Banca de DEFESA: JERNIMO JUVENCIO CHIVALE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: JERNIMO JUVENCIO CHIVALE
DATA: 16/08/2024
HORA: 10:00
LOCAL: DCS-02
TÍTULO:

Assessing and mapping the elemental composition of coffee leaves and fruits using portable X-ray fluorescence spectrometry

PALAVRAS-CHAVES:

proximal sensor, smart agriculture, IoT agriculture

PÁGINAS: 1
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Ciência do Solo
ESPECIALIDADE: Fertilidade do Solo e Adubação
RESUMO:

Foliar analysis is crucial to monitor the nutritional status of plants ensuring high productivity and quality of products. Traditionally, the foliar analysis has been performed via wet-digestion methods. These methods are time-consuming and require a great amount of chemical reagents. Currently, it is well-known the high performance of portable X-ray fluorescence spectrometry (pXRF) to assess various earth-materials. The characterization of plant leaves and fruits is really promising via pXRF. The main advantage is the possibility to make measurements in situ contributing to real-time monitoring. In this work, it was hypothesized that pXRF measurements on intact and fresh coffee leaves may offer a reasonable assessment of nutritional status of plants when compared to laboratory conventional methods. For that, two experiments were carried out. For the first one, a coffee area (67 ha) located in the Southern of Minas Gerais State was selected and 35 georeferenced points were randomly established. In each point, eight diagnostic plant leaves were collected and directly analyzed on adaxial surface using a pXRF Bruker S1 Titan model operating at Geoxploration mode (dwell time of 60 s). After pXRF measurements, the samples from each point were oven-dried and ground and analyzed again by the following methods: i) using a pXRF Bruker S1 Titan model operating at Geoxploration mode (dwell time of 60 s); ii) using a pXRF Bruker Tracer 5g model with manufactured calibration for plant materials; iii) via ICP-OES after acid digestion. Additionally, at the same 35 points green and mature fruits were collected, oven-dried and analyzed via pXRF Bruker S1 Titan and via ICP-OES after acid digestion. The second experiment was carried out in São Sebastião do Paraíso, Minas Gerais State. Three contrasting coffee areas were selected. In each, five random points were established. Each point represented five plants. In each plant, eight diagnostic leaves were collected from August 2024 to XX, totalizing 40 leaves per point. The composite samples (n = 5) were oven-dried, ground and analyzed via pXRF Bruker Tracer 5g and conventional acid digestion method. Herein, the goal was to verify the sensibility of pXRF to monitor changes in the nutritional conditions over the time. From the first experiment, for all nutrients the pXRF measurements performed on oven-dried and ground using both Titan and Tracer models were very similar to ICP-OES acid digestion method. For K, the pXRF measurements in situ were quite like all other methodological conditions. P and Ca concentrations obtained in situ were underestimated. Regarding the micronutrients, except for Fe, all methodological conditions were comparable. From the second experiment, based on principal component plots (PCA), pXRF data was sensible to differentiate coffee areas and changes in the nutritional condition over the time. 

MEMBROS DA BANCA:
Interno - SERGIO HENRIQUE GODINHO SILVA (Membro)
Externo à Instituição - ROGÉRIO BORGUETE A. RAFAEL - UEM (Membro)
Interno - GUILHERME LOPES (Suplente)
Externo à Instituição - ENIO TARSO DE SOUZA COSTA - UFU (Suplente)
Presidente - BRUNO TEIXEIRA RIBEIRO (Membro)