Control Of Plant Diseases Research Articles

Transcriptome Analysis Reveals the Involvement of Mitophagy and Peroxisome in the Resistance to QoIs in Corynespora cassiicola.

Quinone outside inhibitor fungicides (QoIs) are crucial fungicides for controlling plant diseases, but resistance, mainly caused by G143A, has been widely reported with the high and widespread use of QoIs. However, two phenotypes of Corynespora casiicola (RI and RII) with the same G143A showed significantly different resistance to QoIs in our previous study, which did not match the reported mechanisms. Therefore, transcriptome analysis of RI and RII strains after trifloxystrobin treatment was used to explore the new resistance mechanism in this study. The results show that 332 differentially expressed genes (DEGs) were significantly up-regulated and 448 DEGs were significantly down-regulated. The results of GO and KEGG enrichment showed that DEGs were most enriched in ribosomes, while also having enrichment in peroxide, endocytosis, the lysosome, autophagy, and mitophagy. In particular, mitophagy and peroxisome have been reported in medicine as the main mechanisms of reactive oxygen species (ROS) scavenging, while the lysosome and endocytosis are an important organelle and physiological process, respectively, that assist mitophagy. The oxidative stress experiments showed that the oxidative stress resistance of the RII strains was significantly higher than that of the RI strains: specifically, it was more than 1.8-fold higher at a concentration of 0.12% H2O2. This indicates that there is indeed a significant difference in the scavenging capacity of ROS between the two phenotypic strains. Therefore, we suggest that QoIs' action caused a high production of ROS, and that scavenging mechanisms such as mitophagy and peroxisomes functioned in RII strains to prevent oxidative stress, whereas RI strains were less capable of resisting oxidative stress, resulting in different resistance to QoIs. In this study, it was first revealed that mitophagy and peroxisome mechanisms available for ROS scavenging are involved in the resistance of pathogens to fungicides.

Comprehensive Analysis of Corn and Maize Plant Disease Detection and Control Using Various Machine Learning Algorithms and Internet of Things

Comprehensive Analysis of Corn and Maize Plant Disease Detection and Control Using Various Machine Learning Algorithms and Internet of Things

PhyEffector, the First Algorithm That Identifies Classical and Non-Classical Effectors in Phytoplasmas.

Phytoplasmas are the causal agents of more than 100 plant diseases in economically important crops. Eleven genomes have been fully sequenced and have allowed us to gain a better understanding of the biology and evolution of phytoplasmas. Effectors are key players in pathogenicity and virulence, and their identification and description are becoming an essential practice in the description of phytoplasma genomes. This is of particular importance because effectors are possible candidates for the development of new strategies for the control of plant diseases. To date, the prediction of effectors in phytoplasmas has been a great challenge; the reliable comparison of effectoromes has been hindered because research teams have used the combination of different programs in their predictions. This is not trivial since significant differences in the results can arise, depending on the predictive pipeline used. Here, we tested different predictive pipelines to create the PhyEffector algorithm; the average value of the F1 score for PhyEffector was 0.9761 when applied to different databases or genomes, demonstrating its robustness as a predictive tool. PhyEffector can recover both classical and non-classical phytoplasma effectors, making it an invaluable tool to accelerate effectoromics in phytoplasmas.

Fixed Spraying Systems Application in Citrus Orchards: Nozzle Type and Nozzle Position Effects on Droplet Deposition and Pest Control

Pesticide application is an essential means of controlling plant diseases and pests in citrus orchards. In recent years, fixed spraying systems have gradually been used as alternatives to traditional sprayers and manual sprayers in some hilly citrus orchards. In this paper, influences of fixed system spraying parameters, such as droplet size and spraying height, on spraying quality were elucidated and analyzed. The performances of two nozzle types, pressure-swirl nozzles and fixed spray plate sprinklers, were assessed and compared by effective droplet coverage ratio (DCR), droplet distribution uniformity coefficient of variation (CV), and droplet penetration ratio (DPR). The results showed that appropriately increasing droplet size and spraying height could improve the DCR and distribution uniformity of pressure-swirl nozzles. The DCR and distribution uniformity of fixed spray plate sprinklers had a positive correlation with droplet size, while spraying height had no significant effect on these variables. Additionally, with the increase in droplet size, DPR initially increased and then gradually decreased. The optimized results showed that the optimal parameters for pressure-swirl nozzles were a droplet size of 240 μm and spraying height of 100 cm, while for fixed spray plate sprinklers, the results were a droplet size of 240 μm and spraying height of 50 cm. Comparison results showed that the spraying quality of fixed spray plate sprinklers was better overall, with values of DCR, CV, and DPR being 37.15%, 24.20%, and 71.67%, respectively, while the corresponding values for pressure-swirl nozzles were 39.65%, 35.41%, and 56.02%. Based on the above results and the occurrence rule of citrus pests and disease, the optimal spraying parameters of fixed spraying systems were selected to control the Asian citrus psyllid Diaphorina citri. Furthermore, the effect of fixed spraying systems on controlling Diaphorina citri reached the maximum at 3 days after spraying, which was 97.83%, and the effect declined at 14 days after spraying, which was 85.47%. This study provides valuable scientific references for guiding the application of fixed spraying systems in hilly citrus orchards.

Chitosan- and gallic acid-based (NPF) displayed antibacterial activity against three Pseudomonas spp. plant pathogens and boosted systemic acquired resistance in kiwifruit and olive plants.

Pseudomonas syringae pv. actinidiae (Psa), P. syringae pv. tomato (Pst) and P. savastanoi pv. savastanoi (Psav) are bacterial plant pathogens with worldwide impact that are mainly managed by the preventive application of cupric salts. These are dangerous for ecosystems and have favoured the selection of resistant strains, so they are candidates to be replaced in the next few years. Thus, there is an urgent need to find efficient and bio-based solutions to mitigate these bacterial plant diseases. Nanotechnology could represent an innovative way to control plant diseases, providing alternative solutions to the agrochemicals traditionally employed, thanks to the formulation of the so-called third-generation and nanotechnology-based agrochemicals. In this work, a novel nanostructured formulation (NPF) composed of cellulose nanocrystals (CNC) as carrier, high amylose starch (HAS) as excipient, and chitosan (CH) and gallic acid (GA) as antimicrobials, was tested at 2% in vitro and in vivo with respect to the three different Pseudomonas plant pathogens. In vitro agar assays demonstrated that the NPF inhibited ≤80% Psa, Pst and Psav. Moreover, the NPF did not decrease biofilm synthesis and it did not influence bacterial cells flocculation and adhesion. On plants, the NPF displayed complete biocompatibility and boosted the transcript levels of the major systemic acquired resistance responsive genes in kiwifruit and olive plants. This works provides novel and valuable information regarding the several modes-of-action of the novel NPF, which could potentially be useful to mitigate Psa, Pst and Psav infections even in organic agriculture. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Marine Bacillus as a potent biocontrol agent against Fusarium oxysporum f.sp. ciceris

The most severe chickpea diseases in the world is Fusarium wilt, which is brought on by the soil-borne fungus Fusarium oxysporum ciceris (FOC). FOC can reduce a chickpea crop's output by up to 100 %. Various management strategies have been employed out of which biological method is most suitable and effective. In the current study, the effectiveness of marine Bacillus licheniformis as a biocontrol agent against Fusarium infection in chickpea crops is investigated. Marine organisms are known to produce many antibiotics and controlling human pathogens. The current study aims at evaluating the effect of marine B. licheniformis against the chickpea pathogen (FOC). In vitro evaluations of glucanase and chitinase production as well as antifungal activity were done. B. licheniformis prevented development of fungal mycelia. Marine B. licheniformis was able to reduce disease index to 0 in chickpea. Three different conditions were used for the pot trial: control (T1), FOC treated (T2), and both Bacillus and FOC treated (T3). In pot experiment, T3 demonstrated 6.29 % increase in plant weight and 13.25 % increase in plant height. Despite the presence of FOC in T3, B. licheniformis was able to boost the growth of the plant while preventing FOC infection. The results showed that B. licheniformis has bio-control capabilities defending chickpea against disease and also improves its growth indicating that marine microbes are potent biocontrol agents. This study can open new avenues of using marine microbes in controlling plant disease.

The Characterization of the Inhibitory Substances Produced by Bacillus pumilus LYMC-3 and the Optimization of Fermentation Conditions

Bacillus pumilus plays a very important role in the biological control of plant diseases. In this study, we conducted indoor biocontrol experiments using the LYMC-3 strain of B. pumilus to assess its efficacy against poplar canker and tea gray blight. Simultaneously, we explored the optimal fermentation conditions for the production of inhibitory substances against Phomopsis macrospora and Pestalotiopsis vesicolor. Subsequently, the inhibitory substances were extracted crudely and subjected to a preliminary investigation of their properties. The results of the indoor biocontrol experiments showed that the LYMC-3 strain exhibited disease prevention rates of 44.12% and 48.59% against poplar canker and tea gray blight, respectively. The fermentation optimization experiment showed that a culture medium containing 10 g/L of glucose, 15 g/L of tryptone, and 5 g/L of sodium chloride favored the production of inhibitory substances via the LYMC-3 strain. Among the crude extracts obtained, the non-protein extracts demonstrated the most obvious inhibitory effects. Furthermore, the inhibitory substances exhibited high polarity, excellent thermal stability, and high sensitivity to strong acids and bases. This study establishes a theoretical foundation for the purification and identification of inhibitory substances using the LYMC-3 strain. Additionally, it contributes to elucidating biological control mechanisms and facilitates the application of the LYMC-3 strain in production.

A review of the efficacy of biofumigation agents in the control of soil-borne plant diseases

A review of the efficacy of biofumigation agents in the control of soil-borne plant diseases

Systemic resistance induced by plant growth-promoting rhizobacteria in Bhut Jolokia (Capsicum chinense Jacq.) suppressed the collar rot disease

Collar rot disease caused by Rhizoctonia solani is a major constraint to the commercial cultivation of Bhut Jolokia (Capsicum chinense Jacq.) in North-East India. However, the management of the disease is not addressed comprehensively in this plant. Some plant growth-promoting rhizobacteria (PGPR) could control plant diseases by triggering induction of resistance systemically, and emerge as a highly promising approach to reduce the use of chemical fungicides. Therefore, five selected PGPRs were tested for plant growth promotion and induced systemic resistance (ISR) for controlling the disease. Induced systemic resistance was determined in vivo condition. Confocal laser scanning microscopic observation was done to see any harmful effects on cells in the induced plant. The PGPRs could significantly improve plant growth as well as suppress the disease and boost defense-related enzymes activity in the induced plants. Bacillus megaterium JPR68 triggered the maximum ISR in the plant. Expression of the defense-related genes was analyzed which were highly expressed in ISR plants. Microscopic observation revealed that no internal changes occurred in PGPR treated plant cells similar to the untreated plant, and indicated no harmful effect of the bacteria in the host cell. The study demonstrates the possible application of B. megaterium JPR68 as a biocontrol agent for sustainable management of the disease. To our knowledge, this is the first report of ISR against any fungal disease in Bhut Jolokia.

Genome mining conformance to metabolite profile of Bacillus strains to control potato pathogens

Biocontrol agents are safe and effective methods for controlling plant disease pathogens, such as Fusarium solani, which causes dry wilt, and Pectobacterium spp., responsible for potato soft rot disease. Discovering agents that can effectively control both fungal and bacterial pathogens in potatoes has always presented a challenge. Biological controls were investigated using 500 bacterial strains isolated from rhizospheric microbial communities, along with two promising biocontrol strains: Pseudomonas (T17-4 and VUPf5). Bacillus velezensis (Q12 and US1) and Pseudomonas chlororaphis VUPf5 exhibited the highest inhibition of fungal growth and pathogenicity in both laboratory (48%, 48%, 38%) and greenhouse (100%, 85%, 90%) settings. Q12 demonstrated better control against bacterial pathogens in vivo (approximately 50%). Whole-genome sequencing of Q12 and US1 revealed a genome size of approximately 4.1 Mb. Q12 had 4413 gene IDs and 4300 coding sequences, while US1 had 4369 gene IDs and 4255 coding sequences. Q12 exhibited a higher number of genes classified under functional subcategories related to stress response, cell wall, capsule, levansucrase synthesis, and polysaccharide metabolism. Both Q12 and US1 contained eleven secondary metabolite gene clusters as identified by the antiSMASH and RAST servers. Notably, Q12 possessed the antibacterial locillomycin and iturin A gene clusters, which were absent in US1. This genetic information suggests that Q12 may have a more pronounced control over bacterial pathogens compared to US1. Metabolic profiling of the superior strains, as determined by LC/MS/MS, validated our genetic findings. The investigated strains produced compounds such as iturin A, bacillomycin D, surfactin, fengycin, phenazine derivatives, etc. These compounds reduced spore production and caused deformation of the hyphae in F. solani. In contrast, B. velezensis UR1, which lacked the production of surfactin, fengycin, and iturin, did not affect these structures and failed to inhibit the growth of any pathogens. Our findings suggest that locillomycin and iturin A may contribute to the enhanced control of bacterial pectolytic rot by Q12.

Evaluation of Bacillus sp. strains for biological control of gummy stem blight, Didymella bryoniae (Auersw.) in watermelon (Citrullus lanatus)

The gummy stem blight caused by Didymella bryoniae (Auersw.) is a major and destructive disease of watermelon in Vietnam. Bacillus species have been used to control plant diseases as biological control agents. This study was carried out at the Department of Crop Production and Plant Protection, Phu Yen province, Vietnam during 2020 – 2021 to determine fungal inhibition of D. bryoniae DB-03 in in vitro and disease suppression of gummy stem blight under greenhouse conditions by Bacillus sp. strains namely S1A1, S1F3, S13E3, S18F11, and S20D12, which were isolated from stem-base of groundnut in central Vietnam. Results revealed that, all the tested strains of Bacillus sp. showed good inhibitory effect on the hyphal growth of D. bryoniae strain DB-03 in potato dextrose broth. Among the strains, Bacillus sp. S20F12 had highest inhibition of the mycelia growth of D. bryoniae strain DB-03 with an antagonistic efficiency of 60.7% at 10 days after fungal inoculation. Bacillus sp. reduced gummy stem blight under greenhouse conditions. At 21 days after fungal inoculation, disease incidences were low in the plants treated with Bacillus sp. S18F11 and S20D12 by 60.0% and 63.3%, respectively. The results would contribute to the knowledge of antagonistic activities of the Bacillus to optimize the biological control programme against D. bryoniae.

Development of Trichoderma Formulation and Application to Control Durian Anthracnose Disease

Anthracnose is a plant fungal disease that damages both quantitative and qualitative crop yields. Biological control of plant disease is an alternative method enabling reduced use of chemicals. The objective of this research was to develop a formulation of Trichoderma for controlling plant anthracnose disease. The efficacy of T. asperellum MSU007 in controlling Colletotrichum sp. by dual culture technique showed that T. asperellum MSU007 was able to inhibit the mycelium growth of Colletotrichum sp. with 50.76 - 74.85 % inhibition. Three formulations of T. asperellum MSU007 were developed. The viability of T. asperellum MSU007 in the formulation after drying at 45 °C showed that the viabilities of formulation 2 and 3 were not significantly different at 5.26×108 and 5.30×108 cfu/g, respectively, while that of formulation 1, the viability of T. asperellum MSU007 was reduced to 3.73×106 cfu/g. After storage at room temperature for 30 days, formulations 2 and 3 did not result in significantly different viability of T. asperellum MSU007 at 4.40×108 and 4.90×108 cfu/g, respectively, and after 90 days of storage at room temperature, it was found that only formulation 3 did not decrease T. asperellum MSU007 viability at 4.33×108 cfu/g. The efficacy of Trichoderma bioproduct in inhibiting anthracnose pathogens on durian leaves was tested. It was found that spraying formulation 3 after inoculation of Colletotrichum sp. resulted in the least anthracnose severity at 15.67 ± 4.04 %, which was significantly different from other treatments including the use of carbendazim. However, it is necessary to further study the efficacy of Trichoderma formulation in the inhibition of durian anthracnose pathogens in field conditions in order to be able to use this bioproduct in future disease control. HIGHLIGHTS This research developed an effective Trichoderma bioproduct to control the durian anthracnose causative agent Colletotrichum spp. which has sufficient potential to be developed and applied in the control of this disease, replacing the use of chemicals in the future. GRAPHICAL ABSTRACT

Broad-spectrum antagonistic potential of Bacillus spp. volatiles against Rhizoctonia solani and Xanthomonas oryzae pv. oryzae.

Rhizoctonia solani and Xanthomonas oryzae pv. oryzae (Xoo) are the two major diseases affecting the quality and quantity of rice production. In the current study, volatile organic compounds (VOCs) of Bacillus spp. were used as green biocontrol agents for plant diseases. In in vitro experiments, Bacillus spp. FZB42, NMTD17, and LLTC93-VOCs displayed strong antimicrobial volatile activity with inhibition rates of 76, 66, and 78% for R. solani and 78, 81, and 76% for Xoo, respectively, compared to control. The synthetic VOCs, namely Pentadecane (PDC), Benzaldehyde (BDH), 1,2-Benz isothiazol-3(2H)-one (1,2-BIT), and mixture (MIX) of VOCs showed high volatile activity with inhibition rates of 86, 86, 89, and 92% against R. solani and 81, 81, 82, and 86%, respectively, against Xoo as compared to control. In addition, the scanning and transmission electron microscopes (SEM and TEM) analyses were performed to examine the effect of Bacillus and synthetic VOC treatments on R. solani and Xoo morphology. The analysis revealed the deformed and irregularized morphology of R. solani mycelia and Xoo cells after VOC treatments. The microscopic analysis showed that the rapid inhibition was due to severe oxidative productions inside the R. solani mycelia and Xoo cells. By using molecular docking, it was determined that the synthetic VOCs entered the active binding site of trehalase and NADH dehydrogenase proteins, causing R. solani and Xoo cells to die prematurely and an accumulation of ROS. In the greenhouse experiment, FZB42, NMTD17, and LLTC93-VOCs significantly reduced the lesions of R. solani 8, 7, and 6 cm, and Xoo 7, 6, and 6 cm, respectively, then control. The synthetic VOCs demonstrated that the PDC, BDH, 1,2-BIT, and MIX-VOCs significantly reduced R. solani lesions on leaves 6, 6, 6, and 5 cm and Xoo 6, 5, 5, and 4 cm, respectively, as compared to control. Furthermore, plant defence-related genes and antioxidant enzymes were upregulated in rice plants. These findings provide novel mechanisms by which Bacillus antimicrobial VOCs control plant diseases.

A Binary Neural Network with Dual Attention for Plant Disease Classification

Plant disease control has long been a critical issue in agricultural production and relies heavily on the identification of plant diseases, but traditional disease identification requires extensive experience. Most of the existing deep learning-based plant disease classification methods run on high-performance devices to meet the requirements for classification accuracy. However, agricultural applications have strict cost control and cannot be widely promoted. This paper presents a novel method for plant disease classification using a binary neural network with dual attention (DABNN), which can save computational resources and accelerate by using binary neural networks, and introduces a dual-attention mechanism to improve the accuracy of classification. To evaluate the effectiveness of our proposed approach, we conduct experiments on the PlantVillage dataset, which includes a range of diseases. The F1score and Accuracy of our method reach 99.39% and 99.4%, respectively. Meanwhile, compared to AlexNet and VGG16, the Computationalcomplexity of our method is reduced by 72.3% and 98.7%, respectively. The Paramssize of our algorithm is 5.4% of AlexNet and 2.3% of VGG16. The experimental results show that DABNN can identify various diseases effectively and accurately.

Recent Advances in Mechanisms Underlying Defense Responses of Horticultural Crops to Botrytis cinerea

Horticultural crops are a crucial component of agriculture worldwide and have great economic value. The notorious plant fungal pathogen Botrytis cinerea can cause gray mold disease in over 200 horticultural crops, leading to severe economic losses. Investigating the mechanisms underlying plant defense responses to pathogens is crucial for developing new strategies for effectively controlling plant diseases, and much progress has occurred in the mechanisms underlying defense responses of horticultural crops to B. cinerea mainly due to the completion of genome sequencing and the establishment of efficient tools for functional genomics. In this review, recent progress in mechanisms underlying defense responses and natural products that can enhance the resistance of horticultural crops to B. cinerea are summarized, and future research directions are also discussed.

Design, synthesis and antibacterial activity of coumarin-3-carboxylic acid derivatives containing acylhydrazone moiety

Plant diseases caused by bacteria lead to enormous yield and economic losses in agricultural production. To develop innovative bactericides for controlling plant disease, a series of coumarin-3-carboxylic acid derivatives containing acylhydrazone thioether/sulfoxide were designed and synthesized by utilizing the principles of bioisosterism and active splicing. The bactericidal activities of these derivatives were subsequently evaluated. The result indicated that E2 exhibited the highest antibacterial activities in vitro against Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Acidovorax citrulli, with EC50 values of 2.97, 1.17, and 1.23 µg/mL, respectively. Moreover, in vivo experiments showed that E2 exhibited robust protective properties against Ralstonia solanacearum, and Acidovorax citrulli, with efficacies of 72.52 % and 63.90 %, respectively, at a concentration of 100 µg/mL, which was comparable to the positive control kasugamycin at the same concentration. Scanning electron microscopy analysis revealed that E2 induced changes in the cellular morphology of Acidovorax citrulli, such as shrinkage and collapse. Subsequent investigation revealed that E2 had the capacity to compromise the structural stability of the bacterial membrane of Ralstonia solanacearum. This study represents the first report on the antibacterial activities of this series of coumarin-3-carboxylic acid derivatives containing the acylhydrazone thioether/single-sulfoxide moiety, and the results suggest that coumarin-3-carboxylic acid derivatives containing the acylhydrazone single-sulfoxide may hold potential as effective antibacterial agents. And coumarin-3-carboxylic acid derivatives exhibited promise as plant bacterial agent to prevent rice bacterial leaf blight, tomato bacterial wilt, and melon bacterial fruit blotch.

Replacing Mancozeb with Alternative Fungicides for the Control of Late Blight in Potato.

Mancozeb (MZ) is a broadly used fungicide for the control of plant diseases, including late blight in potatoes caused by the oomycete Phytophthora infestans (Mont.) De Bary. MZ has been banned for agricultural use by the European Union as of January 2022 due to its hazards to humans and the environment. In a search for replacement fungicides, twenty-seven registered anti-oomycete fungicidal preparations were evaluated for their ability to mitigate the threat of this disease. Fourteen fungicides provided good control (≥75%) of late blight in potted potato and tomato plants in growth chambers. However, in Tunnel Experiment 1, only three fungicides provided effective control of P. infestans in potatoes: Cyazofamid (Ranman, a QiI inhibitor), Mandipropamid (Revus, a CAA inhibitor), and Oxathiapiprolin + Benthiavalicarb (Zorvek Endavia, an OSBP inhibitor + CAA inhibitor). In Tunnel Experiment 2, these three fungicides were applied at the recommended doses at 7-, 9-, and 21-day intervals, respectively, totaling 6, 4, and 2 sprays during the season. At 39 days post-inoculation (dpi), control efficacy increased in the following order: Zorvec Endavia > Ranman > Revus > Mancozeb. Two sprays of Zorvec Endavia were significantly more effective in controlling the blight than six sprays of Ranman or four sprays of Revus. We, therefore, recommend using these three fungicides as replacements for mancozeb for the control of late blight in potatoes. A spray program that alternates between these three fungicides may be effective in controlling the disease and also in avoiding the build-up of resistance in P. infestans to mandipropamid and oxathiapiprolin.

Recent advances ofmicroneedles biosensors for plants.

As the lack of plants can affect the energy operation of the entire ecosystem, monitoring and improving the health status of plants is crucial. However, ordinary biosensing platforms lack accuracy and timeliness in monitoring plant growth status. In addition, the prevention and control of plant diseases often involve spraying and administering drugs, which is inefficient and prone to pollution. Microneedles have unique dimensions and shapes, and they have significant advantages as biosensors in the fields of sensing, detection, and drug delivery. Recent evidence suggests that microneedle biosensors can become effective tools for plant diagnosis and treatment. In this review, the comprehensive development of the application of microneedle biosensors in the field of plants is introduced, as well as their manufacturing processes and sensing and detection functions. Furthermore, the application of microneedle biosensors in this field is discussed, and future development directions are proposed.

Agribusiness development strategy of papaya calina (carica papaya l.)

Papaya Calina (Carica papaya L.) is one of the main commodities in Cidolog Village, Cidolog District, Sukabumi Regency. Since 2020, Papaya plantation in Cidolog has remained static, and production has even decreased in 2020-2021 while national production increased. The research was conducted in December 2021 to identify the internal and external conditions in papaya agribusiness in Cidolog, and formulate strategies to develop the business. Internal and external environment mapping was obtained through observation and in-depth interviews with the farmer group. Assessment of the IFE and EFE matrices, and strategy formulation using SWOT Matrix, were obtained from interviews with five experts. Environment analysis shows that the papaya agribusiness in Cidolog Village has prospects for further development with an IFE value of 2.51 and an EFE of 2.64. The position of Calina's papaya agribusiness in IE matric is in cell 5 with a “guard and sustain” strategy. SWOT Matrix formulates 8 strategies namely 1) Expansion of land, 2) Increasing the role and dynamics of farmer groups, 3) Strengthening capabilities and access to networking, 4) Processing of inferior papaya into processed products, 5) Expansion of information and promotion of Papaya Calina Cidolog on the village website, District website, social media, and exhibitions, 6) Training on pest and plant disease control and cultivation practices in general, 7) Proposing road repairment to the relevant local government, and 8) opening the new market to supermarkets and a fruit shop.

Exploration of the Biocontrol Activity of Bacillus atrophaeus Strain HF1 against Pear Valsa Canker Caused by Valsa pyri.

Valsa pyri-induced pear Valsa canker is among the most prevalent diseases to impact pear quality and yields. Biocontrol strategies to control plant disease represent an attractive alternative to the application of fungicides. In this study, the potential utility of Bacillus atrophaeus strain HF1 was assessed as a biocontrol agent against pear Valsa canker. Strain HF1 suppressed V. pyri mycelium growth by 61.20% and induced the development of malformed hyphae. Both culture filtrate and volatile organic compounds (VOCs) derived from strain HF1 were able to antagonize V. pyri growth. Treatment with strain HF1-derived culture filtrate or VOCs also induced the destruction of hyphal cell membranes. Headspace mixtures prepared from strain HF1 were analyzed, leading to the identification of 27 potential VOCs. Of the thirteen pure chemicals tested, iberverin, hexanoic acid, and 2-methylvaleraldehyde exhibited the strongest antifungal effects on V. pyri, with respective EC50 values of 0.30, 6.65, and 74.07 μL L-1. Fumigation treatment of pear twigs with each of these three compounds was also sufficient to prevent the development of pear Valsa canker. As such, these results demonstrate that B. atrophaeus strain HF1 and the volatile compounds iberverin, hexanoic acid, and 2-methylvaleraldehyde exhibit promise as novel candidate biocontrol agents against pear Valsa canker.