The induction of epicormic shoots is very important for the success of vegetative propagation in forestry species, due to the high rooting capacity of the reinvigorated material. However, it is necessary to determine the most appropriate technique for this purpose, aiming for greater productivity and better reinvigoration, which may be different for each species. The objective of this search was to evaluate different induction techniques for the production of epicormic shoots in I. paraguariensis mother trees in the municipality of Urupema, Santa Catarina state, considering four rescue techniques: complete girdling (100%); semi-girdling (50%); detached live branches, and; shoots of the treetop (canopy). Three evaluations were made for: trees with epicormic shoots (%), average number of shoots and their average length (cm). Shoots were collected at 180 days after (February 2017) the application of the experiment (August 2016), separating in: rejuvenated shoots and of the treetop. At 90 days, cuttings variables were evaluated: rooting (%), calogenesis (%), average root number and their average length (cm). The semi-girdling was superior to shoot length (5.3 cm). The detached live branches obtained the highest average number of shoots (4.7), however, they were not able for cutting, due to their short length (0,6 cm). For cutting, there was only difference for the number of roots formed, and the rejuvenated material was superior (2,3) than treetop (0.8). It is recommended the use of semi-girdling technique for greater production of juvenile shoots and use reinvigorated cuttings for vegetative propagation, considering the greater number of roots formed.

Southern Brazil encompasses areas with a subtropical climate, with significant number of frosts, which challenge or even impair growing tropical eucalypts. Eucalyptus benthamii and E. smithii rise as alternative species of subtropical origin with considerable frost-tolerance. Here we accessed the genetic variation for diameter at breast height (DBH), height (H), volume (VOL), bifurcation and straightness of four provenances of E. smithii and two of E. benthamii, cultivated in randomized block design in a farm in Rio Negrinho, Santa Catarina, southern Brazil. We found considerable genetic variability for the traits, all directly associated with the selection for wood production and quality. In general, most of the genetic variability was found within the provenances (Q _d ranged from 63.6 to 73.1%), except for straightness (Q _d = 13.5% and Q _st = 81.9%). Although predicting genetic gains with provenance trials might have some drawbacks, the application of the REML/BLUP method was able to predict genetic gains for the growth variables DBH, H and VOL for provenances of the two species. The highest genetic gains were predicted for a provenance of E. smithii originated from Australia (13% for DBH, 5% for H and 6.1% for VOL). However, the genetic gains from a E. benthamii provenance from Santa Catarina state were not negligible (1.2% for DBH, 1.8 for H and 2.2% for VOL). Our results provide insights for further progeny trials aimed at investigating additive genetic variance and their components, which could improve the genetic control of the traits and assist breeding programs of E. smithii and E. benthamii.

The success of Ilex paraguariensis cutting can be affected by the population of origin, as well as the genotype and the rooting environment. Therefore, the objective of this search was to test the vegetative propagation of I. paraguariensis cuttings from two populations and their genotypes inserted in two rooting environments. The populations tested were from Três Barras (TB) and Urupema (UR), both from Santa Catarina state, by selecting seven genotypes in each. After collecting and cutting, the populations and genotypes were evenly distributed in two rooting environments, one being a mini tunnel (MT) with irrigation by micro sprinklers and the other in a greenhouse with intermittent nebulization (GWIN) with temperature and humidity control. Survival was considerably low for both populations but with singular results, as TB was better adapted to GWIN (36.5%) and UR to MT (22.6%). The rooting of cuttings varied greatly in all perspectives. The TB population obtained the best rooting results inside GWIN (21.7%), while UR did not achieve 5% of rooting in MT (2.4%) nor in GWIN (3.2%). The genotypes TB6, TB3 and TB1 obtained the best rooting results for TB in GWIN (all above 30.0%), while only UR3 obtained significant results in GWIN (18.8%). These results, mainly regarding survival and rooting, confirm that there is a strong relation involving the origin place of the material, the individuals of a population and the rooting environments.

We analyzed the rooting of sequoia mini-cuttings from different clones in the four seasons of the year and the use of the logistic model to estimate the time of maximization of rooting in each factor of analysis. Mini-cuttings of five clones grown in clonal mini-garden were placed to root in mini-tunnel in four seasons of the year. Weekly evaluations were performed (from 30 to 93 days) of these variables: survival (%), rooted mini-cuttings (%) and a number of emitted roots. These data were used to adjust the original logistic function. The experiment was set in completely randomized design, in a factorial scheme of 5 (clones) x 4 (seasons), using five replicates of 50 mini-cuttings per experimental unit. During the winter the lowest rooting of mini-cuttings was achieved (85%), with rates higher than 90% in other seasons. In winter, slower rooting also occurred, around 60-70 days, while in other seasons it was between 50-60 days after mini-cutting planting. The rooting process is dependent on the clones. Our data showed that four clones presented rooting greater than 90% and one less than 70%. In general, mini-cuttings can be performed at any time of the year, recommending the period of 90 days in mini-tunnel.

The vegetative growth of plants depends on the nutritional conditions of the soil, mainly in relation to the N element. This element favours the formation of cytokines and auxins, essential hormones for sprouting and rooting, respectively. The objective of this study was to evaluate the influence of nitrogen fertilization of Ilex paraguariensis mother trees on epicormic sprouts emission and rooting of its cuttings. Five treatments of fertilization were applied on the mother trees: control; 250 g of urea (N); 250 g of NPK (5-20-10); 500 g of NPK, and; 250 g of NPK with 30 g of micronutrients. Two evaluations (at 240 and 480 days) were carried out for: trees with sprouts emission (%), average sprouts number and their average length (cm). Sprouts were collected at both vegetative evaluations after the application of the experiment (August 2016) and sectioned into cuttings. Cuttings variables were evaluated: survival (%); rooting (%), callus formation (%) and average root number. The best response to epicormic sprouts emission was obtained with 250 g of NPK at 480 days for trees with sprouts (>75%), sprouts number (4.4) and sprouts length (9.9), but considerable results were also obtained at 240 days with urea. For cuttings, the best results were also obtained from sprouts obtained at 480 days for most treatments (>80% survival and rooting). Nitrogen fertilization is essential for a successful vegetative rescue and propagation by cuttings of I. paraguariensis, and longer periods may be able to boost these results.