68 ± 0.37 t ha -1 , 0.84 ± 0.29 t ha -1 of potato in 2008, respectivelly.