Coffee straw used as mulch for germination and strength of crops and spontaneous species seedlings

The objective of this study was to evaluate the allelopathic effect of using conilon and arabica coffee straw as mulch on the emergence and development of three crops (Lactuca sativa, Cucumis sativu, Solanum lycopersicum) and three natural plants (Eupatorium maximilianii, Amaranthus hybridus and Bidens pilosa). The experiment was carried out in a greenhouse in a completely randomized design, with six repetitions. The treatments were arranged in a 3×6 factorial scheme, with three treatments of soil cover: Control (uncovered), conilon coffee straw and arabica coffee straw and six plant species.  Conilon coffee straw harmed the emergence of C. sativus, L. sativa and E. maximilianii; it reduced the emergence speed of the studied species, except for S. lycopersicum and A. hybridus; it reduced both fresh and dried C. sativus masses. Arabica coffee straw only compromised the emergence of E. maximilianii; it reduced the emergence speed of L. sativa, E. maximilianii, and A. hybridus; and it increased both fresh and dry masses of C. sativus seedlings. It is possible to conclude that conilon coffee straw can be used as mulch in S. lycopersicum crops, in the management of the weed E. maximilianii, and also to delay the emergence of B. pilosa. Arabica coffee can be used in C. sativus, S. lycopersicum and L. sativa crops in the control of E. maximilianii and to slow down the emergence of A. hybridus. Key words: Cucumis sativus, Lactuca sativa, Solanum lycopersicum L., Eupatorium maximilianii Schrad, Amaranthus hybridus L, Bidens pilosa L.