Name: Andressa Ferreira Alves
Type: MSc dissertation
Publication date: 14/02/2023
Advisor:

Name	Role
Diolina Moura Silva	Advisor *

Examining board:

Name	Role
Antelmo Ralph Falqueto	Internal Examiner *
Diolina Moura Silva	Advisor *
Gabriel Browne de Deus Ribeiro	External Alternate *
Geraldo Rogério Faustini Cuzzuol	Internal Alternate *
Jose Aires Ventura (M/D)	Internal Examiner *
Maisa Isabela Rodrigues	External Examiner *

Summary: The demand for food is increasing in the world and so are the impacts of
conventional agriculture. Agroforestry Systems can be used to prevent soil
degradation and increase soil infiltration while enhancing agricultural production.
Chlorophyll a fluorescence has the potential to be a stress indicator evaluating the
performance of plants grown in different cropping systems. Based on biophysical
(chlorophyll a fluorescence) and biochemical (gas exchange, photosynthetic
pigments) analyses, climatological data, and cultivation systems, it was possible to
compare the two mango production systems and test the hypothesis that the
cultivation of plants de Mangifera indica L. cv. Palmer in Agroforestry System
provides greater resilience to climatic abiotic stresses such as temperature increase
and prolonged dry periods. Five-year-old mango plants in the municipality of Aracruz
- ES were used to carry out this experiment. Data collection was carried out monthly
from August 2020 to January 2021. Analyzes of transient fluorescence of chlorophyll
a, quantification of gas exchanges, chlorophyll indices and leaf pigments
(chlorophylls a and b, and carotenoid pigments) were carried out. The experimental
design was completely randomized (1x2), with mango plants submitted to 2 different
cultivation systems (Agroforestry System x Conventional System) with 10
repetitions. Data were subjected to analysis of variance (ANOVA) and also applied
to principal component analysis (PCA). The PCA showed that treatments differ
occupying different quadrants. The OJIP curves obtained from both systems
demonstrated that all plants were photosynthetically active. The formation of
negative K, L, and G Bands may indicate a greater efficiency of the SAF treatment
compared to the Conventional one. The high transpiration rate (E) and the stomatal
conductance (gs), also higher than the conventional system, show that water
availability and a reduction in temperature in the SAF microclimate may have
allowed a greater opening of the stomata. Thus, the water use efficiency (W/E) was
lower for the SAF due to the high transpiration rate, but the photosynthetic rate was
slightly higher than the Conventional one. The high and significant index of total
carotenoids in the SAF treatment may have contributed to photoprotection and
reduced photosynthetic stress. It is possible that this water advantage has
contributed to the increase in the index of photoprotective carotenoids that
contributed to the reduction of photosynthetic stress in relation to the conventional

system. The SAF System presented ecophysiological characteristics that indicate a
greater photosynthetic efficiency than the Conventional System, more studies are
needed to verify if this efficiency impacts productivity and fruit quality.

Keywords: Agroforestry, Photosynthesis, Mangifera indica L.,