Diseases Of Banana Research Articles

Novel Studies on the Prevalence of Leaf Spot Disease of Banana and its Chemical Control in Lower Sindh, Pakistan

In the current study, different chemical fungicides were used for effective management of Fusarium oxysporum, which is a causal agent of banana leaf spot disease. A survey of the banana-infected field was conducted in various regions of Sindh, Pakistan; Recorded disease incidence showed that Thatta was severely affected by leaf spot up to (46.66%), followed by Badin (28.88%) and minimum disease incidence was recorded in Hyderabad (24.44%). The pre-dominant pathogen was morphologically identified as Fusarium oxysporum; for confirmation of casual fungal, a pathogenicity test was done by two different methods i.e root dipping and drenching method. It was observed that the root dipping method of inoculation showed higher leaf spots (06) development on banana as compared to drenching method; leaf spot (03) of inoculation. To determine the efficacy of various chemical fungicides, such as Melodyduo, Aliette, Prevail, Topsin-M and Ridomil gold, were used at different doses, such as 100, 200, and 300 ppm, the findings of the study indicates that F. oxysporum was completely stopped to grew against the Prevail and Topsin-M (0.00 mm) at 100, 200 and 300 ppm, respectively, while the vegetative growth of the targeted fungi was slightly high against Ridomil Gold (18.16, 15.66 and 5.75 mm), as well Melody duo (24.33, 19.08 and 13.75 mm). Maximum mycelial growth of the pathogen was observed under Aliette (32.00, 27.83 and 26.08 mm). The Fusarium oxysporum vigorously developed under control (90mm). Present findings of the study suggested that Prevail and Topsin-M considerably retarded the mycelial growth and positively controlled the targeted pathogen.

Characterization of O-methyltransferases in the biosynthesis of phenylphenalenone phytoalexins based on the telomere-to-telomere gapless genome of Musella lasiocarpa.

Phenylphenalenones (PhPNs), phytoalexins in wild bananas (Musaceae), are known to act against various pathogens. However, the abundance of PhPNs in many Musaceae plants of economic importance is low. Knowledge of the biosynthesis of PhPNs and the application of biosynthetic approaches to improve their yield is vital for fighting banana diseases. However, the processes of PhPN biosynthesis, especially those involved in methylation modification, remain unclear. Musella lasiocarpa is a herbaceous plant belonging to Musaceae, and due to the abundant PhPNs, their biosynthesis in M. lasiocarpa has been the subject of much attention. In this study, we assembled a telomere-to-telomere gapless genome of M. lasiocarpa as the reference, and further integrated transcriptomic and metabolomic data to mine the candidate genes involved in PhPN biosynthesis. To elucidate the diversity of PhPNs in M. lasiocarpa, three screened O-methyltransferases (Ml01G0494, Ml04G2958, and Ml08G0855) by phylogenetic and expressional clues were subjected to in vitro enzymatic assays. The results show that the three were all novel O-methyltransferases involved in the biosynthesis of PhPN phytoalexins, among which Ml08G0855 was proved to function as a multifunctional enzyme targeting multiple hydroxyl groups in PhPN structure. Moreover, we tested the antifungal activity of PhPNs against Fusarium oxysporum and found that the methylated modification of PhPNs enhanced their antifungal activity. These findings provide valuable genetic resources in banana breeding and lay a foundation for improving disease resistance through molecular breeding.

Molecular insights into the variability and pathogenicity of Fusarium odoratissimum, the causal agent of Panama wilt disease in banana

Fusarium wilt or Panama disease of banana caused by the hemibiotroph fungus, Fusarium odoratissimum, also known as F. oxysporum f.sp. cubense Tropical Race 4 is a serious threat to banana production worldwide. Being the world's largest grower and the origins of bananas in its northeast region, India is particularly vulnerable to this deadly fungus. In the present study, a total of 163 Fusarium isolates from infected banana were characterized for their pathogenic traits. Considering the variability in the Fusarium, the contaminated banana plants were collected from five districts of Uttar Pradesh and Bihar, two major primary infection states of India. All the isolates were screened using universal and specific primers to identify the F. odoratissimum strains. The identified F. odoratissimum strains were subjected to in vivo pathogenicity assessment using the susceptible banana cultivar ‘Grand Naine’. The identified six most virulent strains were further characterized for their pathogenicity via in vivo bipartite interaction in terms of biochemical assays. Assessment of in vivo pathogenicity through qRT-PCR for three pathogenesis responsive genes, Six 1a (Secreted in xylem), Snf (Sucrose non-fermenting) and ChsV (Chitinase V), ascertained that the identified F. odoratissimum strains exhibit both intra- and inter-specific variability. The variability of F. odoratissimum strains signifies its importance for the assessment of spread of infection at specific sites to enable efficient management strategy of Fusarium wilt in banana.

First Report of Bulb Rot Disease of Banana Caused by Klebsiella variicola in China.

Banana (Musa spp.) is an economically important fruit and food crop globally as well as in China. In March 2023, a bulb rot disease was observed on more than 20% of cultivated dwarf bananas in a plantation in Wuming County of Guangxi Province, a major hub of banana production in China. Infected plants showed crackles at the basal part of stem and were relatively dwarf, while yellowing of the leaves was not observed. When the rhizomes were cut open, water-soaked lesions with a yellow or black margin can be seen in the bulb. In severe infections, the internal tissue became dry or wet rot, and there was typical dark-brown cavity formation in the bulb. The rot was limited to the bulb. To isolate the causal agent, dissected diseased tissues (5×5 mm) were surface sterilized with 75% ethanol (30 s) and 2% NaClO (3 min), followed by three rinses with sterile water. The sterilized sections were soaked in 2 mL of sterile water and shaken for 5 min in a vortex oscillator. The suspension was streaked on Luria-Bertani (LB) agar medium, and incubated at 28℃ for 24 h. Single colonies were re-streaked three times to obtain purified isolation. Twelve pure bacterial cultures with similar morphology were isolated from three plants taken from the field. The bacterial colonies were yellowish white, mucoid, round, and raised with translucent surfaces on the LB agar plate. Three strains Gxkv1, Gxkv2 and Gxkv3 were selected for further analyses. The 16S rDNA gene (GenBank Accession OR461756, PP094726 and PP109349) were amplified using primer pair 27F/1492R (Frank et al. 2008). Comparing 16S sequences against GenBank showed 99.86%-100% sequence identity to Klebsiella variicola strain (MZ475068) for the three isolates Gxkv1 (1,398/1,398 bp), Gxkv2 (1,398/1,396 bp) and Gxkv3 (1,398/1,398 bp). A multilocus phylogenetic analysis was conducted by neighbor-joining method (1,000 bootstrap values) based on three housekeeping gene sequences of gyrA (GenBank Accession No. OR515493, PP105747, PP105748), rpoB (OR515494, PP105751, PP105752 ) and infB (OR515495, PP105749, PP105750) genes which were amplified by gyrA-A/gyrA-C, CM31b/CM7 and infB867F/infB1819R primer sets, respectively (Rosenblueth et al. 2004). The results of phylogenetic analysis showed the three strains belong to the K. variicola clade. A pathogenicity test was conducted on six healthy 3-month-old dwarf banana plants by spraying 10 mL of bacterial suspensions of Gxkv1 (108 CFU/mL) into the rhizome which wounded with a sterilized needle; another six healthy control plants were sprayed with 10 mL of sterile water. Following inoculation, the plants were placed in a greenhouse at 28-32°C. After 30 days, all inoculated plants showed symptoms similar to those observed in the field, while the control plants remained healthy. Bacteria were successfully reisolated from the symptomatic tissues and identified to be K. variicola by PCR mentioned above. K. variicola has been reported to cause rhizome rot of banana in India (Loganathan et al. 2021), and to cause plantain soft rot in Haiti (Fulton et al. 2021). Besides, previous reports from China only showed K. variicola causing banana sheath rot (Fan et al. 2015, Sun et al. 2023). To our knowledge, this is the first report of bulb rot disease of banana caused by K. variicola in Guangxi Province, China. This finding will provide important information for studying the epidemiology and management of this pathogen.

Mobile-Based convolutional neural network model for the early identification of banana diseases

This study aimed to deploy a deep learning model in a mobile application for the early identification of Fusarium Wilt and Black Sigatoka in bananas. In this paper, a Convolutional Neural Network (CNN) model for the classification of Black Sigatoka banana disease and Fusarium Wilt disease is assessed. A dataset of 27,360 images of diseased and healthy banana leaves and stalks that were collected from the farms using a mobile phone camera served as the training data for this model. An extra class of 407 images that are not of the banana plant downloaded from the internet was used to help the model detect other images not of the banana plant. The CNN model achieved an accuracy of 91.17 % and was deployed in a mobile application for the classification of the diseases. This study shows that deep learning can be implemented and assist in the early identification of banana diseases. The application could detect images of healthy and diseased banana leaves and stalks and images not of the banana plant with a confidence score of more than 90 % in less than five seconds per image and provide research-based mitigation recommendations.

Rice straw increases microbial nitrogen fixation, bacterial and nifH genes abundance with the change of land use types.

Soil microorganisms play an important role in soil ecosystems as the main decomposers of carbon and nitrogen. They have an indispensable impact on soil health, and any alterations in the levels of organic carbon and inorganic nitrogen can significantly affect soil chemical properties and microbial community composition. Previous studies have focused on the effects of carbon and nitrogen addition on a single type of soil, but the response of soil microorganisms to varying carbon and nitrogen inputs under different land soil use types have been relatively understudied, leaving a gap in our understanding of the key influencing factors. To address this gap, we conducted a study in the tropical regions of Hainan province, focusing on four distinct land use types: natural forest soil (NS), healthy banana soil (HS), diseased banana garden soil (DS), and paddy soil (PS). Within each of these environments, we implemented five treatments: CK, RS (rice straw), RSN (rice straw and NH4NO3), RR (rice root), and RRN (rice root and NH4NO3). Our aim was to investigate how soil bacteria response to changes in carbon and nitrogen inputs, and to assess their potential for biological nitrogen fixation. The results showed that the addition of rice straw increased the absorption and utilization of nitrate nitrogen by microorganisms. The addition of rice roots (RR) did not increase the absorption capacity of inorganic nitrogen by microorganisms, but increased the content of poorly soluble organic carbon. Most importantly, the addition of rice straw increased microbial respiration and the utilization efficiency of N2 by microorganisms, and the further addition of ammonium nitrate increased microbial respiration intensity. With the change of soil type, the rice straw increases microbial nitrogen fixation, bacterial and nifH genes abundance. Meanwhile, microbial respiration intensity is an important factor influencing the differences in the structure of bacterial communities. The addition of inorganic nitrogen resulted in ammonium nitrogen accumulation, reduced microbial richness and diversity, consequently diminishing the soil microorganisms to resist the environment. Therefore, we believe that with the change of soil types, corresponding soil nutrient retention strategies should be devised and incorporated while reducing the application of ammonium nitrogen, thus ensuring healthy soil development.

First report of black leaf streak disease in bananas caused by Pseudocercospora fijiensis on Mauritius island.

Pseudocercospora fijiensis, the causal agent of the black leaf streak disease of bananas (plants in the genus Musa) (BLSD), is considered to be the major economic threat to export-banana cultivation (de Bellaire, Fouré, Abadie, & Carlier, 2010). The disease has a worldwide distribution throughout the humid tropical regions and has been previously reported in the Southwestndian Ocean (SWIO) area: in 1993 in Mayotte and Comoros islands (DR Jones & Mourichon, 1993), in 2000 in Madagascar (Jones, 2003; Rivas, Zapater, Abadie, & Carlier, 2004) and in 2018 in Reunion Island (Rieux et al., 2019). In Mauritius, the presence of Pseudocercospora fijiensis was suspected in 1996 (Soomary & Benimadhu, 1998) but has never been confirmed, as symptoms could have been confounded with Pseudocercospora musae or Pseudocercospora eumusae, two causal agents of others leaf spot diseases of banana which were previously described in Mauritius in 1959 (Orieux & Felix, 1968) and 2000 (Carlier, Zapater, Lapeyre, Jones, & Mourichon, 2000), respectively. In March 2022, typical BLSD symptoms were observed at relatively low prevalence in a Cavendish crop located in the "Balance John" area (site S1 on Fig. S1-A) of Mauritius island. Typical early symptoms (stages 2) were 1- to 4-mm long brown streaks at the abaxial leaf surface, and typical older streaks (stages 3 and 4) were also observed (Fig. S1-B). These symptoms were mixed with symptoms of ELSD caused by P. eumusae. Since both species cannot be clearly distinguished only on the description of symptoms, conidial sporulation on stages 2 was checked in the laboratory (Ngando et al., 2015) since P. eumusae does not produce conidia on these young stages. In April 2022, banana leaves bearing symptoms of leaf spot diseases were collected in 7 different sites (Fig. S1-A). All leaf fragments were sent to the CIRAD laboratories where molecular diagnosis was performed following the protocol developed by Arzanlou et al. (2007). In brief, genomic DNA was extracted from ground leaf fragments displaying symptoms using the DNeasy® Plant Mini Kit (Qiagen®, Courtaboeuf, France). At each site, a total of 6 lesions cut from 6 different leaves were pooled. The DNA extracts were added as templates for real-time PCR assay designed to specifically detect the presence of P. fijiensis, P. musae and P. eumusae using MFbf/MFbrtaq/MFbp, MEbf/MEbrtaq/FMep and MMbf/Mmbrtaq/FMep primers and probes, respectively (Arzanlou et al., 2007). Both positive and negative controls were included in the assay and every sample reaction was duplicated. P. fijiensis was detected from 2 out of 7 sites (S2 and S7, see Fig.S2-B). P. eumusae was detected at all sites while P. musae was found in one site only (S6). Interestingly, our results also showed coinfection by P. fijiensis - P. eumusae & P. musae - P. eumusae on several sites. The presence of P. fijiensis was further confirmed by several investigations performed on conidia isolated from S2 samples including i) morphological observations of conidia displaying P. fijiensis type description (Pérez-Vicente, Carreel, Roussel, Carlier, & Abadie (2021), Fig. S2-A), ii) DNA sequencing of 16S ribosomal gene with ITS1 & ITS4 primers (GenBank accessions Nos. OR515818-OR515810) with BLAST results displaying percentages of identity > 99.70% with type strains and iii) Koch's postulates were fulfilled by artificial inoculation of detached leaf pieces as described in Pérez-Vicente, Carreel, Roussel, Carlier, & Abadie (2021) (Fig. S2-D). In brief, for the artificial inoculation, symptoms obtained after inoculation of both a strain isolated in Mauritius (S2-MAU) and a positive control (T+) were compared and shown to be typical of P. fijiensis species for the 3 replicates. To the best of our knowledge, this is the first official report of P. fijiensis and BLSD in Mauritius Island. This revelation holds significant importance for both the agricultural and scientific communities, shedding light on the potential spread and impact of this devastating pathogen in previously unaffected regions. From a global perspective, this discovery underscores the interconnectedness of agricultural ecosystems and the need for vigilance in monitoring and responding to emerging plant diseases in an increasingly interconnected world (Vega et al. 2022). Future investigations will be required to monitor the spread of BLSD on the island, describe the genetic structure of populations and identify routes of invasion at the SWOI scale.

Growth Enhancement and Resistance of Banana Plants to Fusarium Wilt Disease as Affected by Silicate Compounds and Application Frequency.

The amendment of soils with silicate (Si) compounds is essential to promote growth performance and control Fusarium wilt disease in bananas. Two successive greenhouse trials were conducted at the experimental farm of the University of Putra Malaysia. The treatments were arranged in split plots using a randomized complete block design (RCBD) with four replicates to investigate the effects of Si compounds and application frequency on controlling FOC. Si compounds were used at a constant concentration of 0.1%: T0 (control), T1 (13% SiO2:20% K2O), T2 (26.6% SiO2:13.4% K2O) and T3 (36.2% SiO2:17% Na2O). There were three application frequencies by day intervals (DI): 0DI (without any application), 7DI (12× within 12 weeks after transplanting (WAT)), 15DI (6× within 12 WAT) and 30DI (3× within 12 WAT). From these findings, we observed that the photosynthesis rate started to increase from 10.6 to 19.4 µmol CO2 m-2s-1, when the total chlorophyll content started to increase from 3.85 to 7.61 mgcm-2. The transpiration rate started to increase from a value of 1.94 to 4.31 mmol H2O m-2s-1, when the stomata conductance started to increase from 0.237 to 0.958 mmol m-2s-1. The proline content started to increase from 22.89 to 55.07 µmg-1, when the relative water content started to increase from 42.92 to 83.57%.

Preference of Pentalonia nigronervosa for infected banana plants tends to reverse after Banana bunchy top virus acquisition

Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) is the vector of the Banana Bunchy Top Virus (BBTV), the most serious viral disease of banana (Musa spp.) in the world. Before acquiring the virus, the vector is more attracted to infected banana plants in response to the increased emissions of volatile organic compounds (VOCs). Here, we test the hypothesis that BBTV acquisition directly modifies the preference of P. nigronervosa for infected banana plants, and that the change in preference results from the alteration of the organs linked to the VOC detection or to the behaviour of the vector. We found that the preference of P. nigronervosa for infected banana plants reverses after virus acquisition in dessert banana, while it remains similar between healthy and infected banana plants before and after the acquisition of BBTV. At the same time, aphids reared on infected bananas had smaller forewing areas and hind tibia length than aphids reared on healthy bananas, although the number of secondary rhinaria on the antennae was lower on dessert banana-reared aphids than plantain-reared aphids, this was not affected by the infection status of the aphid. These results support the "vector manipulation hypothesis—VMH" of pathogens to promote their spread. They have implications for the BBTV management.

Identification of banana ADA1 gene family members and their expression profiles under biotic and abiotic stresses

The Spt-Ada-Gcn5-acetyltransferase (SAGA) is an ancillary transcription initiation complex which is highly conserved. The ADA1 (alteration/deficiency in activation 1, also called histone H2A functional interactor 1, HFI1) is a subunit in the core module of the SAGA protein complex. ADA1 plays an important role in plant growth and development as well as stress resistance. In this paper, we performed genome-wide identification of banana ADA1 gene family members based on banana genomic data, and analyzed the basic physicochemical properties, evolutionary relationships, selection pressure, promoter cis-acting elements, and its expression profiles under biotic and abiotic stresses. The results showed that there were 10, 6, and 7 family members in Musa acuminata, Musa balbisiana and Musa itinerans. The members were all unstable and hydrophilic proteins, and only contained the conservative SAGA-Tad1 domain. Both MaADA1 and MbADA1 have interactive relationship with Sgf11 (SAGA-associated factor 11) of core module in SAGA. Phylogenetic analysis revealed that banana ADA1 gene family members could be divided into 3 classes. The evolution of ADA1 gene family members was mostly influenced by purifying selection. There were large differences among the gene structure of banana ADA1 gene family members. ADA1 gene family members contained plenty of hormonal elements. MaADA1-1 may play a prominent role in the resistance of banana to cold stress, while MaADA1 may respond to the Panama disease of banana. In conclusion, this study suggested ADA1 gene family members are highly conserved in banana, and may respond to biotic and abiotic stress.

Efficacy of Novel Fungicides against the Fusarium oxysporum f.sp. cubense Causing Panama wilt of Banana

Panama wilt of banana caused by Fusarium oxysporum f.sp. cubense TR4 is considered as most devastating disease of bananas. In Bihar, this disease became a menace to banana growers of Bihar due to introduction of new highly virulent strains i.e.TR 4 strain B2. The objectives of this study were to evaluate newly available fungicides under in vitro and in vivo conditions for the efficient management of the Panama wilt of banana. Fourteen different fungicides and novel chemicals were tested in vitro as well as in vivo conditions. Native (tebuconazole 50% + trifloxystrobin 25%) was found to exhibit 100% inhibition over control in vitro whereas in pot conditions 86.2% inhibition over control was observed against Fusarium oxysporum f.sp. cubense TR 4 strain B2 in cultivar Alpan (AAB).

First Report of Fungal Pathogens Causing Postharvest Crown Rot Disease in Bananas from Coastal Districts of Odisha

First Report of Fungal Pathogens Causing Postharvest Crown Rot Disease in Bananas from Coastal Districts of Odisha

EFFICACY ANTIMICROBIAL ENDOPHYTICS METABOLITES TO CONTROL SIGATOKA DISEASE (MYCOSPHAERELLA MUSICOLA) ON BANANAS IN NORTHERN SUMATERA

The secondary metabolites show diverse biological activities, including phytotoxic, antibacterial, antifungal, and antitumor. This study aimed to obtain secondary metabolites that are more effective in suppressing the development of Sigatoka disease in bananas. A field trial was performed to screen the antifungal metabolitesactivity of three isolates against Mycosphaerella musicola. This research used a randomised block design with four treatments and six replications. The results showed that the fastest incubation period was obtained at 14 days in the control treatment, and with Bacillus sp occurred after 30 days, 25 days in the treatment of Pseudomonas aeruginosa, and 40 days in the treatment of Trichoderma asperellum. The percentage of disease incidence and spot area on the leaves was most significant in the control treatment, 62,5% and 66,45%, then followed by Pseudomonas aeruginosa respectively, 41,67% and 34,48%, and the lowest disease incidence and spot area in the treatment, Trichodermasp were 25% and 21,78%, respectively. Further, the lowest disease severity was found in the secondary metabolite of Trichoderma asperellum at 23.36%, followed by Pseudomonas aeruginosa secondary metabolite at 32.57%. Meanwhile, the highest disease severity was found in the control treatment, with an average of 60.27%. Secondary metabolites of Bacillus sp, Trichoderma asperellum and Pseudomonas aeruginosa effectively suppress Sigatoka disease. The highest banana production was found in the secondary metabolite of Trichoderma asperellum, with a harvestweight of 13.98 kg, and the lowest harvest weight found in the control treatment was 11.90 kg

Designing innovative spatial strategies to control black leaf streak disease of banana through modelling approach

Experimentations to evaluate spatial strategies at the scale of a production basin to control Black leaf streak disease (BLSD) is difficult to implement. Modelling is a key approach to identify innovative scenarios to reduce the use of pesticides while efficiently and sustainably controlling the disease. To achieve this aim, we assess the efficacy of strategies directly based on fungicide applications or based on the deployment of resistant cultivars. For that, we adapted a published spatially-explicit model to simulate BLSD epidemics in a real 300-ha agricultural landscape of Costa-Rica. More than 11,000 simulations of strategies are undergoing and the best scenarios will be identified to be further tested in the field.

GC-MS metabolite profiling of Pseudocercospora fijiensis isolates resistant to thiabendazole.

Black Sigatoka is the most widespread banana disease worldwide. It is caused by Pseudocercospora fijiensis, a fungal pathogen known for developing resistance to fungicides such as thiabendazole. Despite the increasing costs associated with the use of chemicals to control this disease, the pathogen's mechanisms for fungicide resistance are not fully understood. The metabolite profiles of P. fijiensis isolates with different levels of resistance to thiabendazole were characterized by GC-MS. A total of 33 isolates were obtained from symptomatic banana plants and the sensitivity of each isolate to thiabendazole was assessed at 0, 1, 10, 100, 1000, and 10000 μg.mL-1. Then, the metabolite profile of each isolate was assessed using GC-MS. Metabolites such as hexadecanoic acid, tetradecanoic acid, octadecadienoic acid and octadecanoic acid were significantly over-accumulated in the presence of thiabendazole at 10 μg.mL-1. Phosphoric acid, L-proline, and D-allose increased in concentration with time in the presence of 100 μg.mL-1 of thiabendazole, and mannonic acid, 1-hexadecanol, D-sorbitol and tetracosanoic acid were only detected in the presence of the fungicide. Metabolic pathways including that of fructose, mannose metabolism, the biosynthesis of unsaturated fatty acids, and ABC transporters were upregulated in resistant isolates. Our findings show an increment of tetracosanoic (myristic) acid suggesting a possible β-tubulin-compensation mechanism in resistant isolates. The presence of myristic acid promoted the generation of diacylglycerol kinase δ which facilitated the production of β-tubulin in other studies. Additionally, important changes in the metabolite profiles were observed as soon as six hours after exposure to the fungicide showing an early response of the pathogen. To the best of our knowledge, this is the first report that describes the changes in the metabolite profile of P. fijiensis resistant to thiabendazole when exposed to the fungicide.

Utilizing Aerial Imagery and Deep Learning Techniques for Identifying Banana Plants Diseases

The primary agricultural pursuit in Malaysia centres around banana cultivation; however, this vital crop faces the daunting challenge of multiple diseases that hinder its growth. The adverse consequences of these diseases extend beyond the farms to impact the nation’s economy. To empower farmers with the tools to promptly identify and categorize these diseases, image processing techniques offer a valuable solution. This research leverages deep learning Convolutional Neural Networks (CNN) implemented through MATLAB in conjunction with a DJI drone. By harnessing this technology, the system can automatically detect and classify major banana diseases. The study meticulously fine-tuned several hyperparameters to achieve impressive training and testing accuracy levels. The results revealed that the model attained its highest training accuracy of 81.27% at epoch 8 and its lowest accuracy of 78.40% at epoch 4, demonstrating its potential to aid in early disease detection and classification in banana crops.

Symptomatology and Morpho-Cultural Characterization of Colletotrichum musae, a Causal Agent of Anthracnose Disease in Banana

The study focused on the identification and characterization of Colletotrichum musae as a significant post-harvest fungal pathogen causing anthracnose disease in bananas. Symptoms included sunken, water-soaked spots on infected tissues, leading to soft, red-brown to black-coloured spots with irregular shapes. The pathogen was isolated and cultured on Potato dextrose agar medium, and its pathogenicity was confirmed by inoculating healthy banana fruits, resulting in typical anthracnose-like spots. Cultural characteristics of C. musae on PDA revealed whitish to black colonies, and microscopic examination showed oblong to cylindrical, single-celled conidia. Acervuli, which were salmon-coloured initially and later turned dark brown to black, were observed on the lesions. The fungus exhibited maximum growth and sporulation on PDA, followed by oat meal agar and Richard’s agar. Additionally, the study highlighted the morphological features of C. musae, including septate, irregularly branched, and vacuolated mycelium. The findings contribute to understanding the pathology and characteristics of C. musae, providing valuable information for managing post-harvest anthracnose in bananas.

Assessment of Various Fungicides, Bioagents and Natural Substances on Anthracnose Disease of Banana

The research was conducted to minimize the activity of harmful microorganism which is responsible for deterioration of fruit quality. The eight treatments were taken during the in-vitro study from which viz., six fungicides and two bioagents were tested for fruit dip treatment against anthracnose of banana. As a result of study, the most effective treatment was found carbendazim 12 % + mancozeb 63 % WP, which is showing the least disease intensity (20.26 %) and the highest reduction in banana anthracnose (52.56 %). Carbendazim and propiconazole also demonstrated significant disease reduction. Among non-hazardous chemicals, chitosan was the most effective (31.11 % disease intensity, 34.24 % reduction), followed by edible paraffin wax and yeast. Hot water treatment showed the highest disease intensity (44.49 %) and the least disease control (20.86 %). The study concluded that, carbendazim 12 %+ mancozeb 63 % WP and chitosan was the most effective against the post-harvest anthracnose disease of banana.

Antibacterial Activities of Euphorbia hirta and Lantan camara Extracts on the Growth of Some Bacteria that Causes Banana Plant Disease

Bananas (Musa acuminata L.) are confronted with a number of challenges imposed by bacterial diseases which lead to huge yield losses. In order to improve the yields of the banana plantation, one of the recommended management strategies which would be inexpensive and environmentally friendly was developed. The objective of this study was to improve the sanitary state of banana plant. To achieve this objective, bacteria associated with the different banana organs were isolated on Nutrient Agar (culture medium) and their morphological identification was carried out based on the cultural characteristics and the colour of the bacterial walls observed under an optical microscope and using reference documents (bacteriological identification keys). Antibacterial activity of Lantana camara and Euphorbia hirta extracts were evaluated in vitro on agar medium aginst Xanthomonas campestris pv. Pseudomonas solanacearum and Ralstonia solanacearum. The results showed that the banana plant harbours a diversity of bacteria species, the most frequent being Ralstonia solanacearum as it was isolated from all infected organs. The yields of the equeous extacts of Euphorbia hirta and Lantana camara were particularly high (7% and 13%) respectively, compared to those of the ethanolic extracts which were lower. Aqueous extracts of Euphorbia hirta, at 50 mg/ml, had bactericidal activity against Ralstonia solanacearum and Pseudomonas celebensis. Aqueous extracts of Lantana camara, at concentrations of 25 mg/ml and 50 mg/ml, exhibited bactericidal activity against P. celebensis. Meanwhile, the ethanolic extracts of L. camara, at 50 mg/ml had bacteriostatic activity against the development of P. celebensis. Ethanolic extracts of E. hirta had bactericidal activity on the growth of Xanthomonas campestris at 25 mg/ml and 50 mg/ml. The same activity was obtained with P. celebensis at 50 mg/ml. These results suggest that the aqueous and ethanol extracts of the tested plants at high concentrations could be used as alternatives to chemical products in the fight against banana diseases especially Xanthomonas, Pseudomonas and Ralstonia. Hence further studies need to be undertaken in order to isolate the active compounds from these extracts with bactericidal potential.

Transcriptomic and metabolomic differences between banana varieties which are resistant or susceptible to Fusarium wilt.

Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense race 4 (Foc4), is the most lethal disease of bananas in Asia. To better understand the defense response of banana to Fusarium wilt, the transcriptome and metabolome profiles of the roots from resistant and susceptible bananas inoculated with Foc4 were compared. After Foc4 inoculation, there were 172 and 1,856 differentially expressed genes (DEGs) in the Foc4-susceptible variety (G1) and Foc4-resistant variety (G9), respectively. In addition, a total of 800 DEGs were identified between G1 and G9, which were mainly involved in the oxidation-reduction process, cell wall organization, phenylpropanoid biosynthesis, and lipid and nitrogen metabolism, especially the DEGs of Macma4_08_g22610, Macma4_11_g19760, and Macma4_03_g06480, encoding non-classical arabinogalactan protein; GDSL-like lipase; and peroxidase. In our study, G9 showed a stronger and earlier response to Foc4 than G1. As the results of metabolomics, lipids, phenylpropanoids and polyketides, organic acids, and derivatives played an important function in response to Fusarium wilt. More importantly, Macma4_11_g19760 might be one of the key genes that gave G9 more resistance to Foc4 by a lowered expression and negative regulation of lipid metabolism. This study illustrated the difference between the transcriptomic and metabolomic profiles of resistant and susceptible bananas. These results improved the current understanding of host-pathogen interactions and will contribute to the breeding of resistant banana plants.