Avaliação da eficácia da combinação de diferentes grupos de insecticidas no controlo da traça da couve (Plutella xylostella L.) na cultura de repolho

Abstract

The crucifer moth, Plutella xylostella L., is the main pest of brassicas worldwide. The great capacity to develop resistance to insecticides and the occurrence in high population densities has made the economic production of brassicas practically impossible in certain regions. In this context, the adoption of forms of insecticide combinations for its control is important for the elaboration of an integrated management plan for the species. For this purpose, an experiment was carried out at the Agraria do Umbelúzi Station, district of Boane, Maputo province, to test the combination of different insecticides, applied by calendar at 15, 30, 45 and 60 DDT in four cabbage varieties (Pruktor, Escazu , Gloria F1 and Gloria of Enkhuizen). The design used was Randomized Complete Blocks (DBCC), with ten treatments and three repetitions. Each plot was formed by three lines with twelve plants totaling thirty-six. The variables measured were population density (SD),% of Infestation (PI), average attack level (NMA), yield, numbers of commercial and non-commercial heads and gross margin. The data were processed in the GenStat IV statistical package and ANOVA was performed at a significance level of 5%. In accordance with the results, it was observed that the combinations of Lambda Cialotrina (LC) + Indoxacarb, LC + Lufenuron and LC + Metamidophos significantly reduced the population density,% of infestation and average attack level from 30, 45 and 60 DDT, resulting in higher commercial yield and gross margin compared to other treatments. (TRADUÇÃO NOSSA)