Produ？？o de mudas de alface em fun？？o de diferentes combina？？es de substratos

the substratum used in seedling production has a key role in the initial development of the plant. to this effect, the present work aimed to evaluate the production of lettuce seedlings for different combinations of substrata. the experiment was set up following a completely randomized design with four replications. the 20 treatments were arranged in a 4x5 factorial, the first factor consisting of four substrata (planthort i, planthort ii, planthort iii and the commercial substratum plantmax？) and the second consisting of five levels of burnt rice husks (0, 25, 50 , 75, 100%). the lettuce cultivar used was elba (lactuca sativa l.). the seeds were sown in the different substrates contained in polystyrene trays of 128 cells, at a depth of 0.5cm. the increase in the percentage of rice husks in the substrata tested, showed a similar behavior for all traits. the substrata planthort i, planthort i and planthort iii, considered as alternatives, provided greater growth relative to the substrate plantmax？, irrespective of the proportion of burnt rice husks added.