Name: Gildevan Viana Cardoso
Type: PhD thesis
Publication date: 09/03/2022
Advisor:
Name |
Role |
|---|---|
| Jose Aires Ventura (M/D) | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Antelmo Ralph Falqueto | Internal Examiner * |
| David dos Santos Martins | External Alternate * |
| Elias Terra Werner | Internal Alternate * |
| Helcio Costa | External Examiner * |
| Jose Aires Ventura (M/D) | Advisor * |
| Luiz Carlos Santos Caetano | Co advisor * |
| Paulo Cezar Cavatte | Internal Examiner * |
| Sérgio Luiz Rodrigues Donato | External Examiner * |
Summary: Banana has great socioeconomic importance for Brazil and Espírito Santo, but it is
susceptible to biotic and abiotic stresses. This study evaluated the agronomic
performance and response to water deficit of two accessions, `Ambrosia` (AAAA,
Gros Michel subgroup) and `Red Yade` (AAB, Plantain subgroup). These were
compared to the traditional varieties` Grand Naine` (AAA, Cavendish subgroup) and
`Terrinha` (AAB, Plantain subgroup) under conditions of water deficit followed by
rehydration, as well as for resistance to yellow Sigatoka, Fusarium wilt, and root
borer. The height and diameter of the pseudostem, the number of active leaves, the
mass of bunches, the mass and number of fruits, the length and diameter of the
fruits of the third bunch, the width and length of the third leaf, and the number of
days of flowering at harvest were used to evaluate agronomic performance.
Photosynthetic performance was evaluated by determining gas exchange and
chlorophyll a`s fluorescence. `Ambrosia` and Red Yade were compared,
respectively, to Grand Naine with a maximum temperature set at 28°C and Terrinha
with maximum temperatures set at 28°C and 35°C. The incidence and severity of
yellow Sigatoka were determined on the first necrotic leaf, and resistance to
Fusarium wilt was determined based on external and internal symptoms, with
subsequent calculation of disease indices. The infestation coefficient of flowering or
bunched plants was determined to evaluate resistance to the root borer. Ambrosia
had a higher bunch weight under irrigation, outperformed Grande Naine in nonirrigated management, and was resistant to yellow Sigatoka, an isolate of F.
oxysporum f.sp. cubense (Foc) and the root borer. `Red Yade` had no increase in
bunch weight and was susceptible to yellow Sigatoka, two isolates of Foc and root
borer. The water deficit initially limited the transpiration flux and CO2 diffusion,
promoting an increase in leaf temperature and a decrease in the net photosynthesis
rate without decreasing the quantum yield of PSII. Subsequently, the increase in its
duration was associated with the control of the maximum temperature at 35ºC,
leading to non-photochemical dissipation with loss of PSII performance. `Ambrosia`
showed a smaller decrease in PSII performance than `Grand Naine` and recovered
faster after rehydration. `Terrinha` presented higher leaf temperature and lower
transpiration flow than `Red Yade` when not exposed to water deficit, indicating a
greater tolerance to water deficit. In addition to the stoppage of leaf emission and
expansion at the beginning of the exposure, the prolongation of the water deficit
promoted the reduction of the total leaf area and chlorosis followed by necrosis of
the leaves from the base to the apex of the plants. It is concluded that `Red Yade`
can be recommended by adopting root borer management. `Ambrósia` shows the
potential to meet the market demand for Cavendish-type fruit, enabling the reduction
of production costs.
