Abstract

The high nutrient content in organic composted waste is an alternative source of fertilizer for use in agriculture and for re-establishment of native forests. This work had as an objective is aimed to evaluate the growth of Pterogyne nitens (wild poinsettia) seedlings, a rainforest native species, on substrates containing composts of organic garbage and tree pruning. A greenhouse experiment was conducted, in which seedlings were randomly transplanted into tubes to establish 8 treatments, 4 substrates and 2 irrigation depths, in a 4×2 factorial arrangement, with three replicates. The substrates were: S1: 80% tree pruning compost and 20% garbage compost; S2: 100% tree pruning compost; S3: 80% tree pruning compost and 20% commercial substrate; S4: 100% commercial substrate. Irrigation was applied to supply 50% (Depth 1) and 100% (Depth 2) of daily reference evapotranspiration. Plantlet growth was not affected by irrigation, but plantlets were significantly taller in the treatment with 80% tree pruning plus 20% garbage composts. It was concluded that seedling formation of wild Poinsettia in a greenhouse environment can be satisfactorily obtained by supplying half of daily reference evapotranspiration depth and a substrate consisting of 80% pruning tree plus 20% garbage composts, which is suitable to replace the commercial fertilizer product.

Key words: Growing media, organic compost, re-establishment native plants.