Effect of gibberellic acid on population growth parameters of cabbage aphid (Brevicoryne brassicae L.) on the cabbage (Brassica oleracea L.)

Due to environmental pollution caused by chemical pesticide application, the use of eco-friendly methods such as induced resistance to manage insect pests is necessary. In this study, the induced resistance potential of gibberellic acid, with a concentration of 0.125 g/L, in cabbage was investigated against cabbage aphid Brevicoryne brassicae L. Population growth parameters of cabbage aphid, including intrinsic population growth rate (r), net reproduction rate (R0), finite population growth rate (λ), gross reproduction rate (GRR), and population doubling time (DT) affected by gibberellic acid were significantly reduced compared to the control group (P < 0.05). However, there was not any significant difference between gibberellic acid treatment and the control for mean generation time (T) and the mean fecundity per adult female. The mortality rate of nymphs and adult females, age-specific survival rate (lx), and age-specific fertility (mx) in gibberellic acid treatment were significantly decreased compared to the control (P < 0.05). The mortality rate of first-stage nymphs was higher than the control and other stages. The dispersal percentage of first-stage nymphs and adult females treated with gibberellic acid was increased compared to the control (P < 0.05). Based on the results of this study, gibberellic acid was effective for decreasing the population growth parameters of cabbage aphid, and it can be considered in the integrated management of the pest.