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Early blight and ladybug beetle infestation are important factors threatening potato yields. The current research on disease classification using the spectral differences between the healthy and disease-stressed leaves of plants has achieved good progress in a variety of crops, but less research has been conducted on early blight in potato. This paper proposes a CARS-SPA-GA feature selection method. First, the raw spectral data of potato leaves in the visible/near-infrared light region were preprocessed. Then, the feature wavelengths were selected via competitive adaptive reweighted sampling (CARS) and the successive projection algorithm (SPA), respectively. Then, the two sets of wavelengths were reorganized and duplicates were removed, and secondary feature selection was conducted with genetic algorithm (GA). Finally, the feature wavelengths were fed into different classifiers and the parameters were optimized using a real-coded genetic algorithm (RCGA). The experimental results show that the feature wavelengths selected by the CARS-SPA-GA method accounted only for 9% of the full band, and the classification accuracy of the RCGA-optimized support vector machine (SVM) classification model reached 98.366%. These results show that it is feasible to classify early blight and ladybug beetle infestation in potato using visible/near-infrared spectral data, and the CARS-SPA-GA method can substantially improve the accuracy and detection efficiency of potato pest and disease classification. [ABSTRACT FROM AUTHOR]

The tomato-potato psyllid, Bactericera cockerelli (Šulc), belonging to the Hemiptera order, is an insect pest of solanaceous crops and vectors a fastidious bacterium, Candidatus Liberibacter solanacearum (CLso), the presumptive causal agent of zebra chip and vein greening diseases in potatoes and tomatoes, respectively. The genome of B. cockerelli has been sequenced recently, providing new avenues to elucidate mechanistic insights into pathogenesis in vegetable crops. In this study, we performed RNA-sequencing of the critical psyllid organs (salivary glands and ovaries) involved in CLso pathology and transmission to host plants. Transcriptome analysis revealed differentially expressed genes and organ-specific enrichment of gene ontology (GO) terms related to metabolic processes, response to stress/stimulus, phagocytosis, proteolysis, endocytosis, and provided candidate genes encoding transcription factors (TFs). To examine gene regulatory networks across the psyllid organs under CLso(-) and CLso(+) conditions, we performed weighted gene co-expression network analysis (WGCNA), and unique modules differentiating the psyllid organs were identified. A comparative GO analysis of the unique gene modules revealed functional terms enriched in response to stress, gene regulation, and cell division processes in the ovaries. In contrast, respiration, transport, and neuronal transmission-related GO terms were enriched in the salivary glands. Altogether, this study reveals new insights into tissue-specific expression of the psyllid organs in the absence or presence of CLso bacterium. This knowledge can be leveraged to develop new pest and disease management strategies by delineating the regulatory networks involved in the psyllid-CLso interaction. [ABSTRACT FROM AUTHOR]

Disease arises during the storage of potatoes as a result of pathogens introduced during growing and harvest of the tubers. In this study, the causative fungi of domestic potato dry rot disease were identified, and their pathogenicity was confirmed. A total of 76 species were isolated from 93 potato necropods collected from samples inoculated with dry rot disease. These 76 isolates were identified as Fusarium boothii, F. circinatum, F. citricola, F. foetens, F. iranicum, F. longifundum, F. oxysporum, F. pseudoanthophilum, F. solani, Botryotinia ranunculi, Clonostachys rosea, and Humicola nigrescens. The average size of the inoculation site was ≥ 4.6 mm in F. oxysporum and F. solani, which were pathogenic to dry rot in potatoes but were not pathogenic compared to other strains up to 5 weeks in a 15 to 20 °C and 99% RH environment. The pathogenicity of F. foetens and F. pseudoanthophilum was related to a strong relationship by forming a single system with F. oxysporum. However, except for F. oxysporum and F. solani, these strains have not yet been reported to be associated with dry rot disease. Additionally, the length of the cross-section and longitudinal section of the potato damage symptom inoculated with C. rosea increased the most among all strains. This suggests that C. rosea is the dominant species involved in domestic potato dry rot disease. By contrast, there are no reports of the involvement of B. ranunculi and H. nigrescens in dry rot disease. Therefore, these strains can be seen as parasitic using potato sclerosis as nutrients in in vivo experiments through wounds and are not directly related to dry rot disease. [ABSTRACT FROM AUTHOR]

Potato is a very important crop for human nutrition worldwide. Potato disease and pests can cause economic yield losses. In this study, approximately 130.000 potato seeds from different genetic backgrounds were obtained, evaluated, and selected from 2008 to 2016 for developing new cultivars. After several years, superior lines were tested in different locations to select new cultivars. At the end of the potato breeding program, eight superior potato lines (Nos 12-55-07, 12-55-16, 12-68-05, 12-69-39, 13-67-25, 13-66-23, 12-45-24 and 13-66-75) were submitted for registration as commercial cultivars. The use of resistance genes is the most effective method for controlling these diseases and pests, and DNA markers that are tightly linked to resistance genes are available. The aim of this research was to evaluate the use of closely linked molecular markers for combining Gro1 and H1 for cist nematode resistance, Sen1 for wart resistance or with R1 for late blight or with Rx1 for PVX in advanced breeding lines and commercial candidate cultivars. In the research, 61 advanced lines were checked for the presence of five markers. As a result, only two breeding lines (Nos 31-01-03 and 32-02-52) were determined to have positive results for four markers, and nine advanced lines were found to have positive marker results for Sen1, H1, and R1 at the same time. In 6 advanced lines, positive results were acquired from both Sen1, H1, and Rx1, 2 lines Sen1, Gro1, and H1, and only one line No. 12-45-24 Sen1, Gro1, H1, and Rx1 were found to have positive results for markers. Marker-assisted selection for cist nematode, wart, late blight, and PVX will be performed using potato breeding programs. [ABSTRACT FROM AUTHOR]

The tomato potato psyllid, Bactericera cockerelli Šulc, originating from North and Central America, poses a serious threat to Solanaceae crops in Australia. This study investigates the potential of the Australian native and commercially available green lacewing, Mallada signatus Schneider, as a biological control agent for B. cockerelli. The effect of feeding on B. cockerelli on the development rate and survival, of M. signatus were evaluated. Further, a greenhouse cage study was conducted to determine the optimal density of M. signatus larvae needed to effectively control an established B. cockerelli population. In our study, the third instar larvae of M. signatus consumed over 75 B. cockerelli nymphs in 24 h. Following the introduction of M. signatus larvae to caged tomato plants, eight M. signatus larvae per caged tomato plant decreased B. cockerelli population by 64% at the end of the sampling. These results indicated M. signatus, particularly at the larval stage, is an effective biological control option for B. cockerelli, especially in greenhouse tomato cultivation. This research offers valuable insights for the Australian horticultural industry, presenting a viable, eco‐friendly alternative to traditional, chemical pesticide‐reliant pest management strategies. [ABSTRACT FROM AUTHOR]

Potatoes (Solanum tuberosum L.) represent an important food in the country's gastronomy due to their cost, nutritional contribution, and versatility. However, many plant diseases such as the common scab—caused by Streptomyces species—reduce its yield and quality. This study aims to determine Streptomyces species being the causal agent of common scabs in a commercial potato field in the Yaqui Valley, Mexico, while identifying Bacillus strains as a biological control method to mitigate the impact of this disease under field conditions. Thus, three Streptomyces strains were selected from symptomatic samples, and then they were morphologically and molecularly (through sequencing recA and rpoB genes) identified as Streptomyces caniscabiei. After pathogenicity tests, the three strains were found to be pathogenic to potato tubers. In screening assays to identify biocontrol bacteria, strain TSO2T (Bacillus cabrialesii subsp. tritici) and TE3T_UV25 (Bacillus subtilis) had the best in vitro biocontrol effect against S. caniscabiei. Then, a field experiment (1 ha per treatment), under commercial conditions, was carried out to analyze the effectivity of these biocontrol bacteria to mitigate the common scabs on potato crops. After four months, the inoculation of this bacterial consortium decreased common scab incidence from 31% to 21% and increased the potato yield up to almost 5 tons/ha vs. the un-inoculated treatment. These findings demonstrate the effectiveness of the studied bacterial consortium as a potential biological control strategy to control common scabs of potato caused by Streptomyces caniscabiei, as well as increase the potato yield in the Yaqui Valley, Mexico. [ABSTRACT FROM AUTHOR]

The potato is a key crop in addressing global hunger, and deep learning is at the core of smart agriculture. Applying deep learning (e.g., YOLO series, ResNet, CNN, LSTM, etc.) in potato production can enhance both yield and economic efficiency. Therefore, researching efficient deep learning models for potato production is of great importance. Common application areas for deep learning in the potato production chain, aimed at improving yield, include pest and disease detection and diagnosis, plant health status monitoring, yield prediction and product quality detection, irrigation strategies, fertilization management, and price forecasting. The main objective of this review is to compile the research progress of deep learning in various processes of potato production and to provide direction for future research. Specifically, this paper categorizes the applications of deep learning in potato production into four types, thereby discussing and introducing the advantages and disadvantages of deep learning in the aforementioned fields, and it discusses future research directions. This paper provides an overview of deep learning and describes its current applications in various stages of the potato production chain. [ABSTRACT FROM AUTHOR]

The unculturable bacterium 'Candidatus Liberibacter soianacearum' (CLso) is responsible for a growing number of emerging crop diseases. However, we know little about the diversity and ecology of CLso and its psyllid vectors outside of agricultural systems, which limits our ability to manage crop disease and understand the impacts this pathogen may have on wild plants in natural ecosystems. In North America, CLso is transmitted to crops by the native potato psyllid (Bactericera cockerelli). However, the geographic and host plant range of the potato psyllid and CLso beyond the borders of agriculture are not well understood. A recent study of historic herbarium specimens revealed that a unique haplotype of CLso was present infecting populations of the native perennial Solanum umbelliferum in California decades before CLso was first detected in crops. We hypothesized that this haplotype and other potentially novel CLso variants arc still present in S. umbelliferum populations. To test this, we surveyed populations of S'. umbelliferum in Southern California for CLso and potato psyllid vectors. We found multiple haplotypes of CLso and the potato psyllid associated with these populations, with none of these genetic variants having been previously reported in California crops. These results suggest that CLso and its psyllid vectors are much more widespread and diverse in North American natural plant communities than suggested by data collected solely from crops and weeds in agricultural fields. Further characterization of these apparently asymptomatic haplotypes will facilitate comparison with disease-causing variants and provide insights into the continued emergence and spread of CLso. [ABSTRACT FROM AUTHOR]

Late blight, caused by the notorious pathogen Phytophthora infestons, poses a significant threat to potato (Solanum tuberosum) crops worldwide, impacting their quality as well as yield. Here, we aimed to investigate the potential use of cinnamaldéhyde, carvacrol, and eugenol as control agents against P. infestons and to elucidate their underlying mechanisms of action. To determine the pathogen-inhibiting concentrations of these three plant essential oils (PEOs), a comprehensive evaluation of their effects using gradient dilution, mycelial growth rate, and spore germination methods was carried out. Cinnamaldéhyde, carvacrol, and eugenol were capable of significantly inhibiting P. infestons by hindering its mycelial radial growth, zoospore release, and sporangium germination; the median effective inhibitory concentration of the three PEOs was 23.87. 8.66, and 89.65 pl/liter, respectively. Scanning electron microscopy revealed that PEOs caused the irreversible deformation of P. infestons, resulting in hyphal shrinkage, distortion, and breakage. Moreover, propidium iodide staining and extracellular conductivity measurements demonstrated that all three PEOs significantly impaired the integrity and permeability of the pathogen's ceil membrane in a time- and dose-dependent manner. In vivo experiments confirmed the dose-dependent efficacy of PEOs in reducing the lesion diameter of potato late blight. Altogether, these findings provide valuable insight into the antifungal mechanisms of PEOs vis-à-vis late blight-causing P. infestons. By utilizing the inherent capabilities of these natural compounds, we could effectively limit the harmful impacts of late blight on potato crops, thereby enhancing agricultural practices and ensuring the resilience of global potato food production. [ABSTRACT FROM AUTHOR]

Background: The reduced rate of potato production may occur under different conditions such as field, transit, storage, and marketing. Potato cultivation is frequently affected by various pathogens, among which Pectobacterium carotovorum subsp. carotovorum is a notorious bacterial pathogen responsible for causing bacterial soft rot disease. This pathogen poses a significant threat to potato production worldwide, resulting in substantial economic losses and food security concerns. This study aimed to investigate the effectiveness of three bacterial bioagents, namely Brevundimonas bullata, Bacillus siamensis, and Bacillus velezensis, against P. carotovorum subsp. carotovorum, a notorious bacterium responsible for causing potato tuber soft rot disease. Results: Fifteen isolates were isolated from rhizosphere of potato plants. Out of 15 isolates, 3 isolates, No. 1, 11, and 12, showed highly antagonistic property to control the growth of P. carotovorum subsp. carotovorum in vitro. They were identified as B. bullata, B. velezensis, and B. siamensis, by using 16S rRNA nucleotide sequence analysis. Results from these experiments revealed that three bioagents exhibited notable inhibitory effects on the growth of the pathogenic bacterium. However, B. velezensis stood out as the most effective inhibitor among the tested bioagents, showcasing the highest level of bacteriostatic activity (2.6 cm). The findings from the in vitro experiments provided promising insights into the potential of these bacterial bioagents as natural antagonists against potato tuber soft rot disease. Building upon these promising results, the study recommended the utilization of all tested bioagents for controlling soft rot disease in potato tubers, especially during storage conditions where the risk of bacterial proliferation is heightened. Treatment with B. bullata, B. siamensis, and B. velezensis demonstrates varying degrees of efficacy in controlling the progression of soft rot disease. Notably, B. velezensis shows promising results with relatively low disease severity scores across all time points compared to the other treatments. B. velezensis demonstrates the lowest disease severity percentage at 7.00% compared to the other treatments. Conclusions: The study underscores the significant potential of B. bullata, B. siamensis, and B. velezensis as effective biological control agents against potato tuber soft rot disease. By targeting the causative agent directly, these bioagents offer a promising avenue for mitigating the detrimental impact of soft rot disease on potato production, thereby contributing to improved crop yield and quality. [ABSTRACT FROM AUTHOR]

Plant pathogenic Streptomyces species (PPSs) are capable of infecting plant tissues and inducing common scab (CS) in root and tuber crops, with potato common scab (PCS) being the fourth most widespread and damaging disease affecting potato production worldwide. In recent years, with increasing market demand for potato quality, PPSs have garnered significant attention. A thorough understanding of the pathogenic factors of PPSs is a prerequisite for the prevention and control of PCS and can provide targets for the development of PCS control agents. This article primarily summarises the types and damage caused by PPSs, as well as the biosynthesis and molecular regulation of key pathogenic factors, aimed at enhancing our understanding of the molecular pathogenic mechanisms of PPSs and at providing theoretical guidance for the future development of novel PCS control agents. The pathogenicity of PPSs depends predominantly on the phytotoxins, secreted proteins, and phytohormones produced by themselves. Thaxtomins, a group of cyclic dipeptide phytotoxins, are the major pathogenic factors for inhibiting cellulose synthesis in plant tissues and promoting pathogen invasion. Coronafacoyl phytotoxins (CORs) are mainly involved in suppressing plant defence responses, whilst concanamycins (CONs) affect the severity of necrosis in plant pathological tissues. The secreted proteins Nec1 and a homologue of tomatinase TomA inhibit host defence responses, and scabin from the mART family targets guanine in potato DNA, leading to cell apoptosis. Various extracellular enzymes, including glycosyl hydrolases and esterases, are also involved in the pathogenic process of PCS. To put it succinctly, the article mainly takes the pathogenic factors of PPSs as a breakthrough point, so as to fully understand the pathogenic mechanism of PPS molecules, in order to provide a theoretical basis for the future research and control strategies of scab disease. [ABSTRACT FROM AUTHOR]

Recently, every aspect of human existence has been affected by modern technologies, including agriculture. The broad range of crops has witnessed setbacks in different capacities due to climate change, leading to diseases and infections and negatively impacting nutrition. Plant diseases significantly threaten agricultural productivity, leading to substantial economic losses and food insecurity. Traditional methods of disease identification, such as visual inspection and laboratory testing, are time-consuming and require expert knowledge. This study aims to address this problem by leveraging Convolutional Neural Networks (CNNs) and FPGA technology for real-time potato disease identification. Five CNN models were trained and evaluated on the Plant Village dataset, achieving accuracies above 90%. ShuffleNet was identified as the most suitable for FPGA deployment, combining high accuracy with low inference time due to its efficient architecture. The selected CNN was implemented on the Xilinx UltraScale+MPSoC ZCU104 board, demonstrating significant power efficiency with a total consumption of 3.333 W, of which 79% was dynamic power. The design met all timing constraints, ensuring reliable operation at a 100 MHz clock frequency, and exhibited low resource utilization with only 0.20% of LUTs, 0.07% of LUTRAMs, 0.13% of flip-flops, and 0.18% of BUFGs used. These results highlight the FPGA's potential as a power-efficient and high-performance alternative to CPU and GPU implementations for real-time CNN inference. Future work includes developing a test bench for detailed performance measurement, optimizing dynamic power usage, and conducting comparative analyses with other platforms. Additionally, expanding the dataset to include more variability and validating the system in real-world applications will further enhance its effectiveness. This research contributes to the goals of Agriculture 4.0 by providing a viable solution for real-time plant disease identification, ultimately aiming at improving agricultural productivity and food security. [ABSTRACT FROM AUTHOR]

Plant disease detection has played a significant role in combating plant diseases that pose a threat to global agriculture and food security. Detecting these diseases early can help mitigate their impact and ensure healthy crop yields. Machine learning algorithms have emerged as powerful tools for accurately identifying and classifying a wide range of plant diseases from trained image datasets of affected crops. These algorithms, including deep learning algorithms, have shown remarkable success in recognizing disease patterns and early signs of plant diseases. Besides early detection, there are other potential benefits of machine learning algorithms in overall plant disease management, such as soil and climatic condition predictions for plants, pest identification, proximity detection, and many more. Over the years, research has focused on using machine-learning algorithms for plant disease detection. Nevertheless, little is known about the extent to which the research community has explored machine learning algorithms to cover other significant areas of plant disease management. In view of this, we present a cross-comparative review of machine learning algorithms and applications designed for plant disease detection with a specific focus on four (4) economically important plants: apple, cassava, cotton, and potato. We conducted a systematic review of articles published between 2013 and 2023 to explore trends in the research community over the years. After filtering a number of articles based on our inclusion criteria, including articles that present individual prediction accuracy for classes of disease associated with the selected plants, 113 articles were considered relevant. From these articles, we analyzed the state-of-the-art techniques, challenges, and future prospects of using machine learning for disease identification of the selected plants. Results from our review show that deep learning and other algorithms performed significantly well in detecting plant diseases. In addition, we found a few references to plant disease management covering prevention, diagnosis, control, and monitoring. In view of this, little or no work has explored the prediction of the recovery of affected plants. Hence, we propose opportunities for developing machine learning-based technologies to cover prevention, diagnosis, control, monitoring, and recovery. [ABSTRACT FROM AUTHOR]

A study published in the Plant Biotechnology Journal explores the use of genome editing to confer resistance to Candidatus Liberibacter spp. in potatoes. The bacterium causes zebra chip disease, which leads to significant economic losses in the potato industry. The researchers targeted the non-expressor of pathogenesis-related 3 (NPR3) gene in potatoes and successfully edited it using CRISPR-Cas9 technology. The edited potato lines showed reduced disease symptoms, lower pathogen titer, and increased expression of defense-related genes. The study highlights the potential of genome editing as a strategy for developing disease-resistant crops. [Extracted from the article]

Potato soft rot caused by Pectobacterium spp. are devastating diseases of potato which cause severe economic losses worldwide. Pectobacterium brasiliense is considered as one of the most virulent species. However, the virulence mechanisms and pathogenicity factors of this strain have not been fully elucidated. Here, through pathogenicity screening, we identified two Pectobacterium brasiliense isolates, SM and DQ, with distinct pathogenicity levels. SM exhibits higher virulence compared to DQ in inducing aerial stem rot, blackleg and tuber soft rot. Our genomic and transcriptomic analyses revealed that SM encodes strain specific genes with regard to plant cell wall degradation and express higher level of genes associated with bacterial motility and secretion systems. Our plate assays verified higher pectinase, cellulase, and protease activities, as well as fast swimming and swarming motility in SM. Importantly, a unique endoglucanase S specific to SM was identified. Expression of this cellulase in DQ greatly enhances its virulence compared to wild type strain. Our study sheds light on possible determinants causing different pathogenicity of Pectobacterium brasiliense species with close evolutionary distance and provides new insight into the direction of genome evolution in response to host variation and environmental stimuli. [ABSTRACT FROM AUTHOR]

Simple Summary: The tomato bug is a generalist predator commonly used to control insect pests. This exotic mirid was found in 2012 in South Texas and has been established in this region. It was initially observed feeding on nymphs of the potato psyllid in tomato crops. The potato psyllid is the vector of the fastidious bacterium that causes disease in various night-shade crops, including potato zebra chip disease (ZC), with economic losses that by the mid-2000s escalated to tens of millions of dollars in the United States, Mexico, and Central America. We assessed interactions between tomato bugs and potato psyllids in three different environmental settings. First, we estimated the numeric response of tomato bugs preying on potato psyllids under laboratory and greenhouse conditions. Second, we evaluated the predator–prey interaction under controlled field cage conditions. Third, we exposed tomato bugs under controlled field release conditions to the natural occurrence of potato psyllids under a reduced insecticide program. Finally, we assessed its impact on ZC disease incidence, severity in potato tubers, and potato yield. In laboratory and greenhouse experiments, tomato bug response preying resulted in the potentially beneficial effects of the predacious tomato bug reducing potato psyllid populations. Overall, the controlled release of tomato bugs under field conditions significantly reduced potato psyllid incidence in potatoes. Furthermore, the combination of tomato bugs with a reduced insecticide program increased potato yields, but only reduced ZC tuber incidence in one of the two potato cultivars evaluated in one season. Findings from these studies indicate that tomato bugs could be effective as a biological control agent for potato psyllids in potato production. Nesidiocoris tenuis (Hemiptera: Miridae) is a generalist predator commonly used to control the whitefly Bemisia tabaci in Europe. This mirid has been found and established in South Texas, where it was initially observed feeding on nymphs of the psyllid Bactericera cockerelli (Hemiptera: Triozidae) in open tomato fields. B. cockerelli is the vector of the fastidious bacterium "Candidatus Liberibacter solanacearum" that causes diseases in several solanaceous crops, including zebra chip (ZC) disease in potatoes. There is a need to better understand how this predator impacts the control of important crop pests, such as potato psyllids. We assessed the interactions between N. tenuis and B. cockerelli in three different environmental settings. First, we estimated the numeric response of N. tenuis preying on B. cockerelli under laboratory and greenhouse conditions. Second, we evaluated the predator–prey interaction under controlled field cage conditions. Then, we exposed N. tenuis under controlled field release conditions to the natural occurrence of B. cockerelli. Finally, we assessed the compatibility between the use of N. tenuis as a biological control agent in a field study and its impact on ZC disease incidence, severity in potato tubers, and potato yield. Laboratory and greenhouse experiments resulted in diverse types of functional model responses, including exponential and linear mathematical models. Our findings revealed a significant predation effect exerted by N. tenuis, resulting in a reduction of more than fourfold in the number of B. cockerelli nymphs per cage. Specifically, the nymphal population decreased from 21 ± 3.2 in the absence of N. tenuis to 5 ± 1.6 when N. tenuis was present. Furthermore, the combination of N. tenuis with a reduced insecticide program increased potato yields, but only reduced ZC tuber incidence in one of two potato cultivars evaluated, and in one season. Findings from these studies indicate that N. tenuis could be effective as a biological control agent for B. cockerelli in potato production in South Texas. This is the first report of N. tenuis preying on immature stages of any psyllid species. [ABSTRACT FROM AUTHOR]

The threat of emerging plant diseases has become more frequent as global warming and international trade are increasing. Blackleg and soft rot of potatoes caused by the group of bacteria in the family Pectobacteriaceae and the genera Dickeya and Pectobacterium are important diseases causing economic losses globally. In the European Union, they are regulated non‐quarantine pests. Five species are commonly known to cause blackleg symptoms on potatoes indistinguishable from each other. For decades, P. atrosepticum has been the classic seed potato bacterial pathogen in cool temperate climates of Europe and North America, causing blackleg disease. However, recently several new species, unknown in Northern Europe, have emerged as virulent pathogens. One of these species is D. solani. In Finland, D. solani was first found in 2004 and has been the cause of major outbreaks of blackleg in Finland for more than a decade. Currently, its incidence has declined significantly because of a stringent, concerted engagement strategy adopted to combat the pathogen that is described in detail in this article. This strategy implemented in Finland could serve as a model system to combat other emerging and re‐emerging species of Dickeya and Pectobacterium and serve as useful support information for the formulation of a policy framework for the management of emerging plant health risks. [ABSTRACT FROM AUTHOR]

Potato black scurf, caused by Rhizoctonia solani, is a severe soil-borne disease that affects the quality and production of potatoes worldwide. In our study, we used Paenibacillus polymyxa YF and Bacillus amyloliquefaciens HT to determine the antagonistic ability of R. solani, with a particular focus on the antagonistic action of P. polymyxa YF to R. solani and its biocontrol effect on potato black scurf. In fermentation, filtrate assay, 50% filtrate of P. polymyxa YF and B. amyloliquefaciens HT inhibited the growth of R. solani by 85.55% and 82.86%, respectively. Microscopic observations showed notable morphological changes with mycelial collapse, atrophy, and deformation following treatment with the antagonistic filtrates. Moreover, cell membrane permeability results showed increased conductivity in bacteria-treated samples compared to the control. P. polymyxa YF exhibited stable colonization on potato plants and secreted various extracellular enzymes (protease, amylase, and cellulase), along with the synthetic substances with growth-promoting effects, such as siderophores and Indole-3-acetic acid (IAA). Whether it is in the excised tissue inoculation or potted experiment, the negative control showed the highest rank of disease symptoms. In the pot experiment, after YF treatment, physiological parameters showed remarkable changes in plant height, root length, stem thickness, and dry and fresh weight. Compared to blank control, the activities of the four resistant enzymes increased significantly in the P. polymyxa YF treatment group. The upregulation in the P. polymyxa YF group was 4.04, 0.54, 0.46, and 3.10 times, respectively. PCR analysis identified genes in both bacterial strains coding for antimicrobial lipopeptides, including fenB, ituC, and srfAA, which are associated with fengycin, iturin, and surfactin synthesis. These findings demonstrated that P. polymyxa YF has a prominent antagonistic effect on R. solani, suggesting its potential as an effective biological control agent for controlling potato black scurf. [ABSTRACT FROM AUTHOR]

This document provides the conclusions of the pest survey card that was prepared in the context of the EFSA mandate on plant pest surveillance (M‐2020‐0114) at the request of the European Commission. The full pest survey card for the members of the Andean Potato Weevil (APW) complex is published and available online in the EFSA Pest Survey Card gallery at the following link and will be updated whenever new information becomes available: https://efsa.europa.eu/plants/planthealth/monitoring/surveillance/andean-potato-weevil-complex [ABSTRACT FROM AUTHOR]

Introduction: The potato psyllid Bactericera cockerelli is the insect vector of the fastidious bacterium 'Candidatus Liberibacter solanacearum'. The bacterium infects both B. cockerelli and plant species, causing zebra chip (ZC) disease of potato and vein-greening disease of tomato. Temperatures are known to influence the initiation and progression of disease symptom in the host plant, and seasonal transitions from moderate to high temperatures trigger psyllid dispersal migration to facilitate survival. Methods: 'Ca. L. solanacearum' -infected and uninfected psyllids were reared at previously established 'permissible', optimal, and'non-permissible' and temperatures of 18°C, 24°C, and 30°C, respectively. Gene expression profiles for 'Ca. L. solanacearum'-infected and -uninfected adult psyllids reared at different temperatures were characterized by Illumina RNA-Seq analysis. Bacterial genome copy number was quantified by real-time quantitative-PCR (qPCR) amplification. Results: Relative gene expression profiles varied in psyllids reared at the three experimental temperatures. Psyllids reared at 18°C and 30°C exhibited greater fold-change increased expression of stress- and 'Ca. L. solanacearum' invasionrelated proteins. Quantification by qPCR of bacterial genome copy number revealed that 'Ca. L. solanacearum' accumulation was significantly lower in psyllids reared at 18°C and 30°C, compared to 24°C. Discussion: Temperature is a key factor in the life history of potato psyllid and multiplication/accumulation of 'Ca. L. solanacearum' in both the plant and psyllid host, influences the expression of genes associated with thermal stress tolerance, among others, and may have been instrumental in driving the coevolution of the pathosystem. [ABSTRACT FROM AUTHOR]

Common scab (CS) is a major bacterial disease causing lesions on potato tubers, degrading their appearance and reducing their market value. To accurately grade scab-infected potato tubers, this study introduces "ScabyNet", an image processing approach combining color-morphology analysis with deep learning techniques. ScabyNet estimates tuber quality traits and accurately detects and quantifies CS severity levels from color images. It is presented as a standalone application with a graphical user interface comprising two main modules. One module identifies and separates tubers on images and estimates quality-related morphological features. In addition, it enables the extraction of tubers as standard tiles for the deep-learning module. The deep-learning module detects and quantifies the scab infection into five severity classes related to the relative infected area. The analysis was performed on a dataset of 7154 images of individual tiles collected from field and glasshouse experiments. Combining the two modules yields essential parameters for quality and disease inspection. The first module simplifies imaging by replacing the region proposal step of instance segmentation networks. Furthermore, the approach is an operational tool for an affordable phenotyping system that selects scab-resistant genotypes while maintaining their market standards. [ABSTRACT FROM AUTHOR]

Potato and coffee crops grapple with pronounced challenges posed by pests, notably the Andean potato weevils (Premnotrypes spp.) and the coffee berry borer (Hypothenemus hampei). These pests inflict significant economic repercussions on both smallholder and commercial farmers by disrupting essential food supply chains. This review delves into the insecticidal potentials of botanical resources against these pests. Notably, extracts and essential oils (EOs) from native flora or commercially available in each affected country have compelled efficacy against Premnotrypes vorax, P. latithorax and Hypothenemus hampei, such as Schinus molle L. and Schinus terebinthifolia Raddi, respectively. Through rigorous laboratory tests, onsite evaluations, and cost-effectiveness assessments, there emerges a strong advocacy for these botanical solutions. They present not only a sustainable countermeasure to these pests but also a greener alternative to conventional pesticides, thereby potentially reducing the environmental degradation and health concerns synonymous with chemical pesticides. The shift towards natural pesticides, especially those derived from plants like S. molle and S. terebinthifolia, is not only environmentally strategic but also economically prudent, aligning with both market trends and long-term sustainability goals. [ABSTRACT FROM AUTHOR]

Potato diseases and pests have a serious impact on the quality and yield of potatoes, and timely prevention and control of potato diseases and pests is essential. A rich knowledge reserve of potato diseases and pests is one of the most important prevention and control measures; however, valuable knowledge is buried in the massive data of potato diseases and pests, making it difficult for potato growers and managers to obtain and use it in a timely manner and to develop the potential of knowledge. Therefore, this paper explores the construction method of a knowledge graph for automatic knowledge extraction, which extracts the knowledge of potato diseases and pests scattered in heterogeneous data from multiple sources, organises it into a semantically related knowledge base, and provides potato growers with professional knowledge and timely guidance to effectively prevent and control potato diseases and pests. In this paper, a data corpus on potato diseases and pests, called PotatoRE, is first constructed. Then, a model of ALBert-BiLSTM-Self_Att-CRF is designed to extract knowledge from the corpus to form a triplet structure, which is imported into the Neo4j graph database for storage and visualisation. Furthermore, the performance of the model constructed in this paper is compared and verified using the datasets PotatoRE and People's Daily. The results show that compared to the SOTA models of ALBert BiLSTM-CRF and ALBert BiGRU-CRF, the accuracy of our model has been improved by 2.92% and 3.12%, respectively, using PotatoRE. Compared to the Bert BiLSTM-CRF model on two datasets, our model not only improves the accuracy, recall, and F1 values, but also has a higher efficiency. The model in this paper solves the problem of the difficult recognition of nested entities. On this basis, through comparative experiments, the TransH model is used to effectively represent the constructed knowledge graph, which lays the foundation for achieving inference, extension, and automatic updating of the knowledge base. The achievements of the thesis have made certain contributions to the automatic construction of large-scale knowledge bases. [ABSTRACT FROM AUTHOR]

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Potato silver scurf, caused by the fungus Helminthosporium solani, is an important storage disease of potato (Solanum tuberosum L.), reducing the market value of tubers. Using in vitro and in vivo assays, the presented experiments aimed to determine the effect of selected essential oils (EOs: α-pinene, carvacrol, cinnamaldehyde, D-carvone, eucalyptol, L-linalool, L-menthol, L-menthone, (R)-(+)-limonene, and thymol) on H. solani growth. All EOs inhibited pathogen growth, but their antifungal activities differed significantly. Thymol, carvacrol, and cinnamaldehyde had the strongest inhibitory effects on mycelial growth under in vitro conditions. (R)-(+)-limonene displayed the weakest inhibition. The effectiveness of those EOs with the greatest antifungal activity was confirmed by in vivo experiments. EOs were applied through dressing and fumigation, with EOs bound to a biopolymer for dressing. Dressing and fumigation brought a highly statistically significant reduction in H. solani infection intensity and sporulation intensity on tubers. Although EOs had an insignificant effect on potato cooking quality, the taste of EO-dressed tubers was degraded by an off-odor and off-taste. EOs could provide an ecological alternative for reducing H. solani tuber infection during storage. [ABSTRACT FROM AUTHOR]

Dry rot of potatoes is caused by several fungal species in the genus Fusarium, of which Fusarium solani is an outstanding cause of postharvest potato losses globally. The fungus can also cause a broad spectrum of infections in humans and animals. The dry rot disease spread in the potato field has been treated mainly using fungicides that are very harmful to human health. The use of fungicides also pollutes the living environment and unbalances the microbial ecosystems in nature. Streptomyces flaveus has been known to produce antibiotic SW-B capable of inhibiting the growth of several plant pathogenic fungi. However, it has not been clear whether S. flaveus is able to inhibit the growth of F. solani. This study isolated the fungus that caused the potato dry rot from the diseased potato tubers and evaluated the antifungal activity of S. flaveus against the isolated fungus. Cell morphology and phylogenetic analyses of the fungus showed that F. solani was successfully isolated. It was found that this fungal isolate was sensitive to S. flaveus. This actinomycete produced extracellular chitinase whose concentration in the liquid culture was affected by the supplementation of colloidal chitin and fungal cell powder into the culture medium, making the F. solani mycelial cell an important factor for optimizing chitinase concentration in biocontrol preparation for prevention and treatment of the dry rot disease in potato tubers. [ABSTRACT FROM AUTHOR]

Black scurf and stem canker caused by Rhizoctonia solani is a significant disease problem of potatoes. Currently, chemical methods are the primary means of controlling this pathogen. This study sought to explore an alternative approach by harnessing the biocontrol potential of a bacterial mix of Bacillus subtilis and Bacillus amyloliquefaciens against black scurf, and to determine their effect on rhizosphere microorganisms of soil microbiota. This study showed that these bacteria demonstrate antagonistic activity against Rhizoctonia solani. Reduced damage to potato plants during the growing season in Siberia was observed. The index of disease development decreased from 40.9% to 12.0%. The treatment of tubers with this mix of bacteria also led to a change in the composition of the rhizosphere microbiota (according to CFU, 16S and ITS sequencing). This effect was accompanied by a positive change in plant physiological parameters (spectrophotometric analysis). The concentration of chlorophyll in potatoes with the bacterial mix treatment increased by 1.3 fold (p ≤ 0.001), and of carotenoids by 1.2 fold (p ≤ 0.01) compared with the control. After bacterial mix treatment, the length of the aerial parts of plants was 1.3 fold higher (p ≤ 0.001), and the number of stems 1.4 fold higher (p ≤ 0.05). The yield of potatoes was increased by 8.2 t/ha, while the large tuber fraction was increased by 16% (p ≤ 0.05). The bacteria mix of Bacillus subtilis and Bacillus amyloliquefaciens suppressed the plant pathogenic fungus Rhizoctonia solani, and simultaneously enhanced the physiological parameters of potato plants. This treatment can be used to enhance the yield/quality of potato tubers under field conditions. [ABSTRACT FROM AUTHOR]

Background: Enterobacter cloacae is a bacterium that leads to soft rot in many diverse types of vegetables & crops across the world. At this time nanotechnology is utilized as a nanomaterials strategy for controlling plant pathogenic bacteria and maintaining postharvest quality. Methods: The soft rotten tissues were collected from infected potato tuber and macerated in buffer saline solution. 50 uL of macerated sap was inoculated on selective King, B medium for isolated pathogenic bacteria. PCR was utilized to identify the isolated bacteria according to their morphology and the 16S rRNA gene. A randomized complete design was applied in the protective by Ch-MSNPs20nm@HTCC in postharvest. Results: Typical colonies on King, B medium were circular, moist, smooth, and entire margin, flat and fluorescent diffusible pigment in medium that identify Enterobacter sp. As well as phylogenetically it identified Ent. cloacae based on 16s RNA gene. Ch-MSNPs20nm @HTCC sprayed on infected potato tubers postharvest significantly reduced the disease severity, lowest HBS and AUDPC values and increased weight of healthy tuber tissues compared with Ampicillin as a positive control. In addition, it has the ability to prevent isolated Ent. cloacae from forming a biofilm. On the other hand, it has efficacy in increasing the longevity of potato tubers at postharvest. [ABSTRACT FROM AUTHOR]

More than 170 years after causing the potato famine in Ireland, late blight is still considered one of the most devastating crop diseases. Commercial potato breeding efforts depend on natural sources of resistance to protect crops from the rapidly evolving late blight pathogen, Phytophthora infestans. We have identified and mapped a novel broad-spectrum disease resistance gene effective against P. infestans from the wild, diploid potato species Solanum bulbocastanum. Diagnostic resistance gene enrichment sequencing (dRenSeq) was used to confirm the uniqueness of the identified resistance. RenSeq and GenSeq-based mapping of the resistance, referred to as Rpi-blb4, alongside recombinant screening, positioned the locus responsible for the resistance to potato chromosome 5. The interval spans approximately 2.3 Mb and corresponds to the DM reference genome positions of 11.25 and 13.56 Mb. [ABSTRACT FROM AUTHOR]

Potato is one of the most important crops worldwide, and its productivity can be affected by various diseases, including leaf diseases. Early detection and accurate diagnosis of leaf diseases can help prevent their spread and minimize crop losses. In recent years, Convolutional Neural Networks (CNNs) have shown great potential in image classification tasks, including disease detection in plants. In this study, we propose a CNN-based approach for the prediction of potato leaf diseases. The proposed method uses a pre-trained CNN model, which is fine-tuned on a dataset of potato leaf images. The dataset includes images of healthy leaves and leaves infected with different diseases such as early blight and late blight. The trained model is then used to classify new images of potato leaves into healthy or diseased categories. The proposed approach achieves 97.4% accuracy in the classification of potato leaf diseases such as early blight potato leaf disease and late blight potato leaf disease, and can be used as an effective tool for early detection and management of these diseases in potato crops. [ABSTRACT FROM AUTHOR]

BACKGROUND: As a highly prevalent epidemic disease of potato, late blight caused by Phytophthora infestans poses a serious threat to potato yield and quality. At present, chemical fungicides are mainly used to control potato late blight, but long‐term overuse of chemical fungicides may lead to environmental pollution and human health threats. Endophytes, natural resources for plant diseases control, can promote plant growth, enhance plant resistance, and secrete antifungal substances. Therefore, there is an urgent need to find some beneficial endophytes to control potato late blight. RESULTS: We isolated a strain of Bacillus subtilis H17‐16 from potato healthy roots. It can significantly inhibit mycelial growth, sporangia germination and the pathogenicity of Phytophthora infestans, induce the resistance of potato to late blight, and promote potato growth. In addition, H17‐16 has the ability to produce protease, volatile compounds (VOCs) and form biofilms. After H17‐16 treatment, most of the genes involved in metabolism, virulence and drug resistance of Phytophthora infestans were down‐regulated significantly, and the genes related to ribosome biogenesis were mainly up‐regulated. Moreover, field and postharvest application of H17‐16 can effectively reduce the occurrence of potato late blight, and the combination of H17‐16 with chitosan or chemical fungicides had a better effect than single H17‐16. CONCLUSION: Our results reveal that Bacillus subtilis H17‐16 has great potential as a natural fungicide for controlling potato late blight, laying a theoretical basis for its development as a biological control agent. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background: Due to the soilborne and tuber-borne nature of their causative agents, Fusarium wilt, Rhizoctonia root canker and black dot diseases are still leading to serious problems in potato production in Tunisia and worldwide. Among endophytic bacteria, the genus Bacillus is one of the most exploited microbial groups known as potent biocontrol agents against several potato diseases. In the present study, six strains belonging to five Bacillus species were screened for their abilities to inhibit root and wilt potato pathogens in vitro, in vivo and under natural conditions over three cropping seasons and to promote plant growth. Results: Based on the dual-culture assays, the whole-cell suspensions of SV39 and SV104 (Bacillus tequilensis), SV41 (B. subtilis), SV44 (B. methylotrophicus) and SV65 (B. amyloliquefaciens subsp. plantarum) strains exhibited potent antifungal activity against important potato soilborne phytopathogens with ~ 65 to 70% inhibition rates. Significant inhibition rates were also induced by the cell-free culture filtrates, the butanolic and the chloroformic extracts depending on the target pathogens, the concentration used and the Bacillus strain tested. In pot experiment, a decrease in Rhizoctonia root canker severity, ranging from 43 to 65% compared to the inoculated and untreated control, was induced by all Bacillus spp. strain-based treatments, while SV39-, S42- and SV65-based treatments were the most effective in suppressing by 50–53 and 65–52%, black dot severity and the relative vascular discoloration extent induced by F. oxysporum f. sp. tuberosi, respectively, relative to positive control. This biocontrol potential was associated with an enhancement of potato growth parameters. Field studies indicated that soil treatment with the most of the Bacillus spp. strains had significantly controlled all the target fungal soilborne diseases and improved at the least two growth and/or production parameters depending on the strain used and the cropping seasons. SV39-, SV41-, SV44- and SV104-based treatments resulted in a significant increase in tuber yield in one cropping season. Conclusion: These Bacillus spp. strains could be used in combinations and/or introduced with other existing practices in order to provide supplemental control of target diseases and yield promotion under organic or conventional potato production systems. [ABSTRACT FROM AUTHOR]

Potato is one of the highly consumed vegetable crop grown in different regions across Pakistan that is affected by fungal diseases. The current research was conducted to identify fungal pathogen causing mold-like disease of potato in Khyber Pakhtunkhwa (KP), Pakistan. For molecular identification and characterization of the fungal disease; potato tuber samples were collected followed by culturing on potato dextrose agar (PDA). Based on morphological features, the pathogen was identified as a Penicillium species. This result was obtained in 45 different isolates from potato tubers. Molecular identification was done using β-tubulin primers and ITS5 sequencing of 13 different isolates that releveled 98% homology with BLAST (GenBank accession no. KX958076) as Penicillium solitum (GenBank accession nos. ON307317; ON307475 and ON310801). Phylogenetic tree was constructed that showed Penicillium solitum prevalence along with Penicillium polonicum and Penicillium citrinum on potato tubers. Based on this, Penicillium solitum based silver nanoparticles (Ag NPs) were synthesized and characterized using UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX) and field emission scanning electron microscopy (FE SEM). UV-analysis showed a characteristic peak at 410 nm confirming synthesis of Penicillium solitum based Ag NPs. This was further confirmed by XRD followed by EDX and SEM that showed face cubic crystal structure with Ag as major constituent of 18 nm formed spherical Ag NPs. FTIR showed band stretching of O-H, N-O and C-H of biological origin. Similarly, Penicillium solitum based Ag NPs presented strong anti-bacterial and anti-fungal activity at 0.5 level of significance LSD. According to our knowledge, this is the first report of Penicillium solitum identification in Pakistan, its Ag NPs synthesis and characterization to be used against pathogens of agricultural significance. [ABSTRACT FROM AUTHOR]

Black scurf disease on potato caused by Rhizoctonia solani AG3 occurs worldwide and is difficult to control. The use of potato cultivars resistant to black scurf disease could be part of an integrated control strategy. Currently, the degree of resistance is based on symptom assessment in the field, but molecular measures could provide a more efficient screening method. We hypothesized that the degree of field resistance to black scurf disease in potato cultivars is associated with defense-related gene expression levels and salicylic acid (SA) concentration. Cultivars with a moderate and severe appearance of disease symptoms on tubers were selected and cultivated in the same field. In addition, experiments were conducted under controlled conditions in an axenic in vitro culture and in a sand culture to analyze the constitutive expression of defense-related genes and SA concentration. The more resistant cultivars did not show significantly higher constitutive expression levels of defense-related genes. Moreover, the level of free SA was increased in the more resistant cultivars only in the roots of the plantlets grown in the sand culture. These results indicate that neither expression levels of defense-related genes nor the amount of SA in potato plants can be used as reliable predictors of the field resistance of potato genotypes to black scurf disease. [ABSTRACT FROM AUTHOR]

In the present study, bacterial endophytes were obtained from weeds of potato fields. Their antagonistic activity was screened against potato storage pathogen, Pectobacterium carotovorum subsp. carotovorum (Pcc) (JX029052), in the maceration assay. An endophytic strain, PC-2B was isolated from Convolvulus arvensis L. as a dominant weed of potato fields. In vivo application of this strain led to 58.8% reduction in tuber decay. This motile strain that can produce amylase was identified as Pantoea sp. using phenotypic features and 16S rRNA sequencing. Following PC-2B treatment, 56.7% Reduction in Disease Incidence (RDI) was obtained in preventative and 52% in curative challenges under semi-practical storage trails. Anti-Pcc bioactive compounds of Pantoea sp. was extracted and identified based on H NMR and FT-IR techniques. Two peptide antibiotics including Pantocin A and B with inhibitory effect against Pcc were characterized. These results might indicate that the tested Pantoea strain could be a promising candidate to protect potato tubers against soft rot disease caused by Pcc. However, large-scale complementary trials have to be conducted to validate these results before any recommendations. [ABSTRACT FROM AUTHOR]

Background: The psyllid, Bactericera cockerelli, is an insect vector of 'Candidatus Liberibacter' causing "Zebra chip" disease that affects potato and other Solanaceae crops worldwide. In the present study, we analyzed the bacterial communities associated with the insect vector Bactericera cockerelli central haplotype of tomato crop fields in four regions from Mexico. Methods: PCR was used to amplify the mitochondrial cytochrome oxidase I gene (mtCOI) and then analyze the single nucleotide polymorphisms (SNP) and phylogenetic analysis for haplotype identification of the isolated B. cockerelli. Moreover, we carried out the microbial diversity analysis of several B. cockerelli collected from four regions of Mexico through the NGS sequencing of 16S rRNA V3 region. Finally, Wolbachia was detected by the wsp gene PCR amplification, which is the B. cockerelli facultative symbiont. Also we were able to confirm the relationship with several Wolbachia strains by phylogenetic analysis. Results: Our results pointed that B. cockerelli collected in the four locations from Mexico (Central Mexico: Queretaro, and Northern Mexico: Sinaloa, Coahuila, and Nuevo Leon) were identified, such as the central haplotype. Analyses of the parameters of the composition, relative abundance, and diversity (Shannon index: 1.328 ± 0.472; Simpson index 0.582 ± 0.167), showing a notably relatively few microbial species in B. cockerelli. Analyses identified various facultative symbionts, particularly the Wolbachia (Rickettsiales: Anaplasmataceae) with a relative abundance higher. In contrast, the genera of Sodalis and 'Candidatus Carsonella' (Gammaproteobacteria: Oceanospirillales: Halomonadaceae) were identified with a relatively low abundance. On the other hand, the relative abundance for the genus 'Candidatus Liberibacter' was higher only for some of the locations analyzed. PCR amplification of a fragment of the gene encoding a surface protein (wsp) of Wolbachia and phylogenetic analysis corroborated the presence of this bacterium in the central haplotype. Beta-diversity analysis revealed that the presence of the genus 'Candidatus Liberibacter' influences the microbiota structure of this psyllid species. Conclusions: Our data support that the members with the highest representation in microbial community of B. cockerelli central haplotype, comprise their obligate symbiont, Carsonella, and facultative symbionts. We also found evidence that among the factors analyzed, the presence of the plant pathogen affects the structure and composition of the bacterial community associated with B. cockerelli. [ABSTRACT FROM AUTHOR]

The Phthorimaea operculella Zeller moth is a pest that affects potato crops and is found mainly in the inter-Andean valleys of the highlands of Peru (Huancavelica). The objective of the research was to use the phenomenon of light generated by light-emitting diodes (LEDs) to attract the potato moth in storage. Every day at seven o'clock in the morning, the number of moths falling dead in the light trap on the water contained in the container was counted. Five LED lights with different light densities per square centimeter were tested for five nights with different frequencies: 3.125 Hz, 12.5 Hz, 50 Hz, 200 Hz and 400 Hz. Every five nights the operating current of the LEDs was changed: 5 mA, 10 mA and 15 mA. Every fifteen nights the color of the LEDs was changed, according to the following sequence: white, blue, green, yellow and red; the color that attracted the most was white light, while the one with the least attraction was red light. The white light trap using the 64 LED array attracted 38.73% of moths and consumed a total of 43 W of energy in seven days, so it is considered low energy consumption. [ABSTRACT FROM AUTHOR]

This article discusses a study that examined the effectiveness of six native Trichoderma species as biocontrol agents against Alternaria solani, a pathogen that causes early blight in tomatoes. The study found that all of the Trichoderma species tested were able to significantly inhibit the growth of A. solani, with T. harzianum being the most effective. The results suggest that Trichoderma species could be used as a natural alternative to pesticides for managing A. solani and reducing the impact of early blight on tomato crops. This research provides valuable insights for the use of biological agents in potato disease management. [Extracted from the article]

RT-PCR was used to test whether DNA from potato psyllid (Bactericera cockerelli (Šulc)) could be detected in generalist predators that had been allowed to feed on psyllids in laboratory feeding trials. The assay used primers that had been developed in Europe to amplify a region of the ITS2 gene in psyllids for use in identifying psyllid specimens intercepted at border inspection stations or discovered in regions currently free of the pest. We conducted feeding trials with arthropod generalist predators in diverse taxonomic groups (Araneae, Acari, and two orders of Insecta). RT-PCR readily detected potato psyllid DNA in predators that had recently fed upon the insect. DNA from a closely related psyllid, Bactericera dorsalis (Crawford), was not detected, suggesting that our approach is unlikely to lead to false positives. RT-PCR was found to be more sensitive than conventional PCR at detecting very dilute quantities of potato psyllid DNA. Predator taxa differed in how long after a feeding event prey DNA could be detected. Signal retention was longer in spiders and a predatory mite (Anystis) than in predatory true bugs (Hemiptera). We believe this new molecular tool will be of value in identifying potentially important sources of psyllid biological control under field conditions. [ABSTRACT FROM AUTHOR]

Potato downy mildew is a disease caused by a fungus called Phytophthora infestans (Mont.) de Bary, which is mainly seen in potatoes and tomatoes, but also in other culture and wild plants belonging to the Solanaceae family. This fungus is quite important both from an economic and historical point of view. In case of an epidemic, it can cause full crop deterioration or serious losses in potatoes. Although cultural and chemical control methods are generally used in the control of the disease, there is no specific biological control method in this regard. Entomopathogenic fungi (EPFs) are generally used as biological control agents in the control of insect pests. Recently, there are many studies showed that these fungi can live endophytically on various cultivated plants and provide beneficial properties to the plants they live with. In this study, it was aimed to determine the in vitro antagonistic activities of different entomopathogenic fungi previously isolated from potato fields and identified by molecular methods against P. infestans. Earlier work determined that these fungi had a lethal effect on Leptinotarsa decemlineata (Say, 1824). Antagonistic activity tests were performed according to the "direct opposition method" and percentage (%) activity values were calculated. As a result of the tests, the most effective isolates were found to be Beauveria sp. SK-14 (75.23%) and Metarhizium sp. SK-24 (76.23%). It is thought that the results obtained will contribute to the biocontrol of diseases and pests in potatoes. [ABSTRACT FROM AUTHOR]

Aims: This study was aimed to analyze the antagonistic ability of Pantoea sp. against Ralstonia solanacearum, which causes bacterial wilt in potato plants and to analyze the antimicrobial compounds produced by the antagonistic bacteria. Methodology and results: Pantoea sp. was isolated from the rhizosphere of healthy potato plants in Taman Tanda village, Baturiti, Tabanan, Bali. The diffusion well method tested the isolates' antagonistic ability against R. solanacearum. The Pantoea sp., which showed the best inhibition zone was then identified morphologically, biochemically and molecularly using 16S rDNA gene sequencing and its analysis. Five isolates of Pantoea sp. were isolated from the rhizosphere of potato plants. Pantoea sp. 4 showed the best inhibition against R. solanacearum and was identified as Pantoea agglomerans. Filtrate of P. agglomerans was tested against R. solanacearum to analyze the inhibition ability. The minimum inhibitory concentration (MIC) value of the P. agglomerans filtrate was 6%. Fraction 10 of P. agglomerans filtrate showed the highest inhibition zone (17 mm). The active compounds of fraction 10 characterized as antimicrobial were decamethyl tetrasiloxane, hexamethylcyclotrisiloxane, 2,4-dimethyl Benzo[h]quinoline and arsenous acid. Conclusion, significance and impact of study: Pantoea agglomerans isolated from potato rhizosphere in Baturiti, Bali, have the potential as an antagonist agent against R. solanacearum that causes bacterial wilt. The active compound produced by P. agglomerans can act as an antibacterial against the pathogen R. solanacearum. Pantoea agglomerans culture can be used as a biocontrol agent against R. solanacearum. [ABSTRACT FROM AUTHOR]

Potato Verticillium wilt, caused by Verticillium dahliae, is a serious soil-borne vascular disease, which restricts the sustainable development of the potato industry, and the pathogenic mechanism of the fungus is complex. Therefore, it is of great significance to explore the important pathogenic factors of V. dahliae to expand the understanding of its pathology. Protein kinase C (PKC) gene is located in the Ca2+ signaling pathway, which is highly conserved in filamentous fungi and involved in the regulation of a variety of biological processes. In the current study, the PKC gene in V. dahliae (VdPKC) was characterized, and its effects on the fungal pathogenicity and tolerance to fungicide stress were further studied. The results showed that the VdPKC positively regulated the growth and development, conidial germination, and production of V. dahliae, which was necessary for the fungus to achieve pathogenicity. It also affected the formation of melanin and microsclerotia and changed the adaptability of V. dahliae to different environmental stresses. In addition, VdPKC altered the tolerance of V. dahliae to different fungicides, which may be a potential target for polyoxin. Therefore, our results strongly suggest that VdPKC gene is necessary for the vegetative growth, stress response, and pathogenicity of V. dahliae. [ABSTRACT FROM AUTHOR]

The white potato worm Premnotrypes vorax (Hustache) (Coleoptera: Curculionidae) is one of the most destructive insect pests of potato crops in South America. Like many coleopteran insects, P. vorax shows low susceptibility to Cry insecticidal proteins produced by the bacterium Bacillus thuringiensis (Bt). However, the presence of Cry toxin receptors in the midgut of this this insect has never been studied. The main Cry-binding proteins described in other insect species are cadherin (CAD), aminopeptidase N (APN), alkaline phosphatase (ALP) and ATP-binding cassette (ABC) transporters. In this study, we analyzed and validated a de novo assembled transcriptome of Illumina sequencing data to identify and to characterize homologs of Cry toxin receptors. We identified the protein sequences in P. vorax that show high identity with their orthologous sequences of the Cry toxin binding proteins in other coleopteran larvae such as APN, ALP, CAD and ABC transporter. This study provides preliminary identification of putative receptor genes of Cry proteins that would be useful for future studies involving biocontrol of this important potato crop pest. [ABSTRACT FROM AUTHOR]

Aims Black scurf disease, caused by Rhizoctonia solani , is a severe soil-borne and tuber-borne disease, which occurs and spreads in potato growing areas worldwide and poses a serious threat to potato production. New biofungicide is highly desirable for addressing the issue, and natural products (NPs) from Xenorhabdus spp. provide prolific resources for biofungicide development. In this study, we aim to identify antifungal NPs from Xenorhabdus spp. for the management of this disease. Methods and results Out of the 22 Xenorhabdus strains investigated, Xenorhabdus budapestensis 8 (XBD8) was determined to be the most promising candidate with the measured IC50 value of its cell-free supernatant against R. solani as low as 0.19 ml l−1. The major antifungal compound in XBD8 started to be synthesized in the middle logarithmic phase and reached a stable level at stationary phase. Core gene deletion coupled with high-resolution mass spectrometry analysis determined the major antifungal NPs as fabclavine derivatives, Fcl-7 and 8, which showed broad-spectrum bioactivity against important pathogenic fungi. Impressively, the identified fabclavine derivatives effectively controlled black scurf disease in both greenhouse and field experiments, significantly improving tuber quality and increasing with marketable tuber yield from 29 300 to 35 494 kg ha−1, comparable with chemical fungicide fludioxonil. Conclusions The fabclavine derivatives Fcl-7 and 8 were determined as the major antifungal NPs in XBD8, which demonstrated a bright prospect for the management of black scurf disease. [ABSTRACT FROM AUTHOR]

BACKGROUND: By expressing double‐stranded RNA (dsRNA) in potato plastids targeting the β‐Actin (ACT) gene of the Colorado potato beetle (CPB), transplastomic plants can trigger the beetle's RNA interference response to kill the CPB larvae. High expression of dsACT driven by rrn16 promoter (Prrn) in the leaf chloroplasts of transplastomic plants confers strong resistance to CPB. However, there are still residual amounts of dsRNA in the tubers, which are unnecessary for CPB control and may raise a potential food exposure issue. RESULTS: In order to reduce dsRNA accumulation in the tubers while maintaining stable resistance to CPB, we selected two promoters (PrbcL and PpsbD) from potato plastid‐encoded rbcL and psbD genes and compared their activities with Prrn promoter for dsRNA synthesis in the leaf chloroplasts and tuber amyloplasts. We found that the dsACT accumulation levels in leaves of transplastomic plants St‐PrbcL‐ACT and St‐PpsbD‐ACT were significantly reduced when compared to St‐Prrn‐ACT, but they still maintained high resistance to CPB. By contrast, a few amounts of dsACT were still accumulated in the tubers of St‐PrbcL‐ACT, whereas no dsACT accumulation in tubers was detectable in St‐PpsbD‐ACT. CONCLUSION: We identified PpsbD as a useful promoter to reduce dsRNA accumulation in potato tubers while maintaining the high resistance of the potato leaves to CPB. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO-NPs) have gained significant attention in nanotechnology due to their unique properties and potential applications in various fields, including insecticidal and antibacterial activities. The ZnO-NPs were biosynthesized by Eriobotrya japonica leaf extract and characterized by various techniques such as UV–visible (UV–vis) spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential analysis. The results of SEM revealed that NPs were irregular and spherical-shaped, with a diameter between 5 and 27 nm. Meanwhile, DLS supported that the measured size distributions were 202.8 and 94.7 nm at 11.1° and 90.0°, respectively, which supported the polydisperse nature of NPs, and the corresponding zeta potential was −20.4 mV. The insecticidal activity of the produced ZnO-NPs was determined against the adult stage of coleopteran pests, Sitophilus oryzae (Linnaeus) (Curculionidae) and Tribolium castaneum (Herbst) (Tenebrionidae). The LC50 values of ZnO-NPs against adults of S. oryzae and T. castaneum at 24 h of exposure were 7125.35 and 5642.65 μg/mL, respectively, whereas the LC90 values were 121,824.56 and 66,825.76 μg/mL, respectively. Moreover, the biosynthesized nanoparticles exhibited antibacterial activity against three potato bacterial pathogens, and the size of the inhibition zone was concentration-dependent. The data showed that the inhibition zone size increased with an increase in the concentration of nanoparticles for all bacterial isolates tested. The highest inhibition zone was observed for Ralstonia solanacearum at a concentration of 5 µg/mL, followed by Pectobacterium atrosepticum and P. carotovorum. Eventually, ZnO-NPs could be successfully used as an influential agent in pest management programs against stored-product pests and potato bacterial diseases. [ABSTRACT FROM AUTHOR]

Phytophthora infestans is, worldwide, one of the main causal agents of epiphytotics in potato plantings. Prevention strategies demand integrated pest management, including modeling of beneficial microbiomes of agroecosystems combining microorganisms and natural products. Chitooligosaccharides and their derivatives have great potential to be used by agrotechnology due to their ability to elicit plant immune reactions. The effect of combining Bacillus subtilis 26D and 11VM and conjugates of chitin with hydroxycinnamates on late blight pathogenesis was evaluated. Mechanisms for increasing the resistance of potato plants to Phytophthora infestans were associated with the activation of the antioxidant system of plants and an increase in the level of gene transcripts that encode PR proteins: basic protective protein (PR-1), thaumatin-like protein (PR-5), protease inhibitor (PR-6), and peroxidase (PR-9). The revealed activation of the expression of marker genes of systemic acquired resistance and induced systemic resistance under the influence of the combined treatment of plants with B. subtilis and conjugates of chitin with hydroxycinnamates indicates that, in this case, the development of protective reactions in potato plants to late blight proceeds synergistically, where B. subtilis primes protective genes, and chitosan composites act as a trigger for their expression. [ABSTRACT FROM AUTHOR]