Production of Pouteria gardneriana (A. DC.) Radlk. seedlings on different substrates

The aim of this study was to evaluate growth characteristics, nutrition and seedling quality of guapeva produced on different substrates. The substrates used here included MecPlant®+rice husk (RH), fine vermiculite+subsoil+decomposed corn silage (FV+SB+DCS), and subsoil coarse sand composted cattle manure (SB+CS+CCM) at the ratios 7:3, 3:1:6, and 2:2:1, respectively, and FV+SB+RH at ratios 2:2:1 and 1:1:1; proportions are expressed on a volume basis. The following evaluations were performed 130 days after sowing: percentage of emerged seedlings; emergence speed index; stem length (SL), root collar diameter (RCD), number of leaves (NL), leaf area (LA), dry weight of the roots, stems and leaves and the whole plant; macro- and micronutrients in the leaves; ratios of SL and RCD (SL/RCD), SL and NL (SL/NL). A higher percentage of plants emerged and with greater vigor on the substrate MP+RH compared to SB+CS+CCM. The NL, LA, leaf dry weight and total plant dry weight were greater on the substrates that had DCS or CCM in their composition, but the other biometric characteristics were not affected by the different substrates. Substrates that had CCM or DCS also had the highest leaf concentrations of P, Ca, Mg, S and B. The foliar concentration of Mn was highest on the MP+RH substrate. The SL/RCD ratio was higher in the seedlings grown in substrates that included DCS and CCM in their composition, but these components yielded a lower R/S ratio. Overall, substrates with CCM and DCS favored guapeva seedling growth.   Key words: Pouteria gardneriana (A. DC.) Radlk., quality of seedlings, plant nutrition.