Consórcio de brócolis com funcho visando o controle biológico de pulgão

Abstract

Population disturbances of phytophagous arthropods are common in simplified agroecosystems, making it necessary to develop more sustainable alternatives. Conservative biological control is an important tool for the ecological management of pests, through productive redesign that promotes attraction and maintenance of natural enemies. The objective of this work was to evaluate the efficiency of inter-cropping branch broccoli with fennel, in the presence or absence of weeds, in the conservative biological control of aphid populations. The experiment was carried out during two broccoli cycles, the first from December 2021 to March 2022 and the sec-ond from the end of March to July 2022. The design was randomized blocks, with four replications and three treatments: single cultivation of branched broccoli (B) (control); intercropping of branchy broccoli with fennel (BF) and intercropping of branchy broccoli with fennel with the presence of spontaneous plants (BFsc), all conducted with organic fertilization and the weeding carried out by hand. For broc-coli, the following were evaluated: infestation index in the plot; infestation intensity index in leaves, branches and inflorescences; and the population density of aphids. For fennel, the index of aphid infestation in the inflorescences and the total count of adults, eggs and larvae of ladybirds and syrphids seen per fennel plant were evalu-ated. The productivity of broccoli and fennel was also evaluated. The consortium of broccoli and fennel with the presence of spontaneous plants, had a lower number of plants infested by aphids and less aphid infestation on the branches, however, a reduction in the productivity of broccoli (second cycle) and fennel was observed. The consortium with weeding showed broccoli productivity equal to that of single cultivation, with an increase with fennel production and a reduction in the popula-tion density of aphids on medium leaves. The consortium with weeding was viable, diversifying production, but with little influence on conservative biological control. The presence of spontaneous plants, despite their influence on biological control, must be applied with reservations.