Response to the foliar application of biofertilizer doses in lettuce

On lettuce fertilization, it has been common the use of alternative sources, among which the biofertilizer. The aim of this study was to evaluate the influence of different biofertilizer doses applied in solution via foliar fertilization under different concentrations over cv. 'Veronica lettuce plants. The experiment was installed in random blocks with three replicates and parcels with 64 plants. The treatments consisted in four biofertilizer doses (0%; 10%; 20% and 30%) applied via foliar fertilization at 17 days after the seedling transplanting. In each parcel, we collected three plants of the useful portion, in intervals of five days after the biofertilizer application - DAA (at 5, 10, 15, 20, 25 and 30 DAA). In each DAA we obtained the dry mass of the leaves and stem for the obtaining of the Net Assimilation Rate - TAL; Relative Growth Rate - TCR; Absolute Growth Rate - TCA; Leaf Area Ratio - RA; Leaf Mass Ratio - RMF; and Stem Ratio - RC. The biofertilizer concentrations affected the TAL, TCR and TCA on the different periods of evaluation, with maximum values reached between 10 and 15 DAA. The concentration of 20% was the one which resulted on the highest absolute growth rate and highest net assimilation rate, providing a better development and growth of lettuce plants.