Allelopathic effect of the coffee residue in emergency and Urochloa brizantha growth

Abstract

Weed management is important for the increase of agricultural crops, since they have a negative influence on yield and harvest quality. To optimize the management it is possible to use the coffee infusion residues, which has caffeine contents, a substance that has an allelopathic effect to some plants. Thus, the goal was to evaluate the allelopathic effect of coffee residues in the emergence and growth of Urochloa brizantha under product doses, gathering and application seasons in pre- and post-emergence. The experiment was carried out at UFLA, in a greenhouse with potting, with Urochloa brizantha seeds, cultivar Piata, in DBC with three replicates in the factorial (3 × 4 × 2): time of gathering (A, B, C); concentration of ground (0, 20, 50 and 100 (% W/V)) and pre- and post-emergence application. The height, fresh and dry weight, Emergence Speed Index—ESI and phytotoxicity were evaluated. It was verified the significance for pre-emergence treatments, reducing plant height, increasing phytotoxicity and reducing fresh weight. For the ESI, it was identified that only for gathering season obtained a significant result. In the phytotoxicity evaluations, it obtained interaction for the season of application with residue gathering season. For product doses and applications in pre- and post-emergence interaction was observed for phytotoxicity. It is concluded that the residue has allelopathic effect reducing growth and increasing phytotoxicity up to a maximum dose of 55.83 and 86.76 for pre- and post-emergence applications of Urochloa brizantha.