| dc.description.abstract | Gladiolus (Gladiolus x grandiflorus Hort.), is a cut flower propagated by corms, very popular
for its diversity of colors and robustness. The objectives in this dissertation were: (i) describe
a production protocols for gladiolus corms from the floral stem production, (ii) verify the
answer of gladiolus to vernalization and evaluate a nonlinear vernalization response function,
(iii) characterize the effect of sprouting stages and the planting depths of gladiolus corms in
the sprouting phase, in the occurrence of harvest point date and in the perform an analysis of
the performance of the PhenoGlad model in relation these factors. The technique of producing
gladiolus corms is little known and due the scarcity of information, a corm production
protocol has been described, step by step, for this culture. Field experiments were conducted
during three years (2016, 2017 and 2018) to determine how the management of corms can
affect the production of gladiolus floral stems. Gladiolus corms were exposed a different
vernalization treatments: four temperatures (0,5°C, 5°C, 10°C and 20°C) during five storage
periods (2, 4, 6, 8 and 10 weeks). Five planting depths have been tested (5 cm, 10 cm, 15 cm,
20 cm and 25 cm) and four developmental stages during sprouting phase of gladiolus corms
(S1, S2.1, S2.2 and S2.3) were tested. Phenology data were evaluated starting at planting in
different experiments and planting dates. The PhenoGlad model was used for simulating the
harvest point date and compare with observed data in the field. To get a propagation material
with quality, care should begin at the time of harvesting the floral stem produced by the
mother corm. After a period of growth in the field, corms need to be harvested, cleaned, cured
and vernalized. This process takes about six months before a new planting can take place, in
order to have plants to be able to bloom. Knowledge of this technique is important for
reducing production costs and ensuring production sustainability and a response function can
help to bridge this gap. The response of gladiolus development to vernalization under the
conditions provided in this study was not well simulated by the proposed function. Separating
the effect of breaking dormancy and vernalization at low temperatures is a challenge and it is
therefore important to determine the cardinal temperatures vernalization in gladiolus. When
gladiolus corms are planted at greater depths a delay in the emergence speed of plants is
observed. This lower emergence rate is also observed when corms are planted with less
sprouting. The delay in emergence reflects the harvest point date of gladiolus, but does not
reduce the quality of floral stems for commercialization. From these factors, it is understood
that making change to the source code oh the PhenoGlad model was not necessary, whereas in
practice, even overestimating the model, it correctly adjusts the harvest point date of floral
stems, in advance. | |
