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The application of new technologies (e.g. Internet of Things, mechatronics, remote sensing) to the primary sector will reduce the production costs, limit the waste of primary materials, and reduce the release of polluting compounds into the environment. Precision agriculture (PA) has been growing in the last years thanks to industry efforts and development of applications for diagnostic purposes. Many applications in PA use vegetation indices to measure phenology parameters in terms of Leaf Area Index (LAI). In this context, the correlation of some vegetation indices were analyzed with respect to the durum wheat canopy, evaluating two different phenological stages (elongation and maturity). The results show that for the first stage of growth, the Enhanced Vegetation Index (EVI) was the best-correlated vegetation index with LAI, while the Land Surface Water Index (LSWI) was more reliable for the following stage of growth. Considering trials findings, a fuzzy expert system was developed to combine EVI and LSWI, obtaining a new combined index (Case-specific Fuzzy Vegetation Index) that better represents the LAI in comparison with the single indices. Thus, this approach could give place to a better representative vegetation index of a different biological condition of the plant. It may also serve as a reliable method for wheat yield forecasting and stress monitoring.

Heavy metal excess in soil represents a critical problem for crop productivity. Among these pollutants, cadmium (Cd) is one of the most dangerous in terms of food-chain contamination. Two durum wheat near-isogenic lines (NILs) and 12 commercial varieties (cultivars Arcangelo, Aureo, Aziziah, Cappelli, Cirillo, Creso, Iride, Maestrale, Parsifal, Russello, Strongfield, and Svevo) of durum wheat were exposed to a nontoxic level of Cd to evaluate its concentration in grains, roots, and shoots, as well as effects on biomass production. Cultivar Iride showed the most interesting behavior because it stored large amounts of Cd in the roots, preventing its translocation to grains. On the contrary, Cirillo and Svevo genotypes were characterized by a high Cd concentration in the grains. Furthermore, a molecular characterization employing the ScOPC20 marker associated with the Cd uptake locus has shown the absence of the expected fragment in the Iride variety and in other varieties characterized by low Cd concentration, as well as the presence of it in high Cd-accumulating cultivars.

Fruit quality is certainly influenced by biotic and abiotic factors, and a main quality attribute is the external appearance of the fruit. Various possible agronomical approaches are able to regulate the fruit microenvironment and, consequently, improve fruit quality and market value. Among these, fruit bagging has recently become an integral part of fruits’ domestic and export markets in countries such as Japan, China, Korea Australia and the USA because it is a safe and eco-friendly technique to protect fruits from multiple stresses, preserving or improving the overall quality. Despite increasing global importance, the development of suitable bagging materials and, above all, their use in the field is quite laborious, so that serious efforts are required to enhance and standardize bagging material according to the need of the crops/fruits. This review provides information about the effects of bagging technique on the fruit aspect and texture, which are the main determinants of consumer choice.

Monitoring Xylella fastidiosa is critical for eradicating or at least containing this harmful pathogen. New low-cost and rapid methods for early detection capability are very much needed. Metabolomics may play a key role in diagnosis; in fact, mobile metabolites could avoid errors in sampling due to erratically distributed pathogens. Of the various different mobile signals, we studied dicarboxylic azelaic acid (AzA) which is a key molecule for biotic stress plant response but has not yet been associated with pathogens in olive trees. We found that infected Olea europaea L. plants of cultivars Cellina di Nardò (susceptible to X. fastidiosa) and Leccino (resistant to the pathogen) showed an increase in AzA accumulation in leaf petioles and in sprigs by approximately seven- and sixfold, respectively, compared with plants negative to X. fastidiosa or affected by other pathogens. No statistically significant variation was found between the X. fastidiosa population level and the amount of AzA in either of the plant tissues, suggesting that AzA accumulation was almost independent of the amount of pathogen in the sample. Furthermore, the association of AzA with X. fastidiosa seemed to be reliable for samples judged as potentially false-negative by quantitative polymerase chain reaction (cycle threshold [Ct] > 33), considering both the absolute value of AzA concentration and the values normalized on negative samples, which diverged significantly from control plants. The accumulation of AzA in infected plants was partially supported by the differential expression of two genes (named OeLTP1 and OeLTP2) encoding lipid transport proteins (LTPs), which shared a specific domain with the LTPs involved in AzA activity in systemic acquired resistance in other plant species. The expression level of OeLTP1 and OeLTP2 in petiole samples showed significant upregulation in samples positive to X. fastidiosa of both cultivars, with higher expression levels in positive samples of Cellina di Nardò compared with Leccino, whereas the two transcripts had a low expression level (Ct > 40) in negative samples of the susceptible cultivar. Although the results derived from the quantification of AzA cannot confirm the presence of the erratically distributed X. fastidiosa, which can be definitively assessed by traditional methods, we believe they represent a fast and cheap screening method for large-scale monitoring.

Background Among cereals, durum wheat (Triticum turgidum L. subsp. durum) accumulates cadmium (Cd) at higher concentration if grown in Cd-polluted soils. Since cadmium accumulation is a risk for human health, the international trade organizations have limited the acceptable concentration of Cd in edible crops. Therefore, durum wheat cultivars accumulating low cadmium in grains should be preferred by farmers and consumers. To identify the response of durum wheat to the presence of Cd, the transcriptomes of roots and shoots of Creso and Svevo cultivars were sequenced after a 50-day exposure to 0.5 μM Cd in hydroponic solution. Results No phytotoxic effects or biomass reduction was observed in Creso and Svevo plants at this Cd concentration. Despite this null effect, cadmium was accumulated in root tissues, in shoots and in grains suggesting a good cadmium translocation rate among tissues. The mRNA sequencing revealed a general transcriptome rearrangement after Cd treatment and more than 7000 genes were found differentially expressed in root and shoot tissues. Among these, the up-regulated genes in roots showed a clear correlation with cadmium uptake and detoxification. In particular, about three hundred genes were commonly up-regulated in Creso and Svevo roots suggesting a well defined molecular strategy characterized by the transcriptomic activation of several transcription factors mainly belonging to bHLH and WRKY families. bHLHs are probably the activators of the strong up-regulation of three NAS genes, responsible for the synthesis of the phytosiderophore nicotianamine (NA). Moreover, we found the overall up-regulation of the methionine salvage pathway that is tightly connected with NA synthesis and supply the S-adenosyl methionine necessary for NA biosynthesis. Finally, several vacuolar NA chelating heavy metal transporters were vigorously activated. Conclusions In conclusion, the exposure of durum wheat to cadmium activates in roots a complex gene network involved in cadmium translocation and detoxification from heavy metals. These findings are confident with a role of nicotianamine and methionine salvage pathway in the accumulation of cadmium in durum wheat. Electronic supplementary material The online version of this article (10.1186/s12870-018-1473-4) contains supplementary material, which is available to authorized users.

The colonization behavior of the Xylella fastidiosa strain CoDiRO, the causal agent of olive quick decline syndrome (OQDS), within the xylem of Olea europaea L. is still quite controversial. As previous literature suggests, even if xylem vessel occlusions in naturally infected olive plants were observed, cell aggregation in the formation of occlusions had a minimal role. This observation left some open questions about the whole behavior of the CoDiRO strain and its actual role in OQDS pathogenesis. In order to evaluate the extent of bacterial infection in olive trees and the role of bacterial aggregates in vessel occlusions, we tested a specific fluorescence in situ hybridization (FISH) probe (KO 210) for X. fastidiosa and quantified the level of infection and vessel occlusion in both petioles and branches of naturally infected and non-infected olive trees. All symptomatic petioles showed colonization by X. fastidiosa, especially in the larger innermost vessels. In several cases, the vessels appeared completely occluded by a biofilm containing bacterial cells and extracellular matrix and the frequent colonization of adjacent vessels suggested a horizontal movement of the bacteria. Infected symptomatic trees had 21.6 ± 10.7% of petiole vessels colonized by the pathogen, indicating an irregular distribution in olive tree xylem. Thus, our observations point out the primary role of the pathogen in olive vessel occlusions. Furthermore, our findings indicate that the KO 210 FISH probe is suitable for the specific detection of X. fastidiosa.

Due to its complex epidemiological cycle, including several polyphagous insect vectors and host plants, and the absence of efficient control strategies, Bois Noir (BN) disease of grapevine is encroaching wider territories in the main viticultural areas worldwide. Molecular approaches allowed to increase the knowledge about its etiological agent (Bois Noir phytoplasma, BNp; ‘Candidatus Phytoplasma solani’ species), revealing interesting features concerning BNp population structure and dynamics and transmission routes in vineyard agro‐ecosystems. In the present study, a multilocus sequence typing approach (vmp1 and stamp genes) was utilised for describing the genetic diversity among BNp strain populations in 17 vineyards localised in two distinct geographic areas in Tuscany (central Italy). The results confirmed that BNp ecology in Tuscan vineyards is mainly associated to the bindweed‐related host system, and allowed the identification of 14 BNp vmp1/stamp genotypes. Interestingly, the prevalent genotype (Vm43/St10) was never found in grapevines outside of Tuscany. Moreover, statistical analyses showed significant differences between the composition of BNp strain populations identified in grapevines from north‐western and central‐eastern Tuscany. These results reinforce the hypothesis that distinct geographic areas, probably associated with different ecological niches, can drive the selection of BNp strains, also favouring the entrance of unusual ‘Ca. Phytoplasma solani’ genotypes in vineyards.

Plant protection represents one of the strategies to fill the yield gap and to achieve food security, a key topic for India development. Analysis of climate risks for crops indicates that South Asia is one of the regions most exposed to the adverse impact on many plants that are relevant to inhabitants exposed to food safety risks. Furthermore, accumulation of pesticide residues in the aquatic and other ecosystems is becoming a significant threat in India. These perspectives require to develop programs of crop protection that can be feasible according to Indian rural development and pollution policy. Here we review the research works done on soil solarization in India. Soil solarization (also called plasticulture) is an eco-friendly soil disinfestations method for managing soil-borne plant pathogens. This is the process of trapping solar energy by moist soil covered with transparent polyethylene films and chemistry, biology and physical properties of soil are involved in pest control. So far, this technique is applied in more than 50 countries, mostly in hot and humid regions. India has 29 states and these states fall under five climatic zones, from humid to arid ones. We report pest management application in different climatic zones and their effects on production, weeds, nematodes, and pathogenic microorganisms. The analysis of soil temperatures and crop protection results indicate as environmental requirement for soil solarization fits in most of Indian rural areas. Soil solarization is compatible with future Indian scenarios and may support Indian national food security programs.

Wheat, the main food source for a third of world population, appears strongly under threat because of predicted increasing temperatures coupled to drought. Plant complex molecular response to drought stress relies on the gene network controlling cell reactions to abiotic stress. In the natural environment, plants are subjected to the combination of abiotic and biotic stresses. Also the response of plants to biotic stress, to cope with pathogens, involves the activation of a molecular network. Investigations on combination of abiotic and biotic stresses indicate the existence of cross-talk between the two networks and a kind of overlapping can be hypothesized. In this work we describe the isolation and characterization of a drought-related durum wheat (Triticum durum Desf.) gene, identified in a previous study, coding for a protein combining features of NBS-LRR type resistance protein with a S/TPK domain, involved in drought stress response. This is one of the few examples reported where all three domains are present in a single protein and, to our knowledge, it is the first report on a gene specifically induced by drought stress and drought-related conditions, with this particular structure.

The rapid development of new technologies and the changing landscape of the online world (e.g., Internet of Things (IoT), Internet of All, cloud-based solutions) provide a unique opportunity for developing automated and robotic systems for urban farming, agriculture, and forestry. Technological advances in machine vision, global positioning systems, laser technologies, actuators, and mechatronics have enabled the development and implementation of robotic systems and intelligent technologies for precision agriculture. Herein, we present and review robotic applications on plant pathology and management, and emerging agricultural technologies for intra-urban agriculture. Greenhouse advanced management systems and technologies have been greatly developed in the last years, integrating IoT and WSN (Wireless Sensor Network). Machine learning, machine vision, and AI (Artificial Intelligence) have been utilized and applied in agriculture for automated and robotic farming. Intelligence technologies, using machine vision/learning, have been developed not only for planting, irrigation, weeding (to some extent), pruning, and harvesting, but also for plant disease detection and identification. However, plant disease detection still represents an intriguing challenge, for both abiotic and biotic stress. Many recognition methods and technologies for identifying plant disease symptoms have been successfully developed; still, the majority of them require a controlled environment for data acquisition to avoid false positives. Machine learning methods (e.g., deep and transfer learning) present promising results for improving image processing and plant symptom identification. Nevertheless, diagnostic specificity is a challenge for microorganism control and should drive the development of mechatronics and robotic solutions for disease management.

Citrus tristeza closterovirus (CTV) has been found several times in the last decades in Italy, and plant protection services are involved in monitoring and surveillance. Although orchards linked to the citrus industry are well monitored, there is an underestimated risk of viruses or virus-like diseases in ornamental nurseries. Our aim was to modify a CTV monitoring program to include other viruses (Citrus variegation virus, CVV; Citrus psorosis virus, CPsV) and viroids (Citrus exocortis viroid, CEVd; Hop stunt viroid, HSVd; Citrus bent leaf viroid, CBLVd; Citrus dwarfing viroid, CDVd; Citrus bark cracking viroid, CBCVd). Ornamental mother plants were monitored for four years in 15 nurseries in two locations in central Italy using inexpensive multiplex RT-PCR protocols. CTV incidence was 1.6–13.5%, with an average distribution of 11.9%. The average incidence of CVV and CPsV was 6.3% and 2.7%, respectively. Higher CTV, CVV and CPsV incidences were observed in C. x paradisi, C. grandis and C. x clementina. The most widespread viroid identified was CEVd (32.9%), frequently observed in C. x limonia and C. limon. HSVd (10.5%), and CDVd (7.1%) were mostly found in C. x limonia. Lower infection rates were observed for CBLVd (2.0%) and CBCVd (1.4%). However, the nurseries’ response to the virus alert by the protection services was only partially effective. Although the CTV incidence was lower in nurseries re-checked after the initial detection, it was not eradicated from two nurseries out of three, and the occurrence of viroids was reduced in just one nursery. Given that dangerous viruses along with the concomitant spread of viroids have unfortunately become a fact of every day life, multiplex RT-PCR diagnoses are likely to play an increasing role in warning nursery managers of possible infections.

The disease outbreak of Xylella fastidiosa subsp. pauca strain CoDiRO (Complesso del Disseccamento Rapido dell’Olivo) in Salento (Apulia, South Italy) associated with severe cases of olive quick decline syndrome may represent not just a new disease paradigm, but a challenge for policy formulation and science communication in plant pathology. Plant health management can be achieved by applying a technocratic model, in which objective science is thought to directly inform policy-making, or via decisionistic or inclusive models, in which scientific considerations drive risk assessment. Each could be applied to X. fastidiosa and CoDiRO strain management, thanks to consistent literature related to pathogen/host interactions, hosts, vectors, and diagnostic tools, reviewed here. However, consensus among stakeholders seems to be necessary in order to avoid plant health management failures or gridlocks, due to environmental, economic, and social implications in the X. fastidiosa threat. Here we discuss the role of consensus in building scientific opinion, reporting different approaches of governance after severe disease outbreaks in Europe. These case studies, and the available risk analysis for Xylella strains, should drive policy formulations towards more cooperative networks.

We have developed a vision-based program to detect symptoms of Olive Quick Decline Syndrome (OQDS) on leaves of Olea europaea L. infected by Xylella fastidiosa, named X-FIDO (Xylella FastIdiosa Detector for O. europaea L.). Previous work predicted disease from leaf images with deep learning but required a vast amount of data which was obtained via crowd sourcing such as the PlantVillage project. This approach has limited applicability when samples need to be tested with traditional methods (i.e., PCR) to avoid incorrect training input or for quarantine pests which manipulation is restricted. In this paper, we demonstrate that transfer learning can be leveraged when it is not possible to collect thousands of new leaf images. Transfer learning is the re-application of an already trained deep learner to a new problem. We present a novel algorithm for fusing data at different levels of abstraction to improve performance of the system. The algorithm discovers low-level features from raw data to automatically detect veins and colors that lead to symptomatic leaves. The experiment included images of 100 healthy leaves, 99 X. fastidiosa-positive leaves and 100 X. fastidiosa-negative leaves with symptoms related to other stress factors (i.e., abiotic factors such as water stress or others diseases). The program detects OQDS with a true positive rate of 98.60 ± 1.47% in testing, showing great potential for image analysis for this disease. Results were obtained with a convolutional neural network trained with the stochastic gradient descent method, and ten trials with a 75/25 split of training and testing data. This work shows potential for massive screening of plants with reduced diagnosis time and cost.

The health status of the native grapevine Vitis vinifera subsp. sylvestris (Gmeli) Hegi in natural areas in Europe has received little attention. A survey was carried out on wild grapevines in Tuscany (Italy), where isolates of the Grapevine rupestris stem pitting virus (GRSPaV), Grapevine leafroll-associated virus 1 and 3 (GLRaV-1 and GLRaV-3) and Grapevine virus A (GVA) were detected. The complete coat protein (CP) region of these isolates was sequenced to investigate the relationship of the viral variants from Tuscan wild grapevines with isolates from different geographical origins. According to the phylogenetic analyses, GLRaV-1 and GLRaV-3 isolates from Tuscan wild grapevines clustered with isolates from cultivated grapevines with nucleotide sequence identities ranging from 66% to 87% and from 72.5% to 99% respectively, without any correlation between the distribution and geographical origin. Conversely, GRSPaV and GVA isolates clustered together with other Italian isolates from V. vinifera with nucleotide sequence identities ranging from 71.14% to 96.12% and from 73.5% to 92%, respectively. Our analysis of the whole amino acid sequences revealed a high conservation level for the studied proteins explained by a selective pressure on this genomic region, probably due to functional constraints imposed on CP, such as specific interactions with cellular receptors in the insect vectors necessary for successful transmission. In addition, analyses of genetic recombination suggest no significant point mutations that might play a significant role in genetic diversification. The dN/dS ratio also estimated a low number of non-silent mutations, highlighting the purifying selective pressure. The widespread distribution of the Rugose wood complex (GRSPaV and GVA associated disease) in comparison with the Grapevine Leafroll associated viruses (GLRaV-1 and -3) could explain the major geographical correlation found for the viral variants detected in Tuscany.

RFID sensors are effective for real-time temperature monitoring during solarization.Lesions of biodegradable film can be highlighted by RFID temperature assessment.Easy-to-use monitoring tools help the farmer to understand the thermal effect. Soil-borne pathogen and weed control can be achieved by soil solarization even if estimation of time treatment is difficult to assess. Thus, due to dependence to environmental conditions and the need to minimize the time of treatments, the implementation of monitoring tools may help in solarization managements, especially when biodegradable films were applied or weather condition are subjected to significant variation. Digitalization of data relative to plants thanks to RFID applications has been used for health or treatment monitoring, sample collecting and retrieving sanitary information: this paper presents the testing of RFID sensor application for soil solarization purposes. Different matrices were selected to assess RFID temperature sensors performances. Sandy, loam and clay soils with different moisture-holding capacity were selected for sensor burial. Sensors were covered by 5 or 10cm of fresh matrix and read immediately. Reliability was found to be more than 90% in all tested conditions, while higher failure in tag reading was recorded in clay soil at 90% of moisture-holding capacity (-7% of tag reliability). Soil solarization treatment was carried out as case of study during a period characterized by changeable weather using a biodegradable film. Data, expressed as thermal addition and temperature classes, collected continuously by sensors permitted to design real-time graphs that help the farmer to understand the thermal effect caused by treatment. Throughout the second and third week of treatments, Tmax at 5cm depth is increased by 9-13?C or 11-14?C compared to environment, respectively. Otherwise, Tmax at 10cm depth is increased by 7-9?C compared to environment throughout the second and third week, showing as sensors are able to collect temperature during solarization. The soil microbial community of soils treated with solarization exhibited a slight reduction of cumulative carbon metabolic activity compared to control (8.8% of reduction), while among 31 preselected carbon sources, the soil microbial communities were capable of utilizing up to 23 carbon source without difference between treatments. Unified Modeling Language activity diagrams for solarization management via digital sensors were designed and effects of biodegradable film on microbial population were observed. The integration of information technology solutions with new-generation biodegradable films may offer an interesting revaluation of soil solarization in actual farm organization.

SUMMARY The search for non-chemical methods to control soil-borne pathogens has recently intensified ahead of the forthcoming phase-out of the fumigant methyl bromide in 2005. Indeed, none of the previously available alternatives match methyl bromide wide-spectrum control. Here, we tested two pre-planting treatments: steaming with a soil-steaming machine and exothermic reaction by incorporation into the soil of potassium hydroxide (KOH), a substance that causes an exothermic reaction with water. Experiments were conducted from 2003 to 2005 in open-field conditions by assessing the effectiveness of steam and exothermic reaction against Fusarium oxysporum f.sp. basilici and Sclerotinia minor on basil. The results show that steam combined with exothermic reaction reduce the incidence of Fusarium wilt (77–96%) better than steam only (70–89%). The control of Sclerotinia minor was better with potassium hydroxide (94–92%) than with steam only (83–87%). Further, we evaluated the effects of the treatments on microbial population, yield and weed control. Here, the treatments induced the following major effects: (1) a reduction of more than 99% of the number of Fusarium oxysporum colonies in soil; (2) an increase of about 200% in Trichoderma spp. in soil; (3) a drastic increase in the plant yield, from 6.9–7.5 g for the control to 23.0–25.5 gr for steam treatments; (4) a high reduction of plants per square meter of 94–95% for Amaranthus retroflexus, of 96–99% for Portulaca oleracea, of 93–94% for Chenopodium spp. and of 86–90% for Hordeum vulgare, using both steam and exothermic reactions. Similar results were obtained with steam only. Therefore, our results evidence the potential of this approach to control various soil-borne pathogens. Steam and exothermic reaction are thus promising alternatives to chemical soil disinfestation for high-value crops.

Xylella fastidiosa subsp. pauca strain CoDiRO, a pathogen responsible for Olive Quick Decline Syndrome (OQDS), is strongly threatening the agricultural-based economy of South Italy and making its typical landscape collapse. The bacteria can also infect more than other twenty woody or shrub species and quarantine programs are carried out in Italy. Since symptoms of OQDS like leaf scorching and wilting of canopy may appear several months after infection and some hosts are asymptomatic, a tool for the rapid and early screening of plants is desirable, in order to plan a sudden control strategy and apply programs for pest management. X. fastidiosa detection is usually performed by ELISA and PCR methods. In this work, the two standard methods are compared with an innovative on-chip detection strategy for X. fastidiosa assay from leaves samples, based on an electrochemical transduction method. The realized lab-on-chip includes also a microfluidic module and its performances are competitive with conventional diagnostic methods in terms of reliability, but with further advantages of portability, low-costs and ease of use. Thus, the proposed technology has the potential to provide a useful assay method for large-scale monitoring programs.