MUDAS DE ALFACE LISA COM DIFERENTES PERÍODOS DE BERÇÁRIO E SUBSTRATOS EM AMBIENTE HIDROPÔNICO.

Abstract

Seedlings production, for lettuce cultivation, is an important activity worldwide. Technical recommendations for seedling production follow a pattern: styrofoam trays and time in a nursery between 20 to 25 days. However, few trials seek improvements for this management, maintained for decades, in Brazil for lettuce seedlings. Seedlings with longer nursery periods can express better vegetative development, reflecting better adaptations after transplanting. The objective was to evaluate the influence of different nursery times on the development of lettuce seedlings, under two growth media: conventional styrofoam or phenolic foam seedlings. The sowing was carried out in styrofoam trays, or phenolic foam, to better adapt those seedlings with more time in nursery. Seedlings were maintained with 15 days of nursery, 20 days, 25 days and, finally, 30 days of nursery. The other factor, growth media, was divided in two: styrofoam or phenolic foam seedlings. In the nursery, a DIC following a 4 x 2 factorial arrangement was designed, with 8 treatments and 100 experimental units for each treatment combination. Development parameters and seedling quality were quantified, such as seedling height (cm), fresh weight (g) and dry weight (g) of seedlings. The type of substrate did not interfere with the height growth of the lettuce seedlings. However, the seedlings had a lower height when submitted to 15 days in a styrofoam tray (T1) compared to the other treatments, regardless of the type of substrate. The fresh mass of the seedlings was higher in T2, T3 and T4 with substrate compared to phenolic foam. But, that result was not observed in T1. The same response pattern was repeated when dry mass was quantified. Seedlings with a longer nursery period have higher growth parameters, which can guide nursery and lettuce producers in the development of better adapted seedlings for transplanting.