Use of tobacco residue as substrate composition for the seedlings production of curly lettuce (Lactuca sativa L.)

Abstract

The substrate is essential in the initial development of vegetable seedlings. To analyze proportions of alternative substrate produced from tobacco residue in the production of lettuce (Lactuca sativa L.) curly lettuce seedlings, the present study was conducted in a DIC experimental design with 5 proportions of substrate and 5 replications. The substrates were the volume-by-volume mixture of alternative substrate (SA), uncharacterized tobacco residue and commercial substrate (SC) in the proportions: 100 SC; 100 AS; 25SA/75SC; 50SA/50SC and 75SA/25SC. The seedlings were evaluated at 28 days after sowing, determining: root length (CR) in cm; fresh shoot mass (MFPA); fresh root mass (MFRA); shoot dry mass (MSPA) and root dry mass (MSRA) in g, total dry mass (TDM) and shoot dry mass and root dry mass ratio (MSPA/MSR). The results indicate that there was a significant difference for the CR, MFR and MFPA, concluding that the ratio of 25SA/75SC was the most suitable for a larger root system, but when it comes to MFR or MFPA, the replacement of the commercial substrate by the alternative substrate can be total (100%).