EUCALYPTUS SAWDUST BIOCHAR AS A CONDITIONER OF SUBSTRATES FOR PRODUCTION OF LETTUCE SEEDLINGS

Abstract

The success of lettuce (Lactuca sativa L.) production starts with obtaining good quality seedlings and the use of substrates that provide favorable chemical and physical conditions for plant development. The reuse of residues in substrate production can be an interesting approach for seedling production. The objective of this work was to evaluate the influence of biochar produced from eucalyptus sawdust on the development of lettuce seedlings. The experiment was conducted in a greenhouse using a completely randomized design with seven treatments and three replications. Great Lakes cultivar and seven substrates were used, one commercial, Bioplant® (BPL) and six substrates formed from the commercial substrate, Bioplant® + biochar (BC 5, BC 10, BC 15, BC 25, BC50 and BC 75% w/w). The following variables of emergence percentage (E) were evaluated: emergency speed index (IVE); shoot length (CPA) and root system (CSR); shoot fresh mass (MFPA) and root system (MFSR); and shoot dry mass (MSPA) and root system (MSSR), 25 days after sowing (DAS). The addition of biochar to the commercial substrate, Bioplant®, at a concentration of 5% mass, showed feasibility to be used as a substrate conditioner used in the development of lettuce seedlings of the Great Lakes cultivar.