Luis Gustavo Marcassa
University of São Paulo, Brazil
Title: Detection of diseases in citrus plants using fluorescence spectroscopy
Biography
Biography: Luis Gustavo Marcassa
Abstract
In recent years, there has been an increasing interest of early detection of citrus diseases to prevent great economic losses due contamination of new plants. There are two major citrus diseases: Citrus canker (Xanthomonas axonopodis pv. citri) and Huanglongbing (HLB, Candidatus Liberibacter asiaticus). Both are a serious threat to citrus production worldwide including regions in Brazil and USA. The whole process to confirm the diseases is time consuming and expensive. So, there is a demand for a fast, sensible, and selective method for the rapid detection of citrus diseases. One of these techniques, fluorescence spectroscopy has been investigated as a tool in plant studies, because it has the potential to discriminate different diseases in citrus crops and besides it is nondestructive and nonintrusive to the plant physiology. In the last decade, our group has applied laser induced fluorescence spectroscopy and fluorescence imaging spectroscopy to discriminate diseased samples with similar visual symptoms. Different computational methods were successfully used for the different citrus disease classification. In this work, we will present a review in our work on detection and classification of infected trees with citrus canker, citrus scab, HLB and zinc deficiency. Our recent results show that we obtain a high accuracy when compared either samples with citrus canker and citrus scab (100%), or samples with HLB and zinc deficiency (95%). Furthermore, the sensitivity and specificity obtained for each group is also high. Therefore, we believe that such technique can be applied in the field to detect diseases that have similar symptoms.