THE USE OF HYDROGEL COMBINED WITH APPROPRIATE SUBSTRATE AND FERTILIZER IMPROVE QUALITY AND GROWTH PERFORMANCE OF Mimosa scabrella BENTH. SEEDLINGS

Abstract

Mimosa scabrella is a pioneer species that occurs mainly in the ombrophilous mixed forests of southern Brazil, assuming considerable economic relevance. As limited information is available concerning the most adequate substrates for producing seedlings of this species, we evaluated the combined effect of  hydrogel with three types of substrates and four fertilizers in the initial growth and quality of seedlings of M. scabrella. The substrates were prepared with distinct proportions of the organic compound Turfa Fértil (TF), vermiculite (VM) and pine bark (PB): 1 (70% of TF, 10% of VM and 20% of PB), 2 (40% of each TF and VM and 20% of PB), and 3 (70% of TF, 10% of VM and 20% of PB). The fertilizers consisted of a slow release formula (A), a traditional NPK (B), a compost of superphosphate and potassium chloride (C) and no fertilizer (D). The use of hydrogel exerted a positive effect on the growth of M. scabrella seedlings, probably by retaining more water and enabling increased nutrient absorption. In general, the polymer implicated in increased Dickson quality index (DQI). Additionally, the combination of organic compound and vermiculite in equilibrated proportions aid by pinus bark (substrate 2) were the best substrate for M. scabrella. Finally, adding the fertilizers A or B resulted in the best performance of growth. In conclusion, the combined effect of hydrogel, substrate mixture and fertilizers provided the best quality indexes of M. scabrella seedlings; however, further assessment of their dosages are encouraged for setting the optimal quantities.