Sigatoka Leaf Spot Disease Research Articles

Identification of Sigatoka Leaf Spot Disease in Banana Using Convolutional Neural Network (CNN)

Aim: Rapid and Early identification of the cause of the disease enables prompt selection of the protection method and reduces the yield loss. Lag in disease diagnosis reduces the crop output and increases the cost of cultivation. To overcome this problem, deep learning techniques are used to identify Sigatoka leaf spot disease in bananas through image detection. CNN is a dependable method to identify the disease at the initial stages to help farmers.
 Place and Duration of the Study: Agricultural College and Research Institute, Tamil Nadu agricultural university, Coimbatore. Duration of the experiment was three months.
 Methodology: Image of diseased leaves and healthy leaves were collected from the different areas of Pollachi and Coimbatore, Tamil Nadu, India. Variations in colors were removed and the quality of the image was enhanced to increase the accuracy. The image dataset comprised of a total of 2008 images of banana Sigatoka leaf spot and healthy banana leaves for differentiation and evaluation. Initial stage of training includes loading of the image data for training, determining the learning rate, running the optimizer, and compiling the training convolution model. The model's accuracy is assessed in the last step, saving the accuracy and loss occurred during training.
 Results: The experiment result shows that disease detection accuracy of the intended model is 96.41%. It gives higher accuracy and improved performance.

Evaluation of different management practices against yellow Sigatoka disease of banana (Musa spp.) caused by Mycosphaerella musicola Leach

Leaf spot or yellow sigatoka disease (caused by Mycosphaerella musicola) of banana causes significant yield loss as well as in quality of fruits in every year and reported up to 65% or even more under favorable epidemic conditions. In this perspective, an experiment was conducted at ZBNF project Research field, college of horticulture, Sirsi (Uttara Kannada district of Karnataka) for consecutive two seasons (2020-21 & 2021-22). Experiment accompanied with RBD statistical design with five replications and four treatments. Four different management practices involving viz. Propiconazole 25EC @ 0.1% (Recommended package of practices-UHS, Bagalkot), Trichoderma harzianum 10g/lit. (Organic farming), sour butter milk 5 lit. per 200 liter of water (Natural farming) and Tebuconazole 50% + Trifloxystrobin 25% WG @0.5gm/lit. (Chemical farming) were evaluated against sigatoka leaf spot disease. Among the management practices, chemical farming comprises tebuconazole 50%+ trifloxystrobin 25%WG@1gm/lit was found effective in managing the disease (12.38% PDI) followed by recommended package of practice comprises propiconazole 25%EC @1ml/l (16.33% PDI), organic farming comprises of talk-based Trichoderma harzianum 10g/lit (17.33% PDI). Natural farming showed least effective to combat disease recorded maximum disease severity (19.66% PDI) after 210 days after planting. Although chemical farming can effectively control the disease but results in the serious risk on human health and environmental hazards. Therefore, organic and natural farming are an alternative approach that are eco-friendly and economically viable against sigatoka leaf spot disease management.

A smart agriculturing IoT system for banana plants disease detection through inbuilt compressed sensing devices

The Internet of Things (IoT) solutions for agriculture are rapidly growing and have the potential to transform agriculture in many aspects. In particular, the plant disease detection devices play a vital role in improving the agriculture. The visual monitoring of plants for the onset of diseases is a tedious and time-consuming task for farmers and at the same time it is less accurate. Hence an automated system with environmental data and camera sensors can serve as an alternative and effective solution for manual monitoring of plants. In this paper, a novel and efficient compressed sensing inbuilt plant disease detection device is developed which uses a foreground-based segmentation method and two step feature extraction technique to detect and classify two of the major banana diseases. A database is created for banana bunchy top and sigatoka leaf spot diseases by collecting images in real time from the fields of southern parts of Tamilnadu namely Thadiyankudisai and Thandikudi of Dindigul district, KC Patti, Muthalapuram, Suruli Patti and Kambam of Theni district and ICAR NRCB, Tiruchirapalli. The performance of the proposed device has been evaluated in terms of percentage of the infected areas, the detection accuracy, the percentage of reduction in features and the classification accuracy. The prototype of the proposed device is developed and validated using the Raspberry pi board. The results show that the proposed device achieves detection accuracy of 96.75% and classification accuracy of 97.33%.

Characterization of microRNAs and Target Genes in Musa acuminata subsp. burmannicoides, var. Calcutta 4 during Interaction with Pseudocercospora musae

Endogenous microRNAs (miRNAs) are small non-coding RNAs that perform post-transcriptional regulatory roles across diverse cellular processes, including defence responses to biotic stresses. Pseudocercospora musae, the causal agent of Sigatoka leaf spot disease in banana (Musa spp.), is an important fungal pathogen of the plant. Illumina HiSeq 2500 sequencing of small RNA libraries derived from leaf material in Musa acuminata subsp. burmannicoides, var. Calcutta 4 (resistant) after inoculation with fungal conidiospores and equivalent non-inoculated controls revealed 202 conserved miRNAs from 30 miR-families together with 24 predicted novel miRNAs. Conserved members included those from families miRNA156, miRNA166, miRNA171, miRNA396, miRNA167, miRNA172, miRNA160, miRNA164, miRNA168, miRNA159, miRNA169, miRNA393, miRNA535, miRNA482, miRNA2118, and miRNA397, all known to be involved in plant immune responses. Gene ontology (GO) analysis of gene targets indicated molecular activity terms related to defence responses that included nucleotide binding, oxidoreductase activity, and protein kinase activity. Biological process terms associated with defence included response to hormone and response to oxidative stress. DNA binding and transcription factor activity also indicated the involvement of miRNA target genes in the regulation of gene expression during defence responses. sRNA-seq expression data for miRNAs and RNAseq data for target genes were validated using stem-loop quantitative real-time PCR (qRT-PCR). For the 11 conserved miRNAs selected based on family abundance and known involvement in plant defence responses, the data revealed a frequent negative correlation of expression between miRNAs and target host genes. This examination provides novel information on miRNA-mediated host defence responses, applicable in genetic engineering for the control of Sigatoka leaf spot disease.

Transcriptome Profiling of the Resistance Response of Musa acuminata subsp. burmannicoides, var. Calcutta 4 to Pseudocercospora musae.

Banana (Musa spp.), which is one of the world's most popular and most traded fruits, is highly susceptible to pests and diseases. Pseudocercospora musae, responsible for Sigatoka leaf spot disease, is a principal fungal pathogen of Musa spp., resulting in serious economic damage to cultivars in the Cavendish subgroup. The aim of this study was to characterize genetic components of the early immune response to P. musae in Musa acuminata subsp. burmannicoides, var. Calcutta 4, a resistant wild diploid. Leaf RNA samples were extracted from Calcutta 4 three days after inoculation with fungal conidiospores, with paired-end sequencing conducted in inoculated and non-inoculated controls using lllumina HiSeq 4000 technology. Following mapping to the reference M. acuminata ssp. malaccensis var. Pahang genome, differentially expressed genes (DEGs) were identified and expression representation analyzed on the basis of gene ontology enrichment, Kyoto Encyclopedia of Genes and Genomes orthology and MapMan pathway analysis. Sequence data mapped to 29,757 gene transcript models in the reference Musa genome. A total of 1073 DEGs were identified in pathogen-inoculated cDNA libraries, in comparison to non-inoculated controls, with 32% overexpressed. GO enrichment analysis revealed common assignment to terms that included chitin binding, chitinase activity, pattern binding, oxidoreductase activity and transcription factor (TF) activity. Allocation to KEGG pathways revealed DEGs associated with environmental information processing, signaling, biosynthesis of secondary metabolites, and metabolism of terpenoids and polyketides. With 144 up-regulated DEGs potentially involved in biotic stress response pathways, including genes involved in cell wall reinforcement, PTI responses, TF regulation, phytohormone signaling and secondary metabolism, data demonstrated diverse early-stage defense responses to P. musae. With increased understanding of the defense responses occurring during the incompatible interaction in resistant Calcutta 4, these data are appropriate for the development of effective disease management approaches based on genetic improvement through introgression of candidate genes in superior cultivars.

Symptomatology of Sigatoka leaf spot disease in banana landraces and identification of its pathogen as Mycosphaerella eumusae

Mycosphaerella musicola, M. fijiensis and M. eumusae are known to cause banana yellow Sigatoka, black Sigatoka and Eumusae leaf spot diseases respectively. However, differentiating the causative species has been challenging and the responses of banana landraces to this pathogen were little known. Purposive sampling surveys were conducted in different agro-climatic zones of Kerala state, India, to collect the leaf samples with Sigatoka leaf spot-like symptoms, to document the symptom expression on different landraces and to confirm the identity of the pathogen at species level. Fields surveyed during the post-monsoon period had 100% disease incidence with highest per cent disease severity of 43.90% in nine-month old cv. Palayankodan, while lowest PDS of 3.33% was observed in three-month old cv. Njalipoovan, during a pre-monsoon survey. Initial symptoms were small brown streaks, later developing into oval or elliptical brown spots with greyish centre and subsequently coalescing for leaf necrosis. Symptoms in different landraces varied across the zones. Sequencing and analysis of the ITS region from 50 isolates collected during the survey showed 99–100% homology with M. eumusae . Phylogenetic analyses further proved the species identity of the local isolates. Comparing the ITS barcodes of the three species of Mycosphaerella along with the local isolates confirmed that the pathogen inciting Sigatoka leaf spot in Kerala state, India, is Mycosphaerella eumusae .

Management of sigatoka leaf spot disease of banana with fungicides and petroleum based mineral oil formulations

The experiment was carried out at Horticultural Research Station, O.U.A.T, Bhubaneswar during 2013–14 and 2014–15 with the objectives of finding out the best treatment for management of sigatoka leaf spot disease (Mycosphaerella musicola) of banana. The investigation revealed that among eight treatments tested, T6 (application of 0.05 per cent propiconazole + 1 per cent mineral oil) recorded its superiority in respect of disease control, yield and quality of fruit than rest of the treatments. This treatment also resulted in least disease severity and more disease free leaves (YLS) (1.29 & 7.7 respectively) along with the highest bunch yield (21.00 kg plant−1) and B:C ratio of 2.60. Difenconazole 1 ml l−1 (0.1%)+ petroleum based mineral oil (1%) with the disease severity of 1.89 in 0–6 scale was found to be the second best treatment. Maximum disease severity and lowest bunch weight was observed in control. Hence, the spraying(s) of 0.05 per cent propiconazole + 1 per cent mineral oil is recommended for effective control of sigatoka leaf spot disease of banana.

Bio-efficacy and phytotoxicity study of pyraclostrobin 133g/l + epoxyconazole 50 g/l SE(Opera 18.3% SE) against Sigatoka leaf spot disease of banana caused by Mycosphaerella musicola

Two to three sprays of pyraclostrobin 13.3% + epoxyconazole 5%(Opera 18.3%)@0.15% effectively controlled the Sigatoka leaf spot disease but this treatment was as par with propiconazole 0.1 per cent. The next best treatments were pyraclostrobin 13.3% + epoxyconazole 5% (Opera 18.3%)@0.125% and epoxyconazole 7.5%EC.With regard to yield, the treatment propiconazole @ 0.1 % recorded the highest yield of 31.94 t/ha followed by pyraclostrobin 13.3% + epoxyconazole 5%@0.15% (29.95 t/ha) and it was lowest in control. Phytotoxicity symptoms like chlorosis, necrosis, wilting, scorching, hyponasty and epinasty were not noticed in any of the treatments.

Performance of triploid cultivars of banana (<italic>Musa spp</italic>.) under Maharashtra conditions

The present study was undertaken to evaluate ten cultivars of banana (Musa sp.) belonging to different genomic groups (AAA, AAB and ABB) for growth, yield and quality attributes as well as its reaction to Sigatoka leaf spot disease. From the evaluation of the data for growth, yield and quality parameters, it was evident that cv.Grand naine has recorded better horticultural performance than other cultivars studied. It was also inferred that all the cultivars from AAA genomic group recorded B: C ratio in the range of 1.65to 2.29, while rest of the cultivars from AAB and ABB genomic group recorded B:C ratio in between 0.76 to 1.08. The cv. Grand naine was found better in respect of growth, duration, yield and quality attributes with good market potential under Maharashtra conditions.

Evaluation of banana germplasm against sigatoka leaf spot disease under natural conditions

Evaluation of banana germplasm against sigatoka leaf spot disease under natural conditions

Management of sigatoka leaf spot disease with oil based formulation

The experiment was carried out at The Banana Research Station, Jalgaon during 2010 to 2013 with an object to find out the best treatment for control of Sigatoka leaf spot disease of banana ( Mycosphaerella musicola ). The results of present investigation revealed that the treatment of 0.05 per cent propiconazole + 1 per cent mineral oil recorded its superiority in respect of disease control yield and quality of fruit than rest of the treatments studied. The least disease incidence and intensity (13.16%) The highest yield(22.18 kg/plant)along with B:C ratio of 2.22 was recorded by treatment of spraying 0.05 per cent propiconazole along with oil based formulation i.e. 1 per cent mineral oil than control. Hence the spraying /s of 0.05 per cent propiconazole + 1 per cent mineral oil is recommended for effective control of sigatoka leaf spot disease of banana.

Evaluation of banana hybrids for tolerance to black leaf streak (Mycosphaerella fijiensis Morelet) in Puerto Rico

In Puerto Rico, bananas (including plantains) are important agricultural commodities; their combined production totaled over 158,000 tons in 2011. Black leaf streak (BLS) and Sigatoka leaf spot diseases, caused by Mycosphaerella fijiensis and Mycosphaerella musicola, respectively, are responsible for significant losses of this crop, due to the high susceptibility of the most important cultivars. Diploid, triploid and tetraploid hybrids were introduced from international breeding programs for evaluation in Isabela, Puerto Rico. Accessions were established in the field in a randomized complete block design and were evaluated over two cropping cycles (2007–2010) for response to BLS and agronomic traits. Significant differences (P = 0.05) in BLS severity were observed among accessions throughout both crop cycles and were most pronounced at harvest. When averaged across production cycles, severity indices at harvest ranged from very resistant (20% of the leaf surface affected) for ‘FHIA 02’ to extremely susceptible (97%) for ‘Grand Nain’. Yield attributes varied widely among the accessions, including mean bunch weights (6.9–41.0 kg), numbers of hands per bunch (6.6–13.4), and the numbers of fruit per bunch (57.0–239.2). Several accessions, mainly from the Fundación Hondureña de Investigación Agrícola (FHIA), were BLS resistant and had short pseudostems, and large bunches. They could potentially replace susceptible cultivars in commercial production or play roles in a nascent organic market.

Persistence of trifloxystrobin and tebuconazole in banana tissues and soil under the semi-arid climatic conditions of Karnataka, India

Trifloxystrobin and tebuconazole are used for control of Sigatoka leaf spot disease of banana. This study was conducted to evaluate residue persistence of the fungicides in/on banana fruit, other edible parts and soil after spray application of the combination formulation, Nativo 75 WG, at the standard dose, 87.5 + 175 and double dose, 175 + 350 g a.i. ha−1. The fungicides were extracted from banana and soil with acetone, partitioned into dichloromethane and cleaned-up using activated charcoal for trifloxystrobin and primary/secondary amine (PSA) for tebuconazole samples. The limit of quantification of the method was 0.05 mg kg−1 for both fungicides. Initial residues of trifloxystrobin were 0.444 and 0.552 mg kg−1 in/on banana with peel (whole fruit), which reached <0.05 and 0.065 mg kg−1 after 30 days from treatment at the standard and double doses, respectively. Tebuconazole residues were 0.636 and 960 mg kg−1 initially and reduced to 0.066 and 0.101 mg kg−1 after 30 days. Trifloxystrobin and tebuconazole degraded with the half-life of about 11 days. Trifloxystrobin or its metabolite was not detected in the fruit pulp. Tebuconazole being systemic in nature moved to the fruit pulp which was highest on the 3rd day (0.103 and 0.147 mg kg−1) and remained for 15 days. Matured banana fruit, flower, pseudostem and field soil were free from fungicide residues. For consumption of raw banana 43 days pre-harvest interval (PHI) is required after treatment of the combination formulation. Therefore application of the fungicides towards maturity stage of the fruits may be avoided.

NECROTIC LEAF REMOVAL: AN EFFECTIVE METHOD TO LIMIT THE GREEN LIFE SHORTENING EFFECTS OF SIGATOKA LEAF SPOT DISEASE IN BANANAS

ISHS VII International Symposium on Banana: ISHS-ProMusa Symposium on Bananas and Plantains: Towards Sustainable Global Production and Improved Use NECROTIC LEAF REMOVAL: AN EFFECTIVE METHOD TO LIMIT THE GREEN LIFE SHORTENING EFFECTS OF SIGATOKA LEAF SPOT DISEASE IN BANANAS

Analysis of the leaf transcriptome of Musa acuminata during interaction with Mycosphaerella musicola: gene assembly, annotation and marker development.

BackgroundAlthough banana (Musa sp.) is an important edible crop, contributing towards poverty alleviation and food security, limited transcriptome datasets are available for use in accelerated molecular-based breeding in this genus. 454 GS-FLX Titanium technology was employed to determine the sequence of gene transcripts in genotypes of Musa acuminata ssp. burmannicoides Calcutta 4 and M. acuminata subgroup Cavendish cv. Grande Naine, contrasting in resistance to the fungal pathogen Mycosphaerella musicola, causal organism of Sigatoka leaf spot disease. To enrich for transcripts under biotic stress responses, full length-enriched cDNA libraries were prepared from whole plant leaf materials, both uninfected and artificially challenged with pathogen conidiospores.ResultsThe study generated 846,762 high quality sequence reads, with an average length of 334 bp and totalling 283 Mbp. De novo assembly generated 36,384 and 35,269 unigene sequences for M. acuminata Calcutta 4 and Cavendish Grande Naine, respectively. A total of 64.4% of the unigenes were annotated through Basic Local Alignment Search Tool (BLAST) similarity analyses against public databases.Assembled sequences were functionally mapped to Gene Ontology (GO) terms, with unigene functions covering a diverse range of molecular functions, biological processes and cellular components. Genes from a number of defense-related pathways were observed in transcripts from each cDNA library. Over 99% of contig unigenes mapped to exon regions in the reference M. acuminata DH Pahang whole genome sequence. A total of 4068 genic-SSR loci were identified in Calcutta 4 and 4095 in Cavendish Grande Naine. A subset of 95 potential defense-related gene-derived simple sequence repeat (SSR) loci were validated for specific amplification and polymorphism across M. acuminata accessions. Fourteen loci were polymorphic, with alleles per polymorphic locus ranging from 3 to 8 and polymorphism information content ranging from 0.34 to 0.82.ConclusionsA large set of unigenes were characterized in this study for both M. acuminata Calcutta 4 and Cavendish Grande Naine, increasing the number of public domain Musa ESTs. This transcriptome is an invaluable resource for furthering our understanding of biological processes elicited during biotic stresses in Musa. Gene-based markers will facilitate molecular breeding strategies, forming the basis of genetic linkage mapping and analysis of quantitative trait loci.

Improved tolerance toward fungal diseases in transgenic Cavendish banana (Musa spp. AAA group) cv. Grand Nain

The most devastating disease currently threatening to destroy the banana industry worldwide is undoubtedly Sigatoka Leaf spot disease caused by Mycosphaerella fijiensis. In this study, we developed a transformation system for banana and expressed the endochitinase gene ThEn-42 from Trichoderma harzianum together with the grape stilbene synthase (StSy) gene in transgenic banana plants under the control of the 35S promoter and the inducible PR-10 promoter, respectively. The superoxide dismutase gene Cu,Zn-SOD from tomato, under control of the ubiquitin promoter, was added to this cassette to improve scavenging of free radicals generated during fungal attack. A 4-year field trial demonstrated several transgenic banana lines with improved tolerance to Sigatoka. As the genes conferring Sigatoka tolerance may have a wide range of anti-fungal activities we also inoculated the regenerated banana plants with Botrytis cinerea. The best transgenic lines exhibiting Sigatoka tolerance were also found to have tolerance to B. cinerea in laboratory assays.

Artificial inoculation on plants and banana leaf pieces withMycosphaerellaspp., responsible for Sigatoka leaf spot diseases

Ce protocole vise (i) a analyser la nature des interactions hotes-parasites (resistance ou sensibilite), (ii) a etudier la variabilite de la pathogenicite de differentes populations pathogenes (intra/interspecifiques) quant a leur virulence et leur agressivite mesurees a partir d''inoculation artificielle avec Mycosphaerella fijiensis ou Mycosphaerella musicola sur des plants et des morceaux de feuille de bananier. Le principe, les principaux avantages, le materiel vegetal de depart et le temps necessaire de la methode sont presentes. Materiel et methodes. Le materiel de laboratoire necessaire et le detail des seize etapes de realisation du protocole (preparation de l'inoculum conidial, inoculation artificielle sur des plants de bananier, et inoculation artificielle sur des morceaux de feuille de bananier) sont decrits. Des problemes potentiels sont evoques. Resultats. Des symptomes-types de la maladie sont obtenus apres inoculation artificielle (Resume d'auteur)

Pest risk assessment made by France on Mycosphaerella fijiensis considered by France as harmful in French overseas departments of French Guiana, Guadeloupe, Martinique and Réunion ‐ Scientific Opinion of the Panel on Plant Health

SUMMARY Following a request from the European Commission, the Panel on Plant Health was asked to deliver a scientific opinion on 30 pest risk assessments made by France on organisms which are considered by France as harmful in four French overseas departments, i.e. French Guiana, Guadeloupe, Martinique and Reunion. In particular, the Panel was asked whether these organisms can be considered as harmful organisms for the endangered area of the above departments, in the meaning of the definition mentioned in Article 2.1.(e) of Directive 2000/29/EC and thus potentially eligible for addition to the list of harmful organisms in Directive 2000/29/EC. This document presents the opinion of the Panel on Plant Health on the full 2 pest risk assessment conducted by France on Mycosphaerella fijiensis with French Guiana, Guadeloupe, Martinique and Reunion considered as endangered area. Three related fungal species within the genus Mycosphaerella induce important leaf spot diseases on Musa spp.: M. fijiensis, M. musicola and M. eumusae. They cause black leaf streak disease, Sigatoka leaf spot disease and eumusae leaf spot disease, respectively. M. fijiensis and M. musicola are known to cause serious economic damage on banana. M. fijiensis is present in most Musa growing regions of the world, but it is absent from the PRA area.

Construction and characterization of a bacterial artificial chromosome library of the causal agent of Black Sigatoka fungal leaf spot disease of banana and plantain, Mycosphaerella fijiensis

A bacterial artificial chromosome library of the causal agent of the Black Sigatoka leaf spot disease of banana and plantain, Mycosphaerella fijiensis, has been constructed using a non-sphaeroplasting technique and characterized using both homologous and heterologous probes. After first and a second size selection of PFGE-fractionated DNA, a ligation was obtained using a 1:4 molar ratio (insert:vector). One hundred random clones were analyzed, and the mean insert size was estimated to be 90 kb. The range of the insert sizes was between 40 and 160 kb. The highest percentage of inserts belonged to the range between 80 and 100 kb; 32% of the inserts had 2 or 3 internal NotI sites. This library consists of 1920 clones, if the genomic size is at least 35 Mb, then this represents 4.9 x genome equivalents, which was supported by hybridization results with homologous and heterologous probes.

Black Sigatoka disease: new technologies to strengthen eradication strategies in Australia

In 2001, an incursion of Mycosphaerella fijiensis, the causal agent of black Sigatoka, was detected in Australia’s largest commercial banana growing region, the Tully Banana Production Area in North Queensland. An intensive surveillance and eradication campaign was undertaken which resulted in the reinstatement of the disease-free status for black Sigatoka in 2005. This was the first time black Sigatoka had ever been eradicated from commercial plantations. The success of the eradication campaign was testament to good working relationships between scientists, growers, crop monitors, quarantine regulatory bodies and industry. A key contributing factor to the success was the deployment of a PCR-based molecular diagnostic assay, developed by the Cooperative Research Centre for Tropical Plant Protection (CRCTPP). This assay complemented morphological identification and allowed high throughput diagnosis of samples facilitating rapid decision-making during the eradication campaign. This paper describes the development and successful deployment of molecular diagnostics for black Sigatoka. Shortcomings in the gel-based assay are discussed and the advantages of highly specific real-time PCR assays, capable of differentiating between Mycosphaerella fijiensis, Mycosphaerella musicola and Mycosphaerella eumusae are outlined. Real-time assays may provide a powerful diagnostic tool for applications in surveillance, disease forecasting and resistance testing for Sigatoka leaf spot diseases. Australasian Plant Pathology Society 2006