The aim of this study was to determine the influence of different nitrogen doses and substrate formulations on the minicutting technique of Eucalyptus dunnii Maiden. The clonal minigarden of 90-day-old seedlings was cultivated in the commercial substrate of pine bark and vermiculite (tubes of 55 cm3). The dose test used a unique source (NH4NO3) in the following concentrations of N: 0.2; 0.4 and 0.6 g L-1. Each ministump was weekly watered with 10 mL of the tested solution. Five different substrate mixtures were tested: a commercial substrate with pine bark special, medium size vermiculite, carbonized rind of rice and incorporated fertilization. The survival of ministumps in the nitrogen doses tested was 100% until the 10th collection, after which, it was observed mortality in 0.4 treatment (1 ministump). All the evaluated characteristics showed direct relation to the N doses tested. The higher values were achieved with higher doses. The substrates presented statistical differences in the survival and formation of seedlings (collar diameter and height) and vegetative vigor of seedlings. In conclusion, the minicutting technique of E. dunnii is influenced by the nitrogen fertirrigation and the substrate. It is suggested the dose of 0.6 g L-1 and the substrate formed by the commercial substrate with pine bark and vermiculite + medium size vermiculite + carbonized rind of rice (1:1:1) + incorporated fertilization.
Fertirrigation; ammonium nitrate; clonal silviculture
