Nuove tecnologie per il monitoraggio dell'oliveto

I diversi sistemi olivicoli che caratterizzano l’olivicoltura umbra presentano ruoli e finalità diversi e richiedo tecniche di monitoraggio che differiscono per modalità e scopi. Il monitoraggio in olivicoltura ha subito un grande rinnovamento con l’avvento dell’agricoltura di precisone che, attraverso l’uso di dispositivi per la georeferenziazione e di sensori di prossimità e da remoto, ha consentito di ottimizzare la raccolta dei dati in campo. In questo breve contributo verranno presentate le principali caratteristiche e potenzialità del telerilevamento in olivicoltura, con particolare riferimento all’uso dei droni in olivicoltura di precisione

The effect of regulated deficit irrigation on growth, yield, and berry quality of grapevines (cv. Sangiovese) grafted on rootstocks with different resistance to water deficit

The aim of this work was to investigate the effect of full irrigation (FI), pre-veraison water deficit (RDI 1), or post-veraison water deficit (RDI 2) on growth, yield, and berry quality in container-grown, mature vines of cv. Sangiovese grafted onto either 1103P or SO4 rootstock over two consecutive growing seasons. Deficit irrigation regimes significantly affected vine water status of both rootstocks before and after veraison. Trunk diameter (TD) increment was markedly affected when water was restricted early, but not in the post-veraison period. Deficit irrigation from fruit set to veraison inhibited vegetative growth (TD, canopy volume, and weight of pruned wood) more than that applied from veraison to harvest. Yield was unaffected by either irrigation or rootstock in both years. Irrigation had a marked effect on berry and juice quality: the RDI 1 treatment induced the highest berry anthocyanin concentration, and the lowest titratable acidity (TA), which, instead, increased in the RDI 2 treatment. RDI treatments did not modify berry dry weight, soluble solid content, TA, anthocyanins, and epicarp total phenols in vines on both rootstocks

Postharvest UV-B exposure drives changes in primary metabolism, phenolic concentration, and volatilome profile in berries of different grape (Vitis vinifera L.) varieties

BACKGROUND The ultraviolet-B (UV-B) radiation can alter grape metabolism during berry development, but little is known on the effect of postharvest UV-B exposure. In this study, we evaluated the effect of postharvest UV-B exposure on berry primary and secondary metabolites in four grapevine varieties (Aleatico, Moscato bianco, Sangiovese, and Vermentino) in order to evaluate the possibility to increase the grape quality and its nutraceutical properties. RESULTS The treatment did not significantly affect the berry primary metabolism in terms of organic acids, carbohydrates, and amino acids profile, regardless of the variety. UV-B exposure reduced the total anthocyanin content, particularly the tri-substituted and di-substituted forms in Aleatico and Sangiovese, respectively. An overall negative effect of UV-B irradiation on the flavonols profile of Aleatico, Moscato bianco, and Vermentino berries was found, whereas it enhanced the quercetin, myricetin and kaempferol concentration in Sangiovese. The free fraction of berry volatile organic compounds increased in UV-B-treated Aleatico and Moscato bianco berries, especially C-13-norisoprenoids and volatile phenols, as well as key monoterpenes, such as the linalool derivatives. However, higher concentrations of glycosylated monoterpenes and C-13-norisoprenoids were measured in Sangiovese and Vermentino berries treated with UV-B. CONCLUSION This study provides new insights on the effect of postharvest UV-B radiation on berry secondary metabolism, highlighting a different modulation between varieties and suggesting the potential use of this technique to increase some nutraceutical and quality characteristics of grape berry

High-resolution imagery acquired from an unmanned platform to estimate biophysical and geometrical parameters of olive trees under different irrigation regimes

The experiments were conducted in a fully-productive olive orchard (cv. Frantoio) at the experimental farm of University of Pisa at Venturina (Italy) in 2015 to assess the ability of an unmanned aerial vehicle (UAV) equipped with RGB-NIR cameras to estimate leaf area index (LAI), tree height, canopy diameter and canopy volume of olive trees that were either irrigated or rainfed. Irrigated trees received water 4–5 days a week (1348 m3 ha-1), whereas the rainfed ones received a single irrigation of 19 m3 ha-1 to relieve the extreme stress. The flight altitude was 70 m above ground level (AGL), except for one flight (50 m AGL). The Normalized Difference Vegetation Index (NDVI) was calculated by means of the map algebra technique. Canopy volume, canopy height and diameter were obtained from the digital surface model (DSM) obtained through automatic aerial triangulation, bundle block adjustment and camera calibration methods. The NDVI estimated on the day of the year (DOY) 130 was linearly correlated with both LAI and leaf chlorophyll measured on the same date (R2 = 0.78 and 0.80, respectively). The correlation between the on ground measured canopy volumes and the ones by the UAV-RGB camera techniques yielded an R2 of 0.71–0.86. The monthly canopy volume increment estimated from UAV surveys between (DOY) 130 and 244 was highly correlated with the daily water stress integral of rainfed trees (R2 = 0.99). The effect of water stress on the seasonal pattern of canopy growth was detected by these techniques in correspondence of the maximum level of stress experienced by the rainfed trees. The highest level of accuracy (RMSE = 0.16 m) in canopy height estimation was obtained when the flight altitude was 50 m AGL, yielding an R2 value of 0.87 and an almost 1:1 ratio of measured versus estimated canopy height

Stima dei parametri biofisici e geometrici di olivo e vite mediante telerilevamento con SAPR

L’utilizzo dei SAPR (Sistemi Aeromobili a Pilotaggio Remoto, o droni) per le attività di telerilevamento in agricoltura è stato valutato su due colture strategiche per il comparto agricolo a livello nazionale e, in particolar modo, per la Toscana. L’elevata risoluzione spaziale e temporale che caratterizza il telerilevamento con drone consente di monitorare costantemente importanti parametri biofisici e geometrici delle colture in esame. L’obiettivo della presente tesi è stato quello di valutare la correlazione di questi parametri con misure e indici vegetazionali acquisiti da drone. Le immagini ottenute dalle fotocamere trasportate dal SAPR (multispettrale e RGB) sono state utilizzate per l’estrazione degli indici vegetazionali e per la ricostruzione 3D delle chiome di olivo e vite. In particolare, le immagini multispettrali sono state elaborate ai fini di ottenere valori di NDVI (Normalized Difference Vegetation Index) relativi alla singola pianta (oliveto) e a porzioni di filari (vigneto), mentre le immagini RGB sono state utilizzate per la ricostruzione del volume della chioma delle piante tramite un processo SfM (Structure from Motion). I valori di NDVI sono stati correlati ad alcuni parametri vegetazionali misurati in campo mentre i volumi stimati da drone sono stati confrontati con i volumi delle chiome calcolati a partire da misurazioni a terra. L’andamento dei valori di NDVI è stato coerente con il grado di vigoria delle piante (vite) e con il livello di stress idrico raggiunto durante il periodo estivo (olivo). La correlazione tra i valori di NDVI e quelli di SPAD misurati in primavera è stata buona in entrambe le colture (R2 = 0.51 e R2 = 0.74 per olivo e vite, rispettivamente). Il più alto livello di correlazione tra i valori di NDVI e l’indice di area fogliare (LAI) è stato osservato sulla vite (R2 = 0.88), mentre su olivo il coefficiente di determinazione ha presentato valori inferiori (R2 = 0.48). Le ricostruzioni tridimensionali delle chiome di olivo e vite ottenute a partire dalle immagini RGB acquisite dal drone hanno consentito di stimare in maniera precisa i volumi reali misurati a terra. La buona corrispondenza tra i valori misurati a terra e quelli stimati da drone (R2 = 0.78 e R2 = 0.82 per olivo e vite, rispettivamente) conferma le potenzialità della tecnica SfM accoppiata al telerilevamento da drone anche in campo agronomico

Soil water availability effects on plant growth, yield and fruit quality in grapevine and olive tree

Grapevine (Vitis vinifera L.) and olive tree (Olea europaea L.) are the most cultivated fruit tree crops in the Mediterranean Basin where it is produced more than half of the world production of wine and olive oil. However, the climate change is particularly concern for all the Mediterranean region where its effects are particularly severe. The increasing mean air temperature is accompanied by a decreasing tendency in the annual total precipitations, threatening viticulture and olive growing which are often not irrigated in many areas. Irrigation management in vineyards and orchards trough suitable strategies, represents one of the main agronomic practices to cope with climate change maintaining high quality productions in their traditional vocated areas. The main objective of this work was to evaluate the response of grapevine and olive tree to different irrigation regimes, in terms of plant physiology, vegetative growth, yield components and fruit quality. A specific objective for grapevine was to evaluate the effect of water deficit, in terms of timing and level of stress imposed on important secondary metabolites such as volatile organic compounds (VOCs), whereas on olive tree a possible use of remote sensing techniques for supporting precision irrigation management in the olive orchard was tested. In grapevine, water deficit applied before veraison affected vines physiology (leaf gas exchange and fluorescence) and reduced vines vegetative growth (trunk diameter, total leaf area, canopy volume), berry fresh weight and fruit yield. Post-veraison water deficit did not affect fruit yield at harvest and increase the sugars accumulation rate. Berry total anthocyanins and total flavonols concentration were enhanced when the water stress was applied before veraison. Similarly, the water deficit applied between fruit-set and veraison increased berries VOCs concentration at harvest, and it showed a positive correlation with the water stress intensity. Moreover, just few days of water deficit applied during lag-phase induced significantly higher VOCs in berries than full irrigation. Similar results were obtained for monoterpenes and other classes of aroma compounds. The seasonal patterns of berry endogenous hormones concentration may suggest a key role of the jasmonic acid derived compounds as regulators or activator of the berry VOCs accumulation. In olive, deficit irrigation allowed to save more than 50% of water compared to full irrigation with limited or no effect on fruit and oil yield. Deficit irrigation was also beneficial for oil quality, inducing higher antioxidant power compared to oils from fully irrigated trees. A significant relationship between the remoted sensed crop water stress index derived from thermal images and the stem water potential was found. The RGB images by UAV allowed to estimate tree canopy volume, highlighting differences in canopy growth pattern between irrigation regimes. Our results suggest a possible use of the RGB-thermal images from UAV to monitor both the tree water stress and its effect on canopy growth, yield and oil quality at field level, for a more efficient irrigation management in the olive orchard. We also tested the combined use of remote and proximal sensing techniques to discriminate different clusters within the orchard, with different productivity and vegetative performances. Remotely and proximally sensed indices was able to identify the soil-plant variability of the entire orchard, allowed to determine that: i) the effect of different irrigation regimes on tree performance and water productivity depended on the soil characteristics within the orchard; ii) tree vigour played a major role in determining the final fruit yield under optimal soil water availability, whereas soil features prevailed under rainfed conditions

Crescita e stato idrico costantemente monitorati grazie all’uso dei droni

Il monitoraggio degli oliveti moderni ha come obiettivo quello di fornire indicazioni volte ad aumentare la produttività e la qualità dell’olio da un lato e ridurre l’impatto ambientale dall’altro

Inflorescence Traits and Floral Quality Parameters in Promising Olive Clones (cv Leccino): Influence of the Canopy Position

In olive (Olea europaea L.), the floral quality is a key feature affecting the final fruit crop. The aim of this study was to evaluate the inflorescence traits and the floral quality parameters of three clones of Leccino cultivar (L 1.3, L 1.4, L 1.9). To assess a possible effect of light limitations on these parameters two canopy zones, internal (IZ) and external (EZ), were considered. The inflorescences were collected over two consecutive years in order to establish: (i) the characteristics of inflorescences (length, flowers per inflorescence) and flowers (open and perfect flowers); (ii) the ovary structure by histological analysis; and (iii) the viability and germination of pollen grains by in vitro culture. The preliminary results highlighted some differences among clones. The L 1.9 was the less affected by the canopy position for inflorescence morphological traits, and the presence of ovaries with at least three fully developed ovules denoting a high female fertility. Regardless of the canopy position, L 1.4 showed the highest pollen viability, suggesting its possible use as pollinator. The lower sensitivity of female and male floral organs to partial shading of L 1.9 and L 1.4 needs further investigations aimed at evaluating their suitability in high-density olive orchards

Inflorescence Traits and Floral Quality Parameters in Promising Olive Clones (cv Leccino): Influence of the Canopy Position

In olive (Olea europaea L.), the floral quality is a key feature affecting the final fruit crop. The aim of this study was to evaluate the inflorescence traits and the floral quality parameters of three clones of Leccino cultivar (L 1.3, L 1.4, L 1.9). To assess a possible effect of light limitations on these parameters two canopy zones, internal (IZ) and external (EZ), were considered. The inflorescences were collected over two consecutive years in order to establish: (i) the characteristics of inflorescences (length, flowers per inflorescence) and flowers (open and perfect flowers); (ii) the ovary structure by histological analysis; and (iii) the viability and germination of pollen grains by in vitro culture. The preliminary results highlighted some differences among clones. The L 1.9 was the less affected by the canopy position for inflorescence morphological traits, and the presence of ovaries with at least three fully developed ovules denoting a high female fertility. Regardless of the canopy position, L 1.4 showed the highest pollen viability, suggesting its possible use as pollinator. The lower sensitivity of female and male floral organs to partial shading of L 1.9 and L 1.4 needs further investigations aimed at evaluating their suitability in high-density olive orchards

Irrigazione di precisione: la sensoristica

Gli indicatori e gli strumenti utilizzati, a scopo applicativo e di ricerca, per monitorare lo stato idrico degli alberi consentono stime sempre più accurate del fabbisogno idrico