poster - International Conference of Agricultural Engineering

Transpiration of Eucalyptus spp seedlings submitted to different
fertigation managements
Magali R. Silva 1* , Simone F. Ciavatta 1 , Danilo Simões 1
1 Universidade Estadual Paulista - Sector of Forestry Sciences, Postbox 237, Postcode
18610-307 - Botucatu, Sao Paulo, Brazil.
*Corresponding author. E.mail: magaliribeiro@fca.unesp.br
Abstract
The transpiration of seedlings is an important parameter for evaluating physiological quality,
as well as constituting a good indicator for definition of initial performance of seedlings after
plantation in the field. Under identical conditions, transpiration differences can indicate a
stomatic mechanism of greater or lesser efficiency, implying water savings by the plant. The
tolerance of forest species seedlings to drought, is determined by several factors and can be
modified by nutritional and water management. In this sense, the present work aimed to
evaluate the influence of nutritional management, by means of fertigation, in the transpiration
of seedlings of three species: Eucalyptus grandis, E.urophylla and the hybrid E. grandis x E.
urophylla. The seedlings were produced in 50 cm 3 plastic tubes with substrate based on the
bark of pine and vermiculite. The assay was conducted by a completely randomized 3x2
factorial delineation (species and frequencies of fertigation). Fertigation during growth and
hardening phase were parceled 1, 2, 3 and 6 times per week, maintaining application of the
same total fertilizer quantity, and delivered by subirrigation. The results were submitted to
variance analysis. The variables found significant by the F test were submitted to Tukey’s
test at 5% probability. The data showed that E. grandis seedlings fertigated once or twice
weekly, in other words, with more concentrated nutritive solutions, presented lower
transpiration values. In relation to seedlings of E. urophylla and of E. grandis x E. urophylla,
fertigation parceling produced no clear effect on transpiration. The E. urophylla seedlings
fertigated twice weekly presented higher transpiration values while the other treatments were
similar to each other. Seedlings of E. grandis x E. urophylla produced the lowest transpiration
values when submitted to lesser and greater fertigation parceling, that is, both more
concentrated and diluted nutritive solutions yielded statistically similar values. Species
analysis revealed that all seedlings presented statistically similar results when fertigated
once per week. The E. grandis seedlings fertigated twice weekly demonstrated the lowest
transpiration values. Among seedlings submitted to greater parceling (3 and 4 times per
week) the lowest transpiration values were obtained with E. urophylla. Thus, it is concluded
that the species transpiration responds differentially to fertigation parceling.
Key words: fertilization, nursery, physiology, cuttings.
1. Introduction
The transpiration of seedlings is a parameter to evaluate the physiological quality and,
according to Silva (1998), it can be a good indicator to define the survival of seedlings after
field planting. According to Inoue & Ribeiro (1988), transpiration is a phenomenon strongly