Banca de DEFESA: ALESSANDRA PAZ DE LIMA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ALESSANDRA PAZ DE LIMA
DATE: 25/02/2026
TIME: 09:00
LOCAL: Embrapa Agrobiologia (Sala Multimeios)
TITLE:

Effects of Different Organic Substrates on Seedling Production and Cultivation of Passiflora spp

KEY WORDS:

Millicompost, Passiflora alata, Passiflora edulis, Pot cultivation, Seedling production

PAGES: 90
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Manejo e Conservação do Solo
SUMMARY:

The increasing demand for more sustainable agricultural production systems has stimulated the use of alternative substrates, especially those of organic origin, capable of reducing costs, adding value to residues, and promoting plant development at different phenological stages. In this context, this dissertation aimed to evaluate the potential of millicompost and commercial substrates on the early development and seedling quality of Passiflora alata and on the reproductive performance of sour passion fruit (Passiflora edulis f. edulis), integrating morphophysiological, phenological, and environmental variables.

The studies were conducted in two complementary stages. In the first stage, emergence, early growth, and seedling quality of plants originating from seeds and pre-germinated seedlings cultivated in different substrates were evaluated. In the second stage, flowering and fruiting of plants grown in pots under semi-field conditions were analyzed, using mixtures of organic substrates and an Ultisol (Argissolo), from October 2024 to August 2025.

Results from the initial stage showed that millicompost provided a higher emergence speed index, shorter mean emergence time, and greater mean emergence speed, indicating more favorable physicochemical conditions for germination and early seedling establishment. Although the final emergence percentage did not differ among substrates, emergence dynamics were clearly influenced by the type of material used. Millicompost also stood out in terms of root ball stability, number of leaves, stem diameter, plant height, and accumulation of shoot and root biomass, especially in pre-germinated seedlings. SIPA showed intermediate performance, whereas Organosolo® and the sand–vermiculite mixture showed lower values for most variables. The Dickson Quality Index confirmed the superiority of organic substrates, highlighting millicompost for seedlings and SIPA for seed-derived plants, indicating that the response to the substrate depends on the initial physiological stage of the propagule.

During the reproductive stage, significant differences were observed among treatments for the total number of flowers at anthesis, aborted flowers, and formed fruits, with emphasis on the treatment containing gongocompost combined with Ultisol. Peak flowering occurred in April 2025, coinciding with the highest number of formed fruits and aborted reproductive structures. Substrates containing millicompost and vermicompost resulted in a higher number of fruits harvested per plant, while floral abortion rate, fruit abortion rate, and fruit set did not differ among treatments. These results indicate that substrate effects are mainly expressed through stimulation of flower emission and fruit formation rather than through reductions in abortion.

Redundancy Analysis (RDA) revealed a strong relationship between environmental variables and phenological responses, with high explanatory power of the model. Maximum temperature showed a negative correlation with the number of aborted flowers and fruits, whereas maximum relative humidity was positively correlated with the number of flowers and fruits formed, indicating a favorable effect of this variable on the reproductive processes of passion fruit, without a significant influence on abortion.

Overall, the results demonstrate that millicompost has high potential as a component of agricultural substrates, promoting plant performance from emergence and seedling quality to flowering and fruiting of passion fruit. The superiority observed in organic substrates reinforces the importance of materials with adequate physical structure, water retention capacity, and nutrient availability, as well as the interaction between substrate and propagule type. Therefore, the use of millicompost represents a technically viable and environmentally sustainable alternative for seedling production and passion fruit cultivation in agricultural systems.

COMMITTEE MEMBERS:
Presidente - ***.320.637-** - MARIA ELIZABETH FERNANDES CORREIA - EMBRAPA
Interno - 1399485 - ANDRES CALDERIN GARCIA
Externo à Instituição - MARCO ANTONIO DE ALMEIDA LEAL - EMBRAPA