Different compositions and volume of substrate in the production and quality of lettuce seedlings

Abstract

The present job work aimed to evaluate the quality of seedlings using different compositions and volumes of substrate. Randomized block design was used to conduct the experiment, in a factorial experiment 4x4, combining different volume of substrate (50cm³, 150 cm³, 250 cm³ and 350 cm³) and concentrations of organic compound (30%, 45%, 60%, 75%). There was an interaction between the factors in the variables root dry mass, total dry weight and Dickson quality index, and thereby, the gains of quality were 0,0006 (MSR) g/plant, 0,0005 (MST) g/plant and 0,0002 (IQD) for each percentage of organic compound and cm3 of added substrate volume. By contrast, variables number of leaves, plant weight and stem diameter, there was an isolated effect, with quadratic response related to the increase of volume of substrate, being its maximum points at: 480 cm³ with 6,14 leaves, 550 cm³ with 11,29 cm and 330 cm³ with 4,20 mm of diameter, respectively. The percentage elevation of organic compound and volume of substrate provides gains of quality and productivity. Moreover, the volume of substrate of 550 cm³, 480 cm³, and 330 cm³ are of larger plants height, number of leaves and stem diameter, respectively, in lettuce production.