ROOTS OF MINI-CUTTING OF CLONES OF SEQUOIA SEMPERVIRENS IN DIFFERENT SEASONS OF THE YEAR

ABSTRACT

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.

Keywords:
Vegetative propagation; Periodicity in rooting; Rooting speed; Logistic model