Substratos alternativos formulados com resíduos agroindustriais em diferentes volumes de recipientes na produção de mudas de Handroanthus heptaphyllus e Schinus terebinthifolius

Abstract

The substrate is considered one of the conditioners of standart quality of seedlings in nursery, being fundamental that, it presents ideal characteristics for use in seedlings production. Allied to the substrate, another factor that is considered in seedlings production is the container, which will direct the growth of the root system and prevent its folding. Based on this, the study aimed to evaluate different sizes of containers and the potential of alternative substrates formulated with agroindustrial residues in the production of Handroanthus heptaphyllus (Mart.) Mattos and Schinus terebinthifolius Raddi. seedlings. The experiments were conducted in a completely randomized design with four replications, in a factorial scheme (containers and substrates), consisting on two different container volumes (110 and 180 cm3 ) and ten mixtures of substrates (100CS - 100% commercial substrate; 10CRH - 90 % CS + 10% carbonized rice husk (CRH); 20CRH - 80% CS + 20% CRH; 30CRH - 70% CS + 30% CRH; 10HRH - 90% CS + 10% hydrolyzed rice husk - 80% CS + 20% HRH; 30HRH - 70% HRH + 30% HRH; 10CPK - 90% CS + 10% crushed peach kernel (CPK); 20CPK - 80% CS + 20% CPK; CS + 30% CPK). At 90 and 108 days after the emergence of S. terebinthifolius and H. heptaphyllus seedlings, respectively, the morphological parameters (height, stem diameter, shoot dry matter, root dry matter, total dry matter, Dickson quality index and leaf area) and physiological (Falker chlorophyll index a and b and the maximum photochemical efficiency of PSII (Fv/Fm)). Data were submitted to analysis of variance and the means were compared by t-test (containers) and Scott-Knott (substrates) at 5% probability of error. From our results or findings, considering most of the evaluated parameters, the 180 cm3 container provided fast growth for both species, S. terebinthifolius and H. heptaphyllus, giving seedlings with adequate size for shipment at 90 and 108 days, respectively. Even though some substrates have demonstrated restrictions on seedlings growth, formulations up to 20% of CRH or HRH or CPK are indicated for production of S. terebinthifolius seedlings. Formulations up to 30% of CRH or HRH or 10% of CPK are indicated for production of H. heptaphyllus seedlings.