Consórcio de milho (Zea mays) com diferentes espécies de cobertura e seletividade da Urochloa brizantha a atrazina

Abstract

Intercropping systems combining main crop together with plants that are beneficial to the system is becoming a reality in modern agriculture. The objective of this work was to evaluate the selectivity of Urochloa brizantha to doses of atrazine applied in pre emergence, with two and six tillers as well as intercropping between corn + Urochloa brizantha and maize + pigeon pea in relation to its cultivation as a single crop. The work was divided into two experiments. The first phase was carried out in pots with randomized block design and 4 replicates and evaluated doses of the herbicide atrazine (0, 3, 6 and 9 L ha-1) applied in pre-emergence, with two and six tillers in the control of Urochloa brizantha. The second experiment was cultivated in the field and evaluated the intercropping between corn + Urochloa brizantha and cor + pigeon pea in relation to its single cultivation in a randomized block design and 4 replicates. Both experiments were conducted at the experimental farm of the Universidade Tecnológica Federal do Paraná - Câmpus Dois Vizinhos. The use of the herbicide Atrazine in the suppression of Urochloa Brizantha is effective, depending on the dose used and the phenological stage at the time of application. Corn intercropped with Urochloa Brizantha affected the number of grains per row and a thousand grain mass, consequently reducing corn productivity in relation to it cultivation alone. Further studies should be done in order to understand the possible beneficial effects that cover plants may bring the system and offset the yield reduction.