Reduced Disease Incidence Research Articles

Sensitivity of Mucor piriformis to Natamycin and Efficacy of Natamycin Alone and with Salt and Heat Treatments Against Mucor Rot of Stored Mandarin Fruit.

Mucor rot caused by Mucor piriformis is an emerging postharvest disease of mandarin fruit in California. Natamycin is a newly registered biofungicide for postharvest use on citrus and some other fruits. In the study, baseline sensitivity to natamycin in 50 isolates of M. piriformis was determined in vitro. The mean EC50 (effective concentration to inhibit sporangiospore germination by 50%) and MIC (minimum inhibitory concentration to inhibit mycelial growth by 100%) values were 0.59 μg/ml and less than 1.0 μg/ml, respectively. Natamycin at the label rate of 920 μg/ml alone or in combination with 3% potassium sorbate (PS) or 3% sodium carbonate (SC) applied at 20 or 50°C was evaluated for control of Mucor rot on inoculated 'Tango' mandarin fruit. Natamycin alone reduced Mucor rot incidence on stored mandarin fruit from 100% among nontreated control fruit to approximately 30%, a reduction of more than 70% compared to the nontreated control, while 3% PS and 3% SC had no to little control. When applied at 50°C, natamycin and 3% PS reduced Mucor rot incidence by 65.0 and 31.2%, respectively; while natamycin in combination with 3% PS reduced disease incidence by 92.5% compared to the nontreated control after 2 weeks of storage at 5°C. This combined treatment remained effective even when the application of the treatment was delayed for 6 and 12 h after inoculation. However, the effectiveness of the treatments declined when storage was extended to 3 or 4 weeks. Natamycin can be an effective tool to control Mucor rot on mandarin fruit, and minimizing the period of extended storage could help maintain the control efficacy of natamycin.

From symptom onset to treatment initiation: protocol for a narrative study exploring the journey of older adults with tuberculosis in the English Midlands, UK

IntroductionTime from symptom onset to treatment initiation in tuberculosis (TB) remains stubbornly prolonged despite reductions in disease incidence. Delays may contribute to increased morbidity, mortality, onward spread of disease and...

Suppression of Phytophthora capsici in Chile Pepper Using Brassica juncea and Hordeum vulgare Cover Crop Residues and Trichoderma harzianum as a Biocontrol Agent.

Phytophthora blight, caused by Phytophthora capsici, is a serious disease of many vegetable crops worldwide. In New Mexico, U.S.A., the disease affects chile pepper (Capsicum annuum L.), a major crop in the state. There is no single tool that effectively controls the disease. Continuous research is needed in identifying combination of tools that can reduce the impact of Phytophthora blight. We explored the potential of combining cover crops and biocontrol agents to reduce soilborne diseases. This study aimed to evaluate the effects of Indian mustard (Brassica juncea L.) cover crop on the antagonistic ability of Trichoderma harzianum against P. capsici in vitro and to quantify the impacts of combining soil amendment with residues from B. juncea and barley (Hordeum vulgare L.) cover crops and plastic covering on infection of chile pepper seedlings by P. capsici under greenhouse conditions. Volatiles from macerated tissue of B. juncea significantly reduced P. capsici and T. harzianum growth in the absence of soil by 89.0 and 79.0%, respectively. When incorporated in soils, volatiles from macerated tissue of B. juncea significantly reduced P. capsici and T. harzianum by 33.4 and 7.8%, respectively. T. harzianum was more resilient to B. juncea biofumigation than P. capsici. Significant reduction in disease incidence was observed with B. juncea-fumigated soil, while no disease suppression was observed with soil incorporation of H. vulgare residues. Covering soil with plastic was necessary for increasing the efficacy of B. juncea biofumigation.

Induction of defense-related enzymes and enhanced disease resistance in rice against Sarocladium oryzae by Bacillus cereus RBS-57

Bacillus species have been identified as effective bioagents and plant growth boosters in rice. Currently, there is limited research on the effectiveness of Bacillus strains in managing the sheath rot disease of rice caused by Sarocladium oryzae, a significant threat to rice-cultivating areas in India. The aim of this study was to evaluate the efficacy of Bacillus spp. to control the sheath rot disease and promote growth in rice plants. We investigated the in vitro antagonistic activity and growth-promoting potential of eighty-four Bacillus spp. against S. oryzae. Ten efficient strains were carefully selected and analyzed at the molecular level based on their capacity for antagonism and growth promotion. A PCR study of the potential strains has revealed the presence of lipopeptide genes that produce bacilysin, bacillomycin, iturin, surfactin, subtilin, subtilosin and fengycin. Among the strains, RBS-57 had the highest mycelial growth inhibition (74.44 %) of the pathogen as well as the highest number of antibiotic genes (6). The efficacy of talc and liquid formulations of Bacillus strains BS-5, RBS-57, and RBS-3 was further tested against sheath rot disease. Results indicated that a combined application of seed treatment + seedling dip + foliar spray of RBS-57 liquid formulation under pot culture conditions, showed a considerable reduction in the incidence of sheath rot disease, followed by BS-5 and RBS-3. Similarly, a significant increase in the plant growth attributes and yield was observed with RBS-57, when compared to the other treatments. Enzymatic activities such as PO, PPO, PAL, CAT and SOD were induced in the rice sheath by B. cereus (RBS-57) treatment. Real-time expression analysis was performed to validate the fold changes in defense enzymes and reactive oxygen species. The effectiveness of RBS-57 liquid formulation in reducing disease incidence was demonstrated when applied as a combination of seed treatment @ 10 ml/l + seedling dip @ 10 ml/l + foliar spray @ 10 ml/l. Moreover, higher defense enzyme activities, maximum plant growth promotion and higher yield were reported with RBS-57 treatment. This study has the potential to be exploited to manage sheath rot disease in an eco-friendly and sustainable manner.

Comparative analysis of isonicotinic acid, l-ascorbic acid and calcium chloride on the induction of innate immunity and secondary metabolite production in Catharanthus roseus (L.) G. Don for management of biotic and oxidative stress

Catharanthus roseus (L.) G. Don is an ornamental and pharmacologically important plant. It contains large amount of indole alkaloids having pharmaceutical activities. Production of vinblastine and vincristine, two important anti-cancerous secondary metabolites of C. roseus, are very less and hampered due to pathogen invasion. To overcome this problem here attempt has been made to boost innate immunity and secondary metabolite production in C. roseus by foliar application of three eco-friendly elicitors viz. Calcium chloride (CaCl2), l-Ascorbic acid (L-AA) and Isonicotinic acid (INA), each at two different concentrations. Augmentation of immune responses was observed in terms of increased production of defense related enzymes like PPO (polyphenol oxidase), PO (peroxidase), PAL (phenylalanine ammonia lyase assay), and β-1,3 glucanase; defense related compound production (total flavonoid and phenol content) and antioxidant enzyme activity (ascorbate peroxidase, APX and catalase, CAT) in C. roseus plant. Increased defense responses were noted in INA (1.25 mM), l-AA (5 mM) and CaCl2 (0.5 %) treated plants compared to control. Same concentrations of elicitors were also found effective in the induction of vinblastine and vincristine production which was detected by both qualitative (using dragendroff reagent) and quantitative methods using LC-MS (Liquid Chromatography-Mass Spectrometry). During this study, nitric oxide (NO) production was also found increased in elicitor treated plants and indicating its signaling role. Finally, challenge inoculation with Alternaria alternata showed significantly reduced disease incidence in elicitor treated plants which indicates their potentiality to combat against this pathogen.

Efficacy of different fungicides on wheat blast disease caused by M. oryzae pv. triticum in vitro and vivo condition

The experiment was studied to evaluate the fourteen different fungicides against M. oryzae pv. triticum in laboratory and pot experiment from August 2016 to October 2017. The result of the in-vitro evaluation showed that a 100% reduction of radial mycelial growth was obtained in Amiscore 32.5 SC, Bavistin DF, Cabrio Top, Xtracare 300 EC, Nativo 75 WG, Provax 200 WP and Trooper 75 WP. Nativo 75 WG (0.2%) revealed the highest (85.38%) reduction of disease incidence over control while Provax 200 WP (0.3%) showed an efficacy of 82.14% in reducing disease incidence in the pot experiment. The lowest (3.70%) disease severity was found in Nativo 75 WG, and Provax 200 WP also exhibited 4.40% disease severity. A maximum number of healthy grain/ear (16.40) was observed in Nativo 75 WG, and Provax 200 WP was demonstrated with healthy grain (15.00), which was close to Nativo 75 WG. In grain weight/ear, Nativo 75 WG (0.2%) led to an impressive increase of 160.47% over control.

Comparative evaluation of physiological and biochemical changes in black pepper plants infected by Colletotrichum siamense in response to Trichoderma viride and T. harzianum application

Black pepper (Piper nigrum L.) holds a prominent position as a globally renowned spice. Pepper vines are susceptible to various diseases, among which anthracnose stands out as a highly detrimental disease capable of severely affecting both foliage and berries. The current study was carried out to find out the effectiveness of Trichoderma viride and T. harzianum to manage the anthracnose disease of black pepper and to assess the plant innate defense response to these biocontrol agents application. Results demonstrated that foliar application of T. viride and T. harzianum, either individually or in combination, resulted in a significant reduction of disease incidence by 59.3, 67.2, and 69.8% respectively, compared to untreated infected plants. Additionally, disease severity was lowered to 71.1, 75.6, and 77.8% respectively in the treated groups. Simultaneously, these treatments exhibited a substantial promotion of black pepper growth, as indicated by increased leaf area index, number of leaves, shoot length and root length compared to the control. Physiological and biochemical analyses revealed a notable increase in chlorophyll (Chl a, Chl b, Total chl) and flavonoid content, coupled with reductions in hydrogen peroxide (H2O2), and Malondialdehyde concentrations at 48 and 96 h after treatment. Furthermore, evaluation of the superoxide dismutase (SOD) revealed a significant increase in SOD enzymatic activity following the application of the fungi, whether applied individually or in combination. Consequently, it was inferred that both T. viride and T. harzianum effectively protected black pepper plants from anthracnose by suppressing disease incidence, enhancing chlorophyll content, improving overall plant health, and inducing the innate defense system. These findings highlight the multifaceted advantages offered by T. viride and T. harzianum in terms of plant protection and growth promotion.

Nutritional and Anti-nutritional Compositions of Rice Bran as a Potential Animal Feed

Rice bran, a byproduct of rice milling, is a valuable ingredient in animal feed formulations, particularly poultry feed, due to its high energy content, nutritional benefits, and ability to meet bird protein requirements. Rice bran, analyzed according to AOAC standards, is rich in energy, protein, and minerals like calcium, phosphorus, and potassium, essential for poultry health. Its high-fat profile, with higher unsaturated fatty acids, has positive effects on poultry health, including improved egg quality, enhanced immune function, and reduced disease incidence.
 Rice bran has a moisture content of 4.3338% and a crude fibre content of 16.3675%. It has a total ash content of 18.8126% and a crude fat content of 12.0354%, 12.3676%, and 12.6180%. The compositions of rice bran were compared favourably to commercial feed formulations for starter, grower, and finisher meals. The crude fat content is 12.0354%, 12.3676%, and 12.6180%, while the crude protein content is 26.2688%, 27.5813%, and 21.8906%. The carbohydrate contents are 41.2677%, 41.8456% and 49.4032% and the total ash content was measured at 10.4377%, 6.3672% and 4.4905%.
 The rice bran's trace mineral composition includes calcium, magnesium, potassium, phosphorus, sodium, iron, and copper. Heavy metals like lead and cadmium are below the detection limit of the M5 Thermo Scientific atomic absorption Spectrometer. The anti-nutrient composition includes anthraquinones, phenolics, tannins, saponins, and phytic acid.
 Rice bran in poultry feed formulations enhances nutritional needs and outperforms commercial feeds. In addition, to increase nutrient availability, it is necessary to add a phytase enzyme in order to break down phytic acid.

Characterization of Durum Wheat Resistance against Septoria Tritici Blotch under Climate Change Conditions of Increasing Temperature and CO2 Concentration

Wheat interactions against fungal pathogens, such as Zymoseptoria tritici, are affected by changes in abiotic factors resulting from global climate change. This situation demands in-depth knowledge of how predicted increases in temperature and CO2 concentration ([CO2]) will affect wheat—Z. tritici interactions, especially in durum wheat, which is mainly grown in areas considered to be hotspots of climate change. Therefore, we characterized the response of one susceptible and two resistant durum wheat accessions against Z. tritici under different environments in greenhouse assays, simulating the predicted conditions of elevated temperature and [CO2] in the far future period of 2070–2099 for the wheat-growing region of Córdoba, Spain. The exposure of the wheat—Z. tritici pathosystem to elevated temperature reduced disease incidence compared with the baseline weather conditions, mainly affecting pathogen virulence, especially at the stages of host penetration and pycnidia formation and maturation. Interestingly, simultaneous exposure to elevated temperature and [CO2] slightly increased Z. tritici leaf tissue colonization compared with elevated temperature weather conditions, although this fungal growth did not occur in comparison with baseline conditions, suggesting that temperature was the main abiotic factor modulating the response of this pathosystem, in which elevated [CO2] slightly favored fungal development.

Formanilides from the culture broth of Perenniporia fraxinea.

A new formanilide dimer, fraxinin (1), and three known formanilides (2‒4) were isolated from the culture broth of Perenniporia fraxinea using silica gel and Sephadex LH-20 column chromatographies, medium-pressure liquid chromatography (MPLC), and preparative HPLC. The structures of these compounds were determined by spectroscopic methods, such as NMR and mass analysis, and by comparison of the spectra with previously reported data. The free radical scavenging activities of the isolated compounds were assessed using 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Compounds 1‒3 exhibited ABTS radical scavenging activity with IC50 values in the range of 57.2-250.2 μM. Compounds 2 and 4 marginally reduced disease incidence of powdery mildew with a control value of 42% at 1.0 mg ml-1 in cucumber leaf disk assay.

Analysis of Moko disease propagation on plantain (Musa AAB Simmonds) through a model based on system dynamics

Plantain represents one of the principal sources of income for Colombian farmers, besides being an important aspect of the national culture. Plantain is part of the daily diet for different social levels. Nevertheless, its production is threatened by diseases that have devastated entire crops and have forced many families to change their agricultural occupation. Moko (Ralstonia solanacearum phylotype II race 2) is one of the diseases that over time has caused considerable loses and continues to bring major phytosanitary problems to the region. The easy transmission of the pathogen makes it necessary to implement methodologies that help to limit the epidemic spread of the disease. In order to improve our understanding of the propagation of the disease through the plant’s developmental stages and contribute to establishing better targeted control measures, this paper proposes a population simulation mathematical model, which seeks to interpret the dynamics of Moko disease, bearing in mind the influence of the plant’s developmental cycle. We investigate the implementation of disease prevention on the population of susceptible and infected plants over time. The model has a good fit to the field data. The simulations, using the parameters estimated, showed that early elimination of infected plants is important to reduce disease incidence. It is also important to implement strategies to prevent the spread of the bacteria, which translates to a smaller probability of infection in any state.

Melatonin application suppresses oxidative stress and maintains fruit quality of cold stored ‘Esperanza’ raspberries by regulating antioxidant system

Raspberries are highly perishable and have a short storage life. To extend its storage life, we evaluated the impact of preharvest melatonin (MEL) application (0, 50, 100, 200 µmol L−1), three days before harvest, on the activities of oxidative and antioxidative enzymes and quality attributes in ‘Esperanza’ raspberries up to 10 d cold storage. The 200 µmol L−1 MEL-treated raspberries exhibited a significant reduction in disease incidence while maintaining higher marketable fruit and activities of superoxide dismutase, glutathione reductase, dehydroascorbate reductase, monodehydroascorbate reductase, ascorbate peroxidase and catalase as compared to control. Additionally, it reduced activities of polyphenol oxidase, peroxidase and lipoxygenase enzymes and increased flavonoids and ascorbic acid levels. However, preharvest spray of 100 µmol L−1 MEL mitigated fruit weight loss and maintained higher anthocyanins, and glutathione than control. In conclusion, MEL application (100–200 µmol L−1), three days before harvest, supressed oxidative stress by maintaining higher activities of antioxidant enzymes in raspberries during 10 d of cold storage.

Essential Oils and Antagonistic Microorganisms as Eco-Friendly Alternatives for Coffee Leaf Rust Control.

Coffee leaf rust (CLR) is caused by the biotrophic fungus Hemileia vastatrix Berk. & Br., a disease of economic importance, reducing coffee yield up to 60%. Currently, CLR epidemics have negatively impacted food security. Therefore, the objective of the present research study is to show a current framework of this disease and its effects on diverse areas, as well as the biological systems used for its control, mode of action, and effectiveness. The use of essential plant oils and antagonistic microorganisms to H. vastatrix are highlighted. Terpenes, terpenoids, and aromatic compounds are the main constituents of these oils, which alter the cell wall and membrane composition and modify the basic cell functions. Beneficial microorganisms inhibit urediniospore germination and reduce disease incidence and severity. The antagonistic microorganisms and essential oils of some aromatic plants have great potential in agriculture. These biological systems may have more than one mechanism of action, which reduces the possibility of the emergence of resistant strains of H. vastatrix.

Biosecurity: A holistic One-Health concept for enhancing the health, welfare, and productivity of commercial poultry - A point of view. Proceeding of The First International Avian Influenza Summit, University of Arkansas- October 16-17, 2023”

The poultry industry plays a pivotal role in meeting global demands for protein-rich food. However, it faces significant challenges due to emerging infectious diseases, environmental concerns, and ethical considerations surrounding animal welfare. This abstract presents a comprehensive perspective on the integration of biosecurity measures within the framework of One Health, with the aim of enhancing the overall health, welfare, and productivity of commercial poultry operations. The concept of One Health emphasizes the interconnectedness of human, animal, and environmental health. Applied to the poultry industry, this approach acknowledges the potential transmission of pathogens between animals, humans, and the environment, emphasizing the need for coordinated strategies. Biosecurity emerges as a central component, encompassing a multifaceted set of preventive measures designed to mitigate risks and safeguard the health of poultry populations. Key elements of an effective biosecurity program include physical barriers, hygiene protocols, vaccination strategies, and rigorous disease monitoring and surveillance. These measures are bolstered by the implementation of strict quarantine protocols for newly introduced birds, as well as restricted access to farms and controlled movements within the premises. Moreover, biosecurity extends beyond the farm gate, involving collaboration with veterinarians, government agencies, and industry stakeholders to establish best practices and response plans. Improving the welfare of commercial poultry is another critical aspect of this holistic approach. This involves providing optimal living conditions, access to clean water, balanced nutrition, and appropriate space allowances. Enrichment strategies, such as environmental enhancements and behavioral opportunities, contribute to the overall well-being of the birds, reducing stress and enhancing their natural behaviors. Furthermore, the integration of biosecurity and One Health principles positively impacts the productivity of commercial poultry operations. Reduced disease incidence leads to lower mortality rates and increased flock performance, translating to higher production efficiency. Additionally, improved welfare conditions contribute to reduced behavioral issues, resulting in better growth rates and feed conversion ratios. In conclusion, the adoption of biosecurity measures within the framework of One Health offers a comprehensive strategy for enhancing the health, welfare, and productivity of commercial poultry. This integrated approach not only mitigates the risks posed by emerging diseases but also addresses environmental and ethical concerns associated with poultry production. By embracing this holistic concept, stakeholders in the poultry industry can achieve sustainable and responsible production practices, ensuring the long-term viability of this crucial sector in global food security.

Biosynthesized silver nanoparticles enhanced wheat resistance to Bipolaris sorokiniana

Agronomic crops can benefit from the application of nanoscale materials in order to control phytopathogens and improve plant growth. Bipolaris sorokiniana, a soil- and seed-borne fungus, causes severe yield losses in wheat. In order to determine the physio-chemical changes in wheat under biotic stress of B. sorokiniana, the current study aimed to synthesis silver nanoparticles (AgNPs) using Allium sativum bulb extract. Herein, we applied the silver nanoparticles (AgNPs) as a foliar spray on two wheat varieties (Pakistan–2013, and NARC–2011) at the concentrations of 10, 20, 30, and 40 mg/L to suppress B. sorokiniana. Among all the applied concentrations of AgNPs, the 40 mg/L concentration demonstrated the most effective outcome in reduction of the intensity of spot blotch and improved the morphological, physiological, biochemical parameters, as well as antioxidant activity in wheat plant. Foliar application of AgNPs at 40 mg/L Pakistan-2013 and NARC-2011 wheat varieties significantly increased chlorophyll a 84.8% and 53.4%, chlorophyll b 28.9% and 84.3%, total chlorophyll content 294.3% and 241.2%, membrane stability index 7.5% and 6.1%, relative water contents 25.4% and 10.5%, proline content 320.5% and 609.9%, and soluble sugar content 120% and 259.4%, respectively, compared to control and diseased plant. This is the first study provides important insights into the role of phyto-mediated AgNPs in increasing resistant of wheat infected with B. sorokiniana. These findings offers valuable new insights that may be useful for reducing disease incidence in wheat fields.

Exploring the impact of cyclic lipopeptides from <i>Bacillus subtilis</i> NBAIR-BSWG1 through <i>in vitro</i> and <i>in planta</i>, studies against <i>Sclerotium rolfsii</i>

Bacillus subtilis is a Gram-positive bacterium known for its antagonistic attributes, particularly through the production of various secondary metabolites, including lipopeptides. In this study, we investigated the antagonistic capabilities of B. subtilis strain NBAIR-BSWG1 with a focus on assessing the efficacy of NBAIR-BSWG1 in combatting Sclerotium rolfsii. Our findings demonstrated substantial inhibitory effects, with 82.73% to 100% reduction in S. rolfsii growth when exposed to NBAIR-BSWG1 at concentrations ranging from 50 to 100 µL/mL in poison food technique. In dual culture assay, NBAIR-BSWG1 exhibited a significant 55.50% inhibition of S. rolfsii. Moreover, pot experiments revealed a promising 26% reduction in disease incidence. This study underscores the significant role of NBAIR-BSWG1 in controlling S. rolfsii, holding substantial potential for developing effective formulations aimed at mitigating the southern blight of tomatoes.

Evaluation of Biocontrol Potential of Bacillus spp. and Pseudomonas fluorescens UM270 against Postharvest Fungal Pathogens

Fungal pathogens are the main causal agents of postharvest diseases of fruits and vegetables. To prevent this problem and avoid the use of harmful chemical fungicides, safer and greener alternatives have been sought. One of these alternatives is the use of plant-growth-promoting bacteria (PGPB). In this study, we evaluated in vitro four well-known PGPB strains (Pseudomonas fluorescens UM270, Bacillus toyonensis COPE52, Bacillus sp. E25, and Bacillus thuringiensis CR71) for their biocontrol potential against nineteen postharvest fungal pathogens. In vivo assays were also performed, and bacterial cells were inoculated on harvested strawberries and grapes with the pathogens Botrytis cinerea, Alternaria alternata, and Fusarium brachygibbosum to evaluate loss of firmness and disease incidence. Our results show that the four strains antagonized fungi in direct and indirect confrontation assays. Stronger antagonism was observed by the action of diffusible metabolites (DMs) compared to volatile organic compound (VOC) activity. All PGPB significantly improved the fruit firmness and reduced disease incidence caused by the fungal pathogens tested. However, strain UM270 showed excellent biocontrol activity, reducing the disease incidence of Fusarium brachygibbosum, Botrytis cinerea, and Alternaria alternata on strawberry fruits by 60%, 55%, and 65%, respectively. Diffusible antifungals and VOCs such as 2,4-diacetyl phloroglucinol, siderophores, auxins, fengycins, and N, N-dimethyl-hexadecyl amine, among others, might be responsible for the beneficial activities observed. These results suggest excellent biocontrol activities to inhibit postharvest pathogenic fungi and improve harvested fruit quality.

Integrated Approach to Management of Brown Root Rot Disease of Tea (Camellia sinensis (L)O.Kuntze).

Abstract: Brown root rot disease caused by Fomes lamoensis and Trott has been identified as the primary root disease of tea. Indiscriminate use of chemicals in tea garden area has an adverse effect on the environment. For management of this root disease, integrated approach is required for sustainability in tea cultivation. The present study involves the use of five systemic fungicides, which were screened and tested against the pathogen. Total five fungicides used, among the fungicides propiconazole and hexaconazole was inhibit 98.51% and 100% growth of pathogen @ 100mg/l concentration. However bavistin, roko and ektino, showed in12.58%, 5.18% and1.48% inhibition respectively. Bacillus cereus and Trichoderma harzianum were also evaluated and efficiently inhibited F. lamoensis in vitro. The zone of inhibition varied from 10 to 15 mm in case of B. cereus and 10 to 16 mm in case of T. harzianum. The nursery experiment exhibited that tea plants at 120 days after the treatment (DAT) with the pathogen showed 76.66% disease incidence. The reduction in disease incidence (23.33% and 13.25% respectively) was observed when the plants were treated with biocontrol agents i.e.B. cereus and T. harzianum. In case of chemically treated plants only 10% disease incidence was observed. The results of the nursery experiment showed that both the chemicals and biocontrol agents significantly affected incidence of disease and promoted growth of tea measured in terms of shoot height, root length, number of new leaves, lateral branches, biomass of shoot and root over the control.

Biocontrol Efficacy of Metschnikowia spp. Yeasts in Organic Vineyards against Major Airborne Diseases of Table Grapes in the Field and in Postharvest.

The aim of this work was to evaluate the efficacy of two antagonistic yeasts, Metschnikowia pulcherrima strain MPR3 and M. fructicola strain NRRL Y-27328 (commercial product NOLI), applied in addition to the "on-farm biological treatments" (BIO) carried out during the production season, for the containment of powdery mildew and grey mould diseases on organic table grapes 'Italia'. The yeast strains were applied in the field three times, and their efficacy was evaluated during the production season and under postharvest conditions. Overall, M. pulcherrima MPR3 combined with BIO treatments reduced disease incidence caused by Erysiphe necator and disease incidence and severity caused by Botrytis cinerea with values between 67.8% and 86.2%, showing higher efficacy than BIO treatments applied alone and in combination with NOLI. Field treatments based on BIO+MPR3 maintained their performance also during fruit storage, protecting grape berries from grey mould development to a greater extent than the other treatments (disease reduction of about 98%). Thus, the presence of M. pulcherrima MPR3 seems to improve disease management both in the field and in postharvest environments, without negative impacts on grape microbial communities. These findings highlight the potential of M. pulcherrima MPR3 as a promising alternative strategy for disease control in organic vineyards and in postharvest, providing sustainable solutions to improve food quality and safety.

Enhancement of soil suppressive potential to bacterial wilt disease caused by Ralstonia solanacearum

The effect of wheat and maize rotations and the application of plant-animal compost on potato bacterial wilt and yield was investigated. The proposed method was tested in three separate locations, each two acres in size, with an untreated control. The first two were naturally infested, but the third was pathogen-free. Infested locations that had been treated experienced a significant reduction in disease incidence. The addition of a bio-fertilizer mixture (Azotobacter sp., Azospirillum sp., Bacillus megaterium, and Bacillus circulans) improved the compost’s suppressive potential. The method increased soil organic matter (SOM), N, P, K, Ca+2, and Mg+2 while decreasing Na+ levels and increasing potato yield. The relative abundance of Ralstonia decreased while that of Arthrobacter, Streptomyces, and Nocardioides increased. The presence of Gracilibacillus, Cellvibrio, Bacillus, and Paenibacillus was associated with a decrease in Ralstonia, whereas the presence of Propionibacterium (a nitrogen-fixing bacteria) was associated with an increase in Ralstonia.