Zois Zartaloudis - Academia.edu (original) (raw)

Papers by Zois Zartaloudis

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Almost simultaneously with the psyllid''s establishment on pistachios leaves, many benefi... more Almost simultaneously with the psyllid''s establishment on pistachios leaves, many beneficial insects appear in the orchard. For this reason, plant protection products must be friendly to the ecological environment, particularly for the beneficial insects. In this work discusses whether different sampling methods lead to similar conclusions about psyllid densities in relation to sampling location (height) – sex ratio and reproductive maturity of female psyllids. Evaluated the effects of the nitrogen fertilizer on pistachio psyllid population and on nut damage. Also studied the effect of temperature on psyllid''s development, fecundity and demographic parameters. Laboratory and field studies, as well, were done on the seasonal forms and reproductive diapause of the pistachio psylla in Northern Greece. Finally, estimated the effectiveness of IGRs and other plant protection products against A. targionii in the field and in the laboratory.

There is a variety of approaches for plant disease management, but they all converge in early and... more There is a variety of approaches for plant disease management, but they all converge in early and precise detection of stress as a major factor, in order to make applications more effective. In this work, a remote sensing approach for timely detection of stress caused by the fungal pathogen Verticillium dahliae in olive trees is presented. A detection model that calculates a vegetation index based on satellite spectral information (Sentinel-2) was developed and was used to estimate the stress levels in olive trees in the Halkidiki region, which are directly related to Verticillium infestations. Index values are calculated only for pixels within the boundaries of the parcels of interest. ArcGIS 10.5 software and Python 3 were used to process the data and to produce the resulting model together with the libraries concerned. This model has been implemented in an e-infrastructure as a cloud service that offers the end user the ability to create an account and store searches and results....

IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019

In the field of plant disease protection many approaches exist, but all acknowledge the necessity... more In the field of plant disease protection many approaches exist, but all acknowledge the necessity of fast and accurate identification of the source in order to make the most efficient applications. In this work, a remote sensing approach for the detection of Verticillium dahliae in olive fields is presented. A model was created that calculates a spectral index based on Sentinel-2 data and uses it to assess the levels of stress in olive trees in the region of Chalkidiki, Greece. The derived map provides an overview of the situation concerning stress levels in olive fields across a large area and in a small amount of time. Additionally, because of the constant flow of data from the Sentinel satellites, a time series of calculations can be used as an anomaly indicator for regions of interest. This model can be implemented in an e-Infrastructure as a cloud service to further enhance its usability by relevant parties, such as agricultural advisors and scientists.

A variety of plant protection approaches exists to aid against pests and diseases, and they all c... more A variety of plant protection approaches exists to aid against pests and diseases, and they all converge in recognizing early and precisely plant stress to make applications more effective and as low-cost as possible. Consecutive advances on the field of remote sensing regarding sensor quality, data availability, procurement costs and development of smart agricultural services have enhanced the ability to assess and monitor crop health, both in individual plants and field levels. In this work, a methodology to create a detection model for olive tree stress status based on Sentinel-2 data is presented. Vegetation indices were created based on the acquired data and are presented as intermediate results of analysis in order to enhance the assessment of health status. These extracted data will be used to train and validate a machine learning classification model. The resulting model will be able to support agriculture professionals by enhancing their decisions and investigations.

ABSTRACT Η βερτισιλλίωση είναι το σημαντικότερο μυκητολογικό πρόβλημα της ελιάς. Ευθύνεται για τη... more ABSTRACT Η βερτισιλλίωση είναι το σημαντικότερο μυκητολογικό πρόβλημα της ελιάς. Ευθύνεται για την καταστροφή του φυτικού κεφαλαίου και συντελεί στην υποβάθμιση των εδαφών για πολλά χρόνια. Επειδή είναι απαραίτητο να εφαρμόζονται καλλιεργητικά και διαχειριστικά μέτρα στα δέντρα στα πρώιμα στάδια προσβολής, ώστε να επιβραδύνεται η εξάπλωση του μύκητα στον ελαιώνα, απαιτείται σήμερα η ανάπτυξη μιας νέας κλίμακας βαθμονόμησης του επιπέδου της προσβολής από το βερτισίλιο. Η κλίμακα στηρίζεται σε οπτική παρατήρηση και αξιολόγηση των δέντρων, όπου τα έντεκα επίπεδα της προσβολής καθορίζονται από το 0 έως το 10 και αντιστοιχούν από υγιές (0) μέχρι την πλήρη ξήρανση του δέντρου (10) Πιν. 1. Η παρούσα εργασία, η οποία πραγματοποιήθηκε σε ελαιώνες της Χαλκιδικής που είχαν φυσικές μολύνσεις βερτισιλίου, διερεύνησε τη δυνατότητα με τη χρήση θερμικής κάμερας υψηλής ανάλυσης και με φυλλοδιαγνωστική να επιβεβαιωθούν τα επίπεδα stress (0-3) και τα εμφανή συμπτώματα της προσβολής (4-10) σύμφωνα με την κλίμακα. Τα θερμικά τηλεπισκοπικά δεδομένα επισήμαναν τα πρώιμα στάδια της προσβολής (άδηλο stress) και διαφοροποίησαν στατιστικά τα επίπεδα προσβολής 0, 1, 2 και 3, καθώς επίσης η συγκέντρωση του ασβεστίου στα φύλλα της ελιάς διαφοροποιήθηκε και συσχετίστηκε πολύ ισχυρά με όλα τα επίπεδα προσβολής με R2 = 93%.

XI International Symposium on Apricot Culture, 1999

Η εντατικοποίηση της καλλιέργειας της ελιάς σε σχεδόν όλες τις ελαιοπαραγωγικές χώρες, η οποία οφ... more Η εντατικοποίηση της καλλιέργειας της ελιάς σε σχεδόν όλες τις ελαιοπαραγωγικές χώρες, η οποία οφείλεται στην αναγνώριση από τους καταναλωτές των ευεργετικών ιδιοτήτων αυτού του καρπού, έχει οδηγήσει στην εξάπλωση της πιο σημαντικής μυκητολογικής ασθένειας της ελιάς, δηλαδή της βερτισιλλίωσης. Η βερτισιλλίωση της ελιάς είναι αδρομύκωση και προκαλεί σταδιακή δυσλειτουργία και τελικά πλήρη απόφραξη των αγγείων του δέντρου, εν μέρει ή εξ’ ολοκλήρου, διακόπτοντας την κίνηση του νερού από τις ρίζες στα φύλλα, με αποτέλεσμα την έλλειψη της τροφοδοσίας στο προσβεβλημένο τμήμα της κόμης. Παράλληλα όμως η μείωση της κίνησης του νερού στους αγωγούς του ξυλώματος εξαιτίας της προσβολής οδηγεί και σε μείωση της μεταφοράς θρεπτικών στοιχείων από την ρίζα προς τα φύλλα. Τα αποτελέσματα της παρούσης εργασίας δείχνουν ότι η συγκέντρωση του ασβεστίου στα φύλλα των δέντρων, σε σύγκριση με τα υπόλοιπα μακροστοιχεία και ιχνοστοιχεία, μειώθηκε στους προσβεβλημένους ιστούς, στα δέντρα που παρουσίασαν σημ...

There is a trend of significantly more people to be employed in the agro-food sector in Southern ... more There is a trend of significantly more people to be employed in the agro-food sector in Southern Europe lately, mainly due to the changes occurred in the E.U. economy the last years. However, there is definitely a challenge that has to be met in order to obtain competitive agricultural products, and has to do with the management of natural resources (soil, water and energy). Eleagro (developed by GeoAnalysis S.A.) is developing a tool for remote crop monitoring with the use of Unmanned Aerial Vehicles (UAVs) and satellites, aiming at using these technologies for precision agriculture management. Remote sensing is advantageous over traditional methods of plant and soil sampling, because it offers the potential for quick area mapping of soil and plant properties and allows for quantification of crop variation (e.g. nutrient deficiency or sufficiency, pest and disease attacks and infestations, water stress and faulty irrigation equipment detection and weed infestation). Remote sensing ...

Verticillium wilt of olive is a vascular pathogen and the intensive cultivation of olives lately ... more Verticillium wilt of olive is a vascular pathogen and the intensive cultivation of olives lately in almost all olive growing countries has caused significant spread of this disease. The vascular tissues of the olive trees become plugged due to the mycelium growth, and thus the water movement from the roots to the canopy is restricted. This causes calcium deprivation of the infected tissue and finally discoloration of the periphery of the leaf lamina. At advanced stages of the infection the newer leaves roll downwards or inwards and progressively become greenish-grey to brown. This study assessed hyperspectral and thermal canopy reflectance with the use of an Unmanned Aerial Vehicle (UAV) and spaceborne multi-spectral very high-resolution remote sensing provided by the WorldView-2 (WV2) satellite for the detection of Verticillium wilt. The results show that the early stages of the infection, as determined by a new eleven-point calibration scale of the disease, were better differentia...

Some diseases do not present any particular symptoms before they cause a serious damage to plants... more Some diseases do not present any particular symptoms before they cause a serious damage to plants. Thus, the symptoms appear when it is too late to act. Verticillium dahliae is an example of this type of pathogens. At the initial stages of stress by Verticillium wilt, olive trees present a light green discoloration of the canopy. This change can be represented by differences in the acquired spectral reflectance by a remote sensor. In addition, since the fungus interrupts the water movement in the conducting tissues of olive trees, it causes stomatal closure and finally reduction in the transpiration rate. This consequently causes reduced evaporative cooling of the affected tissue and, thus, increased canopy temperature can be detected. High-resolution thermal imagery from UAV can make possible the retrieval of canopy temperature from olive orchards. Verticillium wilt constitutes the most important fungal disease of olive, since it is responsible for plant losses and soil degradation...

Antioxidants

In this research, a model for the estimation of antioxidant content in cherry fruits from multisp... more In this research, a model for the estimation of antioxidant content in cherry fruits from multispectral imagery acquired from drones was developed, based on machine learning methods. For two consecutive cultivation years, the trees were sampled on different dates and then analysed for their fruits’ radical scavenging activity (DPPH) and Folin–Ciocalteu (FCR) reducing capacity. Multispectral images from unmanned aerial vehicles were acquired on the same dates with fruit sampling. Soil samples were collected throughout the study fields at the end of the season. Topographic, hydrographic and weather data also were included in modelling. First-year data were used for model-fitting, whereas second-year data for testing. Spatial autocorrelation tests indicated unbiased sampling and, moreover, allowed restriction of modelling input parameters to a smaller group. The optimum model employs 24 input variables resulting in a 6.74 root mean square error. Provided that soil profiles and other an...

Verticillium wilt (VW) is a major disease in all the olive producing countries and leads to exten... more Verticillium wilt (VW) is a major disease in all the olive producing countries and leads to extensive losses of production and olive trees. There is not chemical treatment available currently for this pathogen and only preventive cultivation measures can be applied. In Greece, the most sensitive cultivars to VW infection are Chondrolia (Chalkidiki) and Amfissa (Fthiotida, Central Greece). Previous studies showed that remote sensing can be used to assess VW infection levels using spectral indices, such as the Carotenoid Reflectance Index 2 (CRI2) and Normalized Difference Vegetation Index (NDVI), which depict the non-visible and visible stages of the infection, respectively, suggesting a timely and area wide method to map the status and spread of the pathogen in fields grown with Chondrolia cultivar in Chalkidiki. In the same area, experimental and also commercial applications of a new Plant Growth Enhancer Formulation (PGEF) comprising of natural minerals and biological control agents provided clear visual field evidence that infected trees can be brought back in full productivity. The present work assessed the effect of the application of the PGEF on the spectral properties of the trees. The results showed that the application had a significant effect on the recovery of the olive trees, as expressed by the change in the NDVI rate of the treated trees compared to the untreated in two successive years. Furthermore, the use of CRI2 and NDVI for the second most important table olive cultivar in Greece (Amfissa) was validated for the detection of the early and advanced infection symptoms, respectively.

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019

XI International Symposium on Apricot Culture, 1999

Antioxidants