1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Diversity of sclerotium rolfsii infecting yams(Department of plant pathology,College of Agriculture,Vellayani, 2025) Neha Anil; Heera GThe study entitled “Diversity of Sclerotium rolfsii infecting yams” was conducted at Department of Plant Pathology, College of Agriculture, Vellayani during 2023-2025 with the objectives of cultural, morphological, and molecular characterization; assessment of cross infectivity and genetic variability of Sclerotium rolfsii infecting yams. A survey was conducted in six Agro-Ecological Units (AEUs) of Kerala comprising of districts viz.,Thiruvananthapuram (Vellanad, Aruvikkara, Nedumangad and Neyyatinkkara), Kollam (Kochanjilmoodu and Kottarakara), Alappuzha (Tamarakulam and Cherthala), Kozhikode (Orkkateri, Vadakara, Aroor, Chekkiad, Vattoli and Vattoli North) and Kannur (Chonadam and Thalassery). A total 32 diseased samples were collected from different yams viz Elephant foot yam (EFY), Colocasia, and Dioscorea from 16 distinct locations of the surveyed areas. Of the 32 isolates obtained 25 isolates were collected from EFY, four isolates from Colocasia, and three isolates from Dioscorea. Disease incidence (DI) in the surveyed areas showed a range between10.0% to 60.0%. The pathogenicity tests confirmed virulence of the pathogen, with symptoms manifesting between 3 to 6 days post- inoculation. EFY plants inoculated with the isolates toppled within 12-20 days, whereas Colocasia and Dioscorea plants failed to topple. Isolates IA17 (EFY) collected from Orkatteri (AEU10), IC4 (Colocasia) collected from Chonadam (AEU2) and ID3 (Dioscorea) collected from Cherthala (AEU1), were identified as the most virulent isolates, inducing symptoms within 3-4 days on their original host. Cultural and morphological characterization revealed significant diversity. Mycelial growth rate varied from 1.53 cm/day to 2.46 cm/day. The isolate IA13 with growth rate of 2.46cm/day was identified as fast grower. The fungal isolates exhibited rapid mycelial growth, completing full growth in petri plate(9cm) in 3-5 days, displaying colors ranging from white, pure white, to dull white without any pigmentation. Colony texture varied, from fan-like to thick-centered (IA3, IA7), fluffy (IA8, IA14), and compact (ID2), with regular margins (except IA3, IA7). Days for sclerotial initiation was between 7-14 days while isolates IA15 and ID2 did not produce sclerotia. Sclerotia were smooth, round, light cream to light/dark brown. Meanwhile after two weeks of sclerotial initiation the number of sclerotia ranged between 25 (IC1) to 211 (IA10). The weight of 100 sclerotia varied from 56mg (IC1) to 195mg (IA3), and their size from 0.90 mm (IA12) to 1.99 mm (IC2). Microscopic analysis confirmed the presence of clamp connections, with septal distance ranging from 20.90μm (IA20) to 136.29μm (IA7), and hyphal width from 1.30μm (IA18) to 6.23μm (IA7). The most virulent isolates (IA17, IC1, and ID2) were identified as Agroathelia/Athelia rolfsii (Teleomorph of S. rolfsii) through molecular characterization, using ITS primers and the sequences were submitted to GenBank. Cross-infectivity studies confirmed that all 32 isolates were capable of infecting all three yam host. The symptom development was delayed in cross- inoculated hosts (7–11 days) compared to the original host (3–6 days). Despite the absence of plant toppling symptoms, Colocasia and Dioscorea plants cross-inoculated with isolates (IA1 to IA25) showed more sclerotia with sparse mycelial growth, when compared to the symptoms of original host infection. Lesion sizes ranged from 10 cm2(ID1 x A) to 27.99 cm2 (IC4 x A) on Elephant Foot Yam (EFY), 8 cm2 (IA18 x C) to 32 cm2 (IA22 x C) on Colocasia, and 8 cm2 (IA8 x D) to a maximum of 42 cm2 (IA17 x D) on Dioscorea plants. Genetic diversity analysis using five SSR primers generated 182 scorable bands with polymorphism indicated substantial genotypic heterogeneity. Primers MB-14 and BJ112 exhibited the highest Polymorphism Information Content (PIC value of 0.5). Jaccard's similarity coefficient ranged from 0.00 to 1.00. Critically, pairs of isolates were identified as clones (e.g., IA18/IA19, IC2/IC4) with similarity index of 1.00. At a Jaccard similarity coefficient (JC) of 0.82, the fungal isolates resolved into three major phylogenetic clusters. One distinct cluster was formed by the isolates IA20 (AEU9) and IA21 (AEU9), indicating a high degree of genetic similarity between these two specific isolates. The 16 isolates of EFY formed the second, separate, and larger cluster. The remaining EFY isolates formed a third cluster with colcoasia and dioscorea isolates. Cluster analysis of this cluster indicated significant genotypic overlap between isolates from Elephant foot yam, Colocasia, and Dioscorea, suggesting successful, shared genotypes across different hosts, alongside the presence of highly dissimilar specialized genotypes. This comprehensive analysis confirms genetic diversity in the pathogenic S. rolfsii population infecting yams across Kerala. Virulence assessment were confirmed by the detection of oxalic acid in the most virulent (IA17, IC4, and ID3) and lesser virulent (IA7, IC1, and ID1) isolates from High-Performance Liquid Chromatography (HPLC) analysis. The study confirmed that oxalic acid (Retention Time 3.2 min), is a key necrotrophic effector, in the culture filtrates of the S. rolfsii (7DAI) isolates from EFY, Colacasia and Dioscorea. Analysis of peak areas revealed a direct correlation between fungal virulence and the production of Oxalic acid. IA17, IC4 and ID3 were identified as the most virulent ones in pathogenicity assays as these isolates exhibited the highest oxalic acid content. Conversely, a lower content of oxalic acid was observed in the IA7, IC1, and ID1 isolates with less virulence. The present study demonstrated that S. rolfsii infecting yam species in Kerala is characterized by high levels of pathogenic, morphological, and genetic diversity.The cross infectivity studies showed polyphagous nature of S. rolfsii affecting yams. The isolates from different yams were clustered into three different clusters indicating variability. The demonstration of broad cross-infectivity and the detection of shared, highly successful genotypes across different hosts necessitates the implementation of integrated disease management strategiesItem Schizophyllum commune for the management of colletotrichum leaf blight of turmeric.(Department of Plant Pathology, College of Agriculture, vellayani, 2025) Gibence, H Rose Winnie; Heera, GThe study entitled “Schizophyllum commune for the management of Colletotrichum leaf blight of turmeric’’ was carried out at College of Agriculture, Vellayani during 2021-2023, with the objective of characterization and utilization of antimicrobial compounds from S. commune for the management of Colletotrichum leaf blight of turmeric. Survey was conducted during October 2022-February 2023 in three districts of Kerala, viz., Thiruvananthapuram, Kollam and Alappuzha to study about the disease incidence (DI) and disease severity (PDI) of leaf blight of turmeric. The disease incidence ranged between 31.12 – 55.11% and disease severity between 24.32 – 62.00 %. The highest DI and PDI was observed at Neyyattinkara location of Thiruvananthapuram. The common symptom observed in surveyed area was brownish necrotic blighting from tip or margin with prominent yellow halo. Ten fungal isolates were obtained, sub-cultured and purified. Pathogenicity of these fungal isolates were proved. The pathogen was identified as Colletotrichum sp. The morphological studies of Colletotrichum sp. revealed that mycelial width, septal distance and conidial size ranged from 1.01- 1.85 µm, 13.41-7.98 µm and 9.10 × 3.70 - 18.54 × 4.50 µm2 respectively. The conidial shape was either dumbbell or oblong. Colony colour was either off white, ash grey or dark grey. Colletotrichum isolate C6 was identified as the most virulent (Sadanandapuram from Thiruvanathapuram) after virulence rating. The molecular characterization of isolate C6 was done using ITS primers where it had the maximum identity with Colletotrichum gloeosporioides. Morphological, cultural and molecular characterization is done and identified C6 isolate as C. gloeosporioides. The mycelial growth of Schizophyllum commune was either fluffy, cottony or sparse. The mycelial growth rate was maximum in SC5 (S. commune 5; DMRX-2160) followed by SC3 (S. commune 3; DMRX-2158) (1.03 and 1.01 cm day-1 respectively). SC 1 (S. commune 1; DMRX-2156), SC2 (S. commune 2; DMRX-2157), SC4 (S. commune 4; DMRX-2159) exhibited growth rate of 0.92, 0.81 and 0.69 cm day-1 respectively. Potato dextrose agar (PDA) was identified as the most suited and Czapek dox agar (CDA) least suited media for S. commune. In vitro antagonism was done by dual culture assay and poisoned food technique. All the S. commune strains were effective in managing the pathogen in vitro. The strains SC1, SC3, and SC5 exhibited lysis where as SC2 and SC4 showed overgrowth as mode of inhibition in dual culture assay. Highest inhibition was exhibited by SC5 (40.78 %) followed by SC3 (39.62%). Different concentration viz., 25, 50 and 75% of S. commune culture filtrate were tested against C. gloeosporioides in poisoned food technique. Among these, 75% concentration exhibited highest inhibition percentage. SC5 culture filtrate amended media showed highest inhibition (44.46%) of followed by SC3 (37.03%). Two most effective strains of S. commune viz., SC5 and SC3 were selected for in vivo studies. In vivo studies were conducted to evaluate effect of S. commune mycelial extract and cell free culture filtrate (CF) on leaf blight of turmeric in comparison with biocontrol agent (Pseudomonas fluorescens) and chemical control (Propiconazole). Among all the treatments spraying culture filtrate of SC5 at seven days interval showed lowest PDI (17.76%) at 14 days after inoculation (DAI) followed by propiconazole (T8), P. fluorescens (T7) and culture filtrate of SC5 (T5) which were statistically on par with each other. Similar trend was also observed at 21 and 28 DAI. Similarly, lowest lesion size observed in T5 (CF of SC5) at 14 DAI (1.96 ×1.4 cm2), 21 DAI (2.4×1.6cm2) and 28 DAI (3.96×2.3cm2). The maximum plant height was observed in T7 (127.66 cm) followed by absolute control (126.65 cm) and T5 (125 cm). There was no significant difference in the number of leaves in response to different treatments. Plant defence enzyme viz., peroxidase, polyphenol oxidase, and phenyl alanine ammonia lyase showed enhanced activity followed post inoculation the spray of P. fluorescens and culture filtrate of SC 5. Hot water extraction recovered 0.18g and 0.119g crude polysaccharide from S. commune mushroom mycelial powder and culture filtrate respectively. The results of this study revealed wide spread occurrence of Colletotrichum leaf blight in the turmeric growing areas of Kerala viz., Thiruvananthapuram, Kollam and Alappuzha. Wide variation in cultural and morphological characters of Colletotrichum isolates was observed from the surveyed areas. The most virulent isolate (C6) obtained from Sadanandapuram identified as Colletotrichum gloeosporioides based on cultural, morphological and molecular characters. PDA was identified as the most suitable media for the growth of S. commune. Schizophyllum commune strains possessed biocontrol potential with lysis and overgrowth as mode of action against C. gloeosporioides in dual culture assay. Culture filtrate of S. commune reduced the disease severity in leaf blight of turmeric. Crude polysaccharides were present in culture filtrate as well as in mushroom mycelial powder. The active compound responsible for biocontrol property of S. commune should be identified, fractionated and structurally elucidated. In vitro and in vivo activity of purified compound against fungal, bacterial and viral pathogens should be investigated and more research is needed for field level application.Item Exploring the biocontrol efficacy of native isolates of Trichoderma spp. of Kasaragod district(Department of Plant Pathology, College of Agriculture,Padannakkad, 2025) Kamsali Achyuth Achari.The study entitled “Exploring the biocontrol efficacy of native isolates of Trichoderma spp. of Kasaragod district” was carried out in the Department of Plant Pathology, College of Agriculture, Padannakkad during 2022-2024 with the objective of evaluation of selected native Trichoderma spp. of Kasaragod district for abiotic stress tolerance, plant growth promotion and biocontrol efficiency against damping off of brinjal. The evaluation of temperature tolerance of Trichoderma spp. revealed that the strains, Tr-5, Tr-12, Tr-41, Tr-43, KAU (T. asperellum), and Tr-40 (T. lixii) did not exhibit any mycelial growth or sporulation at 4°C, 10°C, 45°C and 55°C. At 15°C, the strain, Tr-40 showed the highest radial growth (0.85 cm), followed by Tr-41 (0.66 cm), while the KAU reference culture recorded the least growth (0.26 cm). All the strains demonstrated robust mycelial growth at the optimum temperature (30°C), almost on par with the control. In drought and salinity tolerance assays, the strains displayed good mycelial growth and effective sporulation at 10 per cent polyethylene glycol (PEG) and 0.5 M NaCl concentration. However, at higher PEG levels (30% and 40%), radial growth was markedly reduced, and colonies exhibited irregular margins and a light fluffy texture, indicating stress. At 1.5 M NaCl concentration, the strains, Tr-5 (0.83 cm), Tr-12 (0.9 cm), and Tr-40 (0.8 cm) sustained mycelial growth with a light fluffy texture. None of the strains exhibited growth at 2.5 M NaCl. Compatibility of the strains of Trichoderma spp. with other biocontrol agents viz., Pseudomonas fluorescens, Metarhizium anisopliae, Lecanicillium lecanii, and Beauveria bassiana was assessed by the dual culture technique. The highest percentage compatibility (99.3%) was expressed by Tr-5 and Tr-12, followed by Tr-41 and Tr-43 (98.5%) with P. fluorescens. Regarding compatibility with fungal biocontrol agents, all the native strains of Trichoderma spp. and KAU culture showed good compatibility with B. bassiana, M. anisopliae and L. lecanii. But, the strain Tr-40 showed high per cent inhibition and less compatibility percentage with M. anisopliae (66.7%) and L. lecanii (33.58%). The root colonization of Trichoderma spp. on brinjal seedlings was visualised under a Zeiss compound microscope (400x, Axiocam 105 camera) at 15 DAS (days after sowing) under in vitro conditions. The presence of mycelia of these Trichoderma strains was observed on the surface of the roots of the brinjal seedlings. The effect of Trichoderma strains on plant growth was assessed using the paper towel method. The highest germination percentage was recorded in Tr-5 (83%) and Tr-41 (73%), and the least was in Tr-40 with 53%. The height of the seedlings (shoot + root length) was recorded as the highest in the Tr-5 (12.86 cm), followed by control (12.27 cm). Compared to other treatments, the Tr-5-treated seedlings showed good fresh weight (119.33mg), dry weight (20.66mg), and also vigour index (1072.66). Biocontrol efficacy of different strains of Trichoderma spp. in managing the damping off in brinjal was studied. In the seed application alone treatment (a1), germination of seeds was observed 3 DAS in treatments, a1t1, a1t2, a1t3, a1t5 and a1t9; and was 5 DAS in the control (t8). The highest germination percentage was observed in a1t3 (36.33%) and the lowest in t8 (13.33%). Here, the plants in control recorded the highest per cent disease incidence of 66.6% and in the case of a1t4 it was only 10 per cent. In the soil application alone treatments (a2), the germination of seeds was observed within 3 to 4 DAS, except the control (t8), where it was 5 DAS. Among all the treatments, the highest germination percentage was recorded in absolute control (59.9%) followed by treatments, a2t1, a2t2, a2t4, with 53.33 per cent. No disease incidence was recorded in a2t4. In the seed and soil combined application (a3), the highest germination percentage recorded was 66.67 in a3t1, in which no infected seedling was observed. The combined application of Trichoderma spp. showed a significant effect on the plant growth and the disease. The expression of defense-related genes in brinjal seedlings when exposed to Fusarium sp. was notably increased in the presence of T. asperellum strain Tr-5. There was a 3.47-fold increase in the expression of the PR-3 gene which codes for chitinase. This marked upregulation of the PR-3 gene highlights its role in enhancing defense responses and suppressing the pathogenItem Integrated management of fruit rot of jackfruit incited by Athelia rolfsii(Department of Plant Pathology, College of Agriculture, Vellayani, 2024-02-03) Gurubilli Divya SriThe study entitled ‘Integrated management of fruit rot of jackfruit incited by Athelia rolfsii’ was conducted during 2021-23 at College of Agriculture, Vellayani and IFSRS, Karamana with an objective to assess the factors influencing growth of A. rolfsii and development of an integrated disease management strategy against fruit rot of jackfruit. A survey was conducted in four agro-ecological units of Kerala viz., AEU 4, 8, 9 and 14 covering Thiruvananthapuram, Alappuzha, Pathanamthitta, Kollam and Kottayam districts. Fruit rot affected jack fruit samples were collected from a total of eight locations i.e., 2 from each AEU during 2021-23. Six out of the eight fruit rot affected fruit samples were observed at soil level whereas the remaining two were above soil level. The disease was manifested as white, fan shaped mycelial growth with presence of cream coloured sclerotia on fruits. Gradually, discolouration and rotting were observed on the fruits. The natural incidence of the disease was observed at slightly acidic to neutral pH, at soil temperature of 24 to 34℃ and 21 to 50.40 per cent soil moisture level. Pathogen isolation was undertaken from each fruit rot affected jack fruit sample collected from the eight locations and pathogenicity of the isolates was confirmed individually. The mycelia of all the isolates appeared as white with fan shaped growth except for a cottony appearance in the case of Kunnumma isolate. All the isolates produced round shaped sclerotia with colour variations ranging from light cream to dark brown. Among all the isolates, Karamana isolate took the least days for completion of mycelial growth (3 days) and formation of sclerotia (5 days) in vitro. The pattern of growth of sclerotia appeared as scattered (Venganoor, Chavara, Alappuzha, Kunnumma and Pathanamthitta isolates), ring like at centre (Karamana and Koodal isolates) and aggregated at the centre (Kottayam isolate). The hyphae of all the isolates were septate with size ranging from 0.02 to 0.03 μm. The size of the sclerotia of the isolates ranged from 1.02 to 2.00 mm. Karamana isolate was revealed to be the most virulent isolate with 195.84 cm2 of infection area within three days of artificial inoculation on fruits. The virulent isolate of the pathogen was selected for identification. Morphological and cultural characters including presence of fan shaped mycelia and clamp connections confirmed it as A. rolfsii. Further, molecular characterization using ITS primers conclusively confirmed the fungus as A. rolfsii. Evaluation of chemicals for their antifungal potential against A. rolfsii by poisoned food technique revealed that dithane M-45 75% WP, tebuconazole 25% WG, propineb 70% WP and hexaconazole 5% EC completely inhibited the fungus at recommended and half the recommended dose. The chemicals viz., dithane M-45 75% WP, tebuconazole 25% WG and hexaconazole 5% EC were effective even at one fourth of the recommended dose. In vitro evaluation of biocontrol agents by dual culture technique revealed that Trichoderma asperellum (KAUT6) and Trichoderma viride (NBAIR) were the most effective bio agents which resulted in 80.55 and 51.77 per cent inhibition of the mycelial growth of the fungus respectively. Studies on the compatibility between effective chemicals and biocontrol agents revealed that T. asperellum (KAUT6) was completely compatible with hexaconazole 5% EC (0.025%, 0.05%, 0.1%) and dithane M-45 75% WP at recommended dose, half as well as quarter of the recommended dose. Tebuconazole 25% WG showed compatibility with T. asperellum (KAUT6) at quarter of its recommended dose only. In vitro assessment of the influence of various environmental factors on the growth of the fungus on artificially inoculated fruits was conducted. Exposure to varying light intensities revealed that alternate cycles of light and darkness promoted mycelial growth of A. rolfsii compared to continuous darkness and other varying levels of light intensity. Evaluation of influence of different levels of temperature demonstrated that high temperature levels of 37 and 40˚C inhibited the growth of the fungus when artificially inoculated on to the fruits. The pH range for optimum growth of mycelium and production of sclerotia was revealed to be within a range of 5.5 to 6.5. High soil moisture percentage was revealed to inhibit the growth of the fungus. Pre and post application of the best effective contact fungicide, bio agent and their combination on artificially inoculated jack fruits revealed that pre application of dithane M- 45% WP (0.3%) resulted in complete (100%) inhibition of the growth of the fungus on fruits upto one week period wherein the untreated inoculated fruit got completely rotten. Studies on post-application of dithane M-45% WP (0.3%) at 24 h after artificial inoculation resulted in complete (100%) inhibition of the growth of the fungus followed by post application of talc based formulation of T. asperellum (KAUT6). However, subsequent observations revealed that, beyond 72 hours after artificial inoculation, the virulent isolate of the fungus continued to grow on the fruits, revealing that neither the chemicals nor the biocontrol agents, alone or in combination, was effective in controlling the fungus on artificially inoculated fruits. Thus, the present study could identify A. rolfsii as a predominant fungal pathogen causing fruit rot of jackfruit in Kerala. The disease incidence was revealed to be influenced by the prevailing weather conditions. It was revealed that pre application of dithane M-45 75% WP (0.3%) before artificial inoculation as well as post-application of dithane M-45 75% WP (0.3%) within 72 hours of artificial inoculation were the most effective treatments followed by dithane M-45 75% WP (0.3%) combined with talc based formulation of T. asperellum (KAUT6). Further validation through multi-seasonal field trials need to be undertaken to identify the cardinal environmental factors resulting in disease incidence as well as to develop a holistic approach for the integrated management of the disease.Item Tablet formulation of plant growth promoting microbes (PGPM) for the management of foot rot of black pepper(Department of Plant Pathology, College of Agriculture, Vellanikkara, 2025) Hiba Abdurahiman, U.Plant pathogens and pests pose significant challenges to agricultural productivity. While synthetic agrochemicals provide rapid and reliable solutions, their excessive use has led to environmental and health concerns, driving the search for more sustainable alternatives. Biological control, an eco-friendly and cost-effective strategy, employs beneficial organisms such as plant growth promoting microbes (PGPM) to combat plant pathogens through diverse mechanisms. However, conventional formulations of biocontrol agents, including talc and liquidbased products, have limitations such as short shelf life, bulkiness, transportation difficulties, and contamination risks. Thus, the current study entitled ‘Tablet formulation of plant growth promoting microbes (PGPM) for the management of foot rot of black pepper’ is undertaken during the period from 2022-24 at Department of Plant Pathology, College of Agriculture, Vellanikkara to develop tablet formulation of plant growth promoting microbes (PGPM) and evaluate its biocontrol efficacy under in vivo conditions. The PGPM used in this study included Bacillus cereus (BPB 16) as the bacterial isolate and Trichoderma asperellum (BPT 8) and Trichoderma harzianum (CT 30) as the fungal isolates. These were characterized through cultural, morphological, and molecular methods. Media optimization was carried out by culturing the isolates in basal media - Nutrient Broth (NB) for bacteria and Potato Dextrose Broth (PDB) for fungi, supplemented with additives such as sugar sources [mannitol, trehalose], wetting agents [polyvinyl pyrrolidone (PVP), poly ethylene glycol (PEG)], adhesives [glycerol, carboxy methyl cellulose (CMC)], and surfactant (tween-80). Nine treatment combinations were tested, with population density recorded from 15 days after inoculation (DAI) to six months after inoculation (6 MAI). The treatments T4 (NB + mannitol, PEG, CMC, Tween-80) for Bacillus cereus, T3 (PDB + mannitol, PEG, glycerol, Tween-80) for Trichoderma asperellum, and T6 (PDB + trehalose, PEG, glycerol, Tween-80) for Trichoderma harzianum demonstrated the most stable population densities over six months varying from 24.67 x 1012to 18 x 108cfu ml-1, 11 x 1012 to 9.67 x 108cfu ml-1 and 40.50 x 1012 to 11.33 x 108cfu ml-1respectively. The best additive combinations for each microbe were selected for preparation of tablet formulation of PGPM. The carrier material used for preparation of tablet was talc and these tablet formulations were optimized by adjusting the carrier material's moisture content to 5 per cent and 8 per cent. Stability tests revealed that 5 per cent moisture tablets stored under refrigerated conditions had the highest population density (15.50 × 10⁸ cfu ml⁻¹), followed by those stored at ambient conditions (12.33 × 10⁸ cfu ml⁻¹) after three months of storage (3 MAS). While standardizing the recommended dosage of the formulation, it was noticed that one tablet dissolved in 100 litres of water produced population densities of 7 × 10⁶ cfu ml⁻¹ and 4 × 10⁶ cfu ml⁻¹ for 5 per cent and 8 per cent moisture tablets, respectively. The biocontrol efficacy and plant growth promotion of the PGPM tablets were assessed in a pot culture experiment against Phytophthora sp. causing foot rot disease in black pepper variety, Panniyur-1. Tablet formulations of PGPM, conventional liquid and talc formulations of Pseudomonas and Trichoderma, talc formulation of PGPM, copper oxychloride as chemical check and an absolute control were the treatments laid out in the experiment. The polybags were challenge inoculated with the pathogen after 15 days of first treatment application and on symptom appearance, treatments were applied thrice as soil and foliar application at 10 days interval. Plant growth parameters such as height, number of leaves, number of nodes of black pepper cuttings as well as disease incidence, and severity were recorded. On analysis of the biometric parameters, it was noticed that plants treated with PGPM tablet formulations exhibited the highest plant height, number of nodes and leaves and was comparable with the talc based formulation of PGPM. Likewise, observations on disease incidence and severity revealed that the tablet formulation of PGPM was superior among all treatments followed by the liquid formulation of Trichoderma and these results were comparable to the chemical check, copper oxy chloride (0.25 %). Observations on enumeration of viable count of fungi, bacteria and actinomycetes in the soil were recorded before and after treatment application by serial dilution and plating technique and it was noticed that the tablet formulation of PGPM consistently showed the highest soil microbial count. It was further noticed that the bacterial population was comparatively higher in all treatments compared to the population of fungi and actinomycetes. The study has successfully developed and standardized a protocol for producing tablet formulation of plant growth promoting microbes (PGPM) that exhibit both stability and efficacy. These tablets demonstrated the ability to retain high microbial population densities under refrigerated and ambient storage conditions for a minimum period of three months. Furthermore, the formulation has been optimized to be user-friendly, with a recommended application rate of one gram dissolved in 100 liters of water, ensuring an effective microbial concentration for practical use. To ensure wider applicability and adoption, multi-locational field trials should be conducted in different crops against various diseases to validate the findings and once validated, the PGPM tablet formulation holds the potential for commercialization as a sustainable biocontrol solution, offering farmers an ecofriendly alternative to chemical pesticides for managing plant diseases and promoting crop health.Item Termitomyces species of central and northern Kerala(Department of Plant Pathology, College of Agriculture,Vellanikkara, 2025) Pooja, A S.; Gleena Mary, C FTermitophilous fungi, commonly known as termite mushrooms, are monophyletic group of gilled mushrooms which belong to the genus Termitomyces of the family, Lyophyllaceae under Basidiomycota. These mushrooms are native to tropical and subtropical regions of Africa and South-east Asia and exist exclusively in symbiosis with termites of the sub-family Macrotermitinae in their natural habitats. The warm humid tropical climate along with the diverse soil types of Kerala, support the luxuriant growth of various termite mushroom species throughout the monsoon season. Although several research on this mushroom have been conducted, many of them concentrated mainly on the morphological characters and proximate analysis of the available species. In light of this, the current study, entitled “Termitomyces species of Central and Northern Kerala” was undertaken to document the habitat, distribution, and species diversity of termite mushrooms across Central and Northern Kerala and to compare the nutritive value of different edible species. A purposive sampling survey was conducted across the Central and Northern regions of Kerala, including the districts of Thrissur (AEU 02, 06, 10), Kasaragod (AEU 07, 11), and Wayanad (AEU 20, 21), to collect the fresh basidiocarps of Termitomyces species during the North-East and South-West monsoon seasons (October 2023 - October 2024). Among the seven AEUs selected, 10 locations were surveyed, and 28 samples were collected and subjected to morphological and molecular characterization. Out of the 28 Termitomyces samples collected, 20 samples were from Thrissur district, six from Wayanad district and two samples were obtained from Kasaragod district. Of the collected samples, T. microcarpus (T1, T2, T8, T20, W5, W6, K1, K2), was the most widely distributed species which typically appeared in groups of 15 - 60 fruiting bodies under mixed vegetation. The next most prevalent species were T. srilankensis (T13, T14, T15, W4), appeared as solitary fruiting body and T. heimii (T18) observed in groups of 6 to 70 sporocarps in humus-rich soils of Thrissur district over a continuous three-week period in the month of September 2024. The sample, W6 collected from Wayanad district was found to appear periodically in the same location thrice in the surveyed period. Based on morphological characteristics of the pileus, perforatorium, stipe, annulus and pseudorhiza, nine species were identified to species level, which include T. eurrhizus, T. srilankensis, T. fuliginosus, T. microcarpus, T. heimii, T. striatus, T. schimperi, T. clypeatus, and T. robustus. The macroscopic observations such as size of the pileus (diameter) in observed samples of Termitomyces varied from 0.7 cm (T. microcarpus) to 15.4 cm (T. srilankensis) and colour varied between white, light brown to dark brown. The perforatorium was varied in its shape from umbonate, conical to spiny form with the colour variation from light brown to dark brown. The lamellae were adnate to adnexed and freely arranged (T. microcarpus), to compact arrangement in all the other species and its colour varied from yellowish (T. microcarpus) to light brown and whitish. The stipe colour varied from whitish to greyish or brown, depending on the species and measured 1.8-3.8 cm in length and 0.2-0.3 cm in diameter in T. microcarpus, whereas larger species like T. eurrhizus, T. srilankensis, T. fuliginosus, T. heimii, T.schimperi, T. clypeatus, T. striatus, and T. robustus showed stipe size of 14.5- 15.2 cm x 2.3-10.6 cm. Annulus was present only in T. schimperi and T. heimii. Pseudorhiza was observed in all the species with varying size and nature but was absent in T.microcarpus. The micro-morphological characters like, size and shape of basidia, pleurocystidia and cheilocystidia, along with basidiospores and type of pileipellis layer were studied. Among the 28 samples, six samples had cutis form of pileipellis layer, 20 samples with ixocutis form, and two samples showed ixotrichodermium form. The shape of the basidia varied from clavate, fusiform to elongated, and measured between 17-24 μm x 4-8 μm. Basidiospores were ellipsoid, double walled of size 5-7.9 μm x 4-7.4 μm, and were hyaline in nature. The pleurocystidia showed clavate to pyriform shape, withthin wall and hyaline appearance, measuring 6.13-48.61 x 4.81-23.49 μm in size. The cheilocystidia, measured between 12.5-51.82 x 8.76-30.31 μm in size, and were clavate to elongated, thin walled and hyaline. Among the 28 samples, 10 were selected for molecular characterization based on their prevalence and prominence in distribution across the selected locations. The fungal genomic DNA was isolated, sequenced and in silico analysis with BLASTn output resulted in the identification of samples as T. eurrhizus (T12, W3), T. srilankensis (T13, T14, T15, W4), T. fuliginosus (T17), T. heimii (T18), T. microcrpus (W5), and Termitomyces spp. BAB 5063 (W1). A study was conducted to estimate the different nutritional parameters like carbohydrate, protein, crude fibre, Vitamin C, moisture percentage and ash content by adopting standard protocols. The carbohydrate content of Termitomyces spp. ranged between 31.2 to 46.9 g/100g on dry weight basis and recorded the maximum content of 46.9 g/100g in T. microcarpus. The protein content varied between 14.4 to 19.5 g/100g on dry weight basis with the highest amount of 19.5 g/100g in T. fuliginosus. The crude fibre content showed variation between 6.6 to 16.6 per cent, where, T. eurrhizus exhibited maximum per cent of crude fibre content of 16.6 per cent. The Vitamin C content ranged between 26.40 to 36.01 mg/100g with highest quantity in T. eurrhizus (36.01 mg/100g). Estimated moisture content of Termitomyces spp. was between 87.14 to 93.15 per cent, where T. srilankensis recorded the maximum amount of 93.15 per cent. Ash content of the samples ranged between 7.78 to 15.4 per cent, with T. fuliginosus recording maximum value of 15.4 per cent. The study documented the distribution of 28 Termitomyces species across diverse habitats in Central and Northern Kerala. Among these, T. microcarpus emerged as the most abundant species, with significant collections from Thrissur, Wayanad, and Kasaragod districts. The studied edible mushroom is nutritionally rich, containing substantial amounts of carbohydrates, proteins, crude fibre, vitamin C, ash, and moisture percentage in its sporocarps.Item Cataloguing and documentation of viral diseases in monopodial orchids in Kerala(Department of Plant Pathology, College of Agriculture,Vellanikkara, 2025) Puli Premsai.; Sumiya, K VThe Orchidaceae family, with over 28,000 species across 800 genera, is one of the largest flowering plants, renowned for its beautiful flowers and significance in global floriculture. Based on the growth habit, orchids are divided into monopodial and sympodial orchids. Vanda sp. Phalaenopsis sp., Mokara sp. Arachnis, Aranthera, and Arandra are commercially important monopodial orchids that hold value in South Asia's ornamental trade and traditional medicine. Kerala is known for its rich biodiversity; orchids are integral to the state's floral diversity. Kerala’s floriculture industry benefits from cultivation and marketing of orchid plants and flowers. However, viral infections, threaten orchid cultivation. Fifty-eight viruses are reported from orchids around the world, and ten viruses have been reported from India. Hence, this present study was undertaken to identify viruses infecting commercially grown monopodial orchids in Kerala A purposive sampling survey conducted in Thrissur, Palakkad, Malappuram, and Ernakulam districts of Kerala identified virus as a significant pathogen affecting monopodial orchids. The per cent disease incidence (PDI) of viral diseases in monopodial orchids ranged from 20 per cent to 86 per cent, with the highest PDI recorded from Thrissur district and the lowest PDI from Palakkad district. The per cent disease severity varied between 10 per cent and 84 per cent, with the highest severity from Malappuram district and the lowest from Thrissur district. Symptoms observed during the survey included black necrotic ring spots and specks with chlorosis on leaves, leaf mottling and crinkling and necrotic lines on Vanda sp., colour breaking in floral petals, floral crinkling, mosaic patterns and necrotic rings with chlorosis on leaves in Phalaenopsis sp. and chlorotic rings, necrotic lines, and chlorotic specks in Mokara sp. Virus culture maintained in a local lesion host, Chenopodium amaranticolor under an insect-proof net house showed typical local lesion symptoms. Transmission electron microscopy studies revealed the presence of two types of virus particles in infected samples; flexuous, filamentous particles of size 580nm indicating the presence of potexvirus, and straight rigid rods of approximate size 300 nm indicating the presence of tobamovirus. Total RNA was extracted from symptomatic monopodial orchid leaves and assessed for quality and quantity. Absorbance ratios (A260/280) close to 2 indicating good quality RNA. The RNA was converted to cDNA, which was also quantified and analyzed for purity. RT-PCR analysis using specific primers confirmed the presence of Odontoglossum ringspot virus (ORSV) in 12 samples (477 bp fragment) and Cymbidium mosaic virus (CymMV) in 20 samples (672 bp fragment). No samples tested positive for Groundnut bud necrosis virus (GBNV), Orchid fleck virus (OFV), or Calanthe mid mosaic virus (CalMMV). Molecular analysis using PCR confirmed the infection of CymMV, and ORSV in Vanda sp., Phalaenopsis sp., and Mokara sp. Amplicons from two representative samples of ORSV isolates one each from Vanda spp. (M1V1) and Mokara sp. (EM3) and two representative samples of CymMV isolates from Phalaenopsis sp. (TPP and EPP) were successfully sequenced. The resulting nucleotide sequences were analyzed and subsequently submitted to the NCBI GenBank database. These sequences were assigned accession numbers PQ571086 (ORSV M1V1 Malappuram), PQ571085 (ORSV EM3), PQ571087 (CymMV TPP) and PQ587541 (CymMV EPP). Homology analysis using NCBI BLAST of the sequences confirmed the presence of CymMV and ORSV in the samples. The homology analysis of the ORSV isolate M1V1 revealed a maximum sequence similarity of 100% to the coat protein (CP) region of ORSV isolate from China and ORSV isolate from Brazil. ORSV isolate, EM3 showed a maximum sequence similarity of 99.79% to the coat protein (CP) region of ORSV isolate from China and coat protein region of ORSV isolate from Sikkim. The CymMV isolates TPP and EPP showed maximum sequence similarity to isolate from Germany and CyMV 7 from China respectively. The predicted amino acid sequence of coat protein was derived from the nucleotide sequence using the Expasy tool. Alignment of amino acid sequences of CymMV isolates and ORSV isolates using the CLUSTAL Omega algorithm revealed that the coat protein region of both the viruses are highly conserved. A phylogenetic tree of the coat protein gene sequences of ORSV isolates from the present study (M1V1 and EM3) along with other ORSV isolates revealed two distinct clusters, indicating genetic divergence. The two isolates from the present study grouped with two different clades. ORSV M1V1 (Malappuram) grouped closely with isolates from China (MG869645) and Singapore (AF033848.1) in a moderately supported clade. In contrast, ORSV EM3 (Ernakulam) formed a sub-clade with isolates from Madagascar and Sikkim, India, indicating a closer evolutionary relationship with these regions. Phylogenetic analysis of CymMV isolates TPP and EPP along with other isolates of CymMV showed that both the isolates fall in separate subclades within a major clade. CymMV TPP (Thrissur) clusters with isolates from Germany and South Korea. At the same time, CymMV EPP (Ernakulam) forms a well-supported clade with isolates from Singapore (AF405721.1) and China (OQ615787), sharing closer evolutionary ties to Asian and European strains. CymMV was mechanically transmitted to Chenopodium amaranticolor, Datura stramonium and Vigna unguiculata, while ORSV was transmitted only to Chenopodium amaranticolor and Vigna unguiculata. Local lesions were observed in Chenopodium amaranticolor and Datura stramonium, while systemic infection was noticed in Vigna unguiculata. To conclude, viral disease symptoms were observed in monopodial orchids in orchid nurseries of central Kerala, with disease incidence varying from 20 per cent to 86 per cent. Cymbidium mosaic virus and Odontoglossum ringspot virus were the major viruses affecting monopodial orchids in Kerala. These viruses show a high degree of genetic similarity and phylogenetic relationship to the isolates reported from other Asian and European countries. These viruses are mechanically transmissible. This study highlights the urgent need for awareness of viral diseases and their spread among orchid nurseries for orchid growers and the adoption of strict phytosanitary quarantine measures to mitigate viral spread in India’s orchid industry. Molecular techniques such as meristem tip-culture techniques, and plant tissue-cultures techniques can be equipped for virus-free orchid production.Item Distribution and diversity of native isolates of Trichoderma Spp. of Kasaragod district(Department of Plant Pathology, College of Agriculture, Padannakkad, 2025) Linta Isac.The study entitled “Distribution and diversity of native isolates of Trichoderma spp. of Kasaragod district” was carried out in the Department of Plant Pathology, College of Agriculture, Padannakkad during 2021-23 with the objective of characterization of the native isolates of Trichoderma spp. from different agro ecological units of Kasaragod district to understand their distribution, diversity and antagonistic potential. A purposive sampling survey was conducted at different locations within the agro ecological units (AEU 2, 7, 11, 13 and 15) of Kasaragod district. The isolation of native Trichoderma spp. from the collected soil samples in Trichoderma Selective Medium (TSM) using the dilution plate technique yielded a total of fifty five isolates. Of these, ten isolates were from AEU 2 (Northern coastal plains), seventeen from AEU 11 (Northern laterites), four from AEU 13 (Northern foot hills) and twenty four from AEU 15 (Northern high hills). Notably, no isolate was obtained from AEU 7 (Kaipad lands). Correlation analysis between the different soil parameters and the occurrence of Trichoderma spp. demonstrated a positive but non-significant correlation with soil pH (r = 0.288, p = 0.246), organic carbon content (r = 0.274, p = 0.271), available P (r = 0.063, p = 0.804) and available K (r = 0.059, p = 0.817), whereas a negative non-significant correlation was observed with available N (r = -0.339, p = 0.168). The cultural characteristics of the isolates were examined on three different media, viz., PDA (Potato Dextrose Agar), RBA (Martin’s Rose Bengal Agar) and TSM (Trichoderma Selective Medium). Typically, the isolates exhibited the highest growth rate on PDA (3.02 cm per day), followed by RBA (2.18 cm per day) and TSM (2.08 cm per day). There was variation in colony morphology and spore characteristics among the isolates across the three media. The isolates produced conidia that were globose, sub globose, ellipsoidal and elongated. Additionally, flask shaped and pin shaped phialides were observed in clusters of two to three. Preliminary screening against Sclerotium rolfsii recorded more than 60 per cent inhibition in isolates Tr 5, Tr 12, Tr 37, Tr 38, Tr 40, Tr 41, Tr 43, Tr 48, Tr 52 and Tr 55, which were subsequently selected for further investigation. The antagonistic potential of these selected isolates against soil borne fungal pathogens, Pythium aphanidermatum, Phytophthora capsici, Rhizoctonia solani, Sclerotium rolfsii and Fusarium oxysporum f. sp. cubense was evaluated using the dual culture technique. The highest inhibition rate of 79.26 per cent against P. aphanidermatum was noticed in Tr 40, while cent per cent inhibition against P. capsici and R. solani was observed in the isolates, Tr 5, Tr 12, Tr 38, Tr 40, Tr 41 and Tr 43. The isolate, Tr 43 exhibited the maximum inhibition against S. rolfsii (82.96%) and Tr 40 exhibited the highest inhibition (73.33%) against F. oxysporum f. sp. cubense. All the isolates displayed cellulose hydrolyzing capacity, with Tr 43 recorded the highest value of 0.96. The compatibility of the isolates with the fungicides, copper hydroxide (0.1 %, 0.15% and 0.2 %), mancozeb (0.25 %, 0.3% and 0.35 %), carbendazim (0.15 %, 0.2% and 0.25 %), hexaconazole (0.15 %, 0.2% and 0.25 %) and metalaxyl (0.05 %, 0.1% and 0.15 %) and the insecticides, chlorpyriphos (0.05 %, 0.06% and 0.07 %) and carbosulfan (0.04 %, 0.05% and 0.06 %) was studied. The isolate Tr 55, showed relative compatibility with copper hydroxide and mancozeb at the concentrations, 0.15 and 0.3 per cent respectively. Carbendazim at all the tested concentrations exhibited cent per cent inhibition in all the isolates. The isolates exhibited more than 75 per cent inhibition with hexaconazole (0.2 %) and over 50 per cent inhibition with metalaxyl (0.1 %). The insecticides were relatively more compatible with the isolates. Particularly, isolates, Tr 5, Tr 12, Tr 41, Tr 43, Tr 48 and Tr 52 showed complete compatibility (zero inhibition) with carbosulfan at 0.05%. The molecular characterization of the isolates through ITS-PCR revealed Tr 5, Tr 12, Tr 38, Tr 41, Tr 43 and Tr 48 as Trichoderma asperellum; Tr 37, Tr 52 and Tr 55 as T. koningiopsis and Tr 40 as T. lixii. Furthermore, RAPD analysis employing six primers from the OPB series (OPB-1 to OPB-6) revealed the genetic polymorphism among the isolates. Out of the total 42 scorable bands, 41 were polymorphic and the per cent polymorphism was 97.62 per cent.Item Piriformospora indica- mediated degradation of strobilurin and triazole fungicides in tomato plants(Department of Plant Pathology, College of Agriculture,Vellayani, 2025) Austin Raj, K S.; Joy, MThe research work entitled “Piriformospora indica-mediated degradation of strobilurin and triazole fungicides in tomato plants” was carried out at the Department of Plant Pathology, College of Agriculture Vellayani, Thiruvananthapuram during 2022-24. The objective was to evaluate the beneficial fungal root endophyte, P. indica on degradation or retention of strobilurin and triazole fungicides used for the management of black leaf mold of tomato. P. indica-colonization in tomato var. Vellayani Vijai was done in the standardized medium. The presence of the chlamydospores was observed in roots of tomato at 5 days after colonization (DAC). P. indica-colonization was further confirmed using fungus-specific primer Pi-tef by PCR. Compatibility of P. indica was studied with fungicides such as azoxystrobin, pyraclostrobin, propiconazole and tebuconazole. P. indica is compatible with azoxystrobin and to some extend with pyraclostrobin; and incompatible with propiconazole and tebuconazole. P. indica exhibited 72 per cent compatibility with azoxystrobin at 50 ppm; while 19.72 per cent compatibility was observed with pyraclostrobin. P. indica could not grow in triazole fungicides, propiconazole and tebuconazole even at 50 ppm. Leaves with characteristic symptoms of black leaf mold of tomato were collected from Coconut Research Station, Balaramapuram. The symptoms were yellow and chlorotic spots on the upper leaf surface and black sooty mold on the corresponding lower surface. The fungus was isolated on potato dextrose agar (PDA) medium. The mycelial growth was grey on the upper side with concentric zonations, and black on the rear side. The margin of the growth was regular. The growth rate was observed as 1.1 mm per day. Koch’s postulate of the pathogen was proved by detached leaf assay. Symptoms started appearing from 5th day onwards. Symptoms were chlorotic lesion on the upper surface and black sooty growth on the lower surface of the leaf. In vitro evaluation of the pathogen against azoxystrobin, pyraclostrobin, propiconazole and tebuconazole was done by poisoned food technique. Both strobilurin and triazole fungicide significantly inhibited mycelial growth of 165 Pseudocercospora fuligena. Triazole fungicides such as propiconazole and tebuconazole were more effective in inhibiting the mycelial growth of P. fuligena than strobilurin fungicides. At 50 ppm, P. fuligena has grown 3.80 cm in azoxystrobin, 3.80 cm in pyraclostrobin, 1.37 cm in propiconazole and 1.21 cm in tebuconazole fungicides. P. fuligena growth was completely inhibited at 100 ppm of triazole fungicides; but at least 25 per cent fungal growth was observed in strobilurin fungicides even at 1000 ppm. A field experiment was conducted during the summer season (2023) at Coconut Research Station Balaramapuram. The first spray of fungicides was given at the vegetative stage ie., 40 days after sowing. The second spray of fungicides was given after fruit set stage ie., 70 days after sowing. The leaves and fruit samples were collected at 2 h, 24 h, 3, 5 and 10 days after spraying and residues were assessed by LC-MS/MS. P. indica enhanced the retention of the fungicide residues in leaves. The fungus also enhanced the degradation of the fungicides in tomato fruits which makes the fruits safer to eat. P. indica-colonization decreased the incidence and severity of diseases such as black leaf mold, Alternaria leaf spot, leaf curl and mosaic under natural incidence. When azoxystrobin was used, 64.05 per cent reduction of black leaf mold severity was observed over control at 60 days after transplanting. When propiconazole was used, 55.49 per cent reduction was observed. When azoxystrobin was used along with P. indica, the disease severity has been further reduced to 71.89 per cent; and when propiconazole was used along with P. indica, a reduction of 69.25 per cent was observed. Moreover, P. indica enhanced the growth parameters such as plant height, number of flowers per plant, number of fruits per plant and average yield per plant. Further P. indica decreased the number of days taken for flowering, 50 per cent flowering, fruit set and 50 per cent fruit set. Molecular basis of P.indica-mediated degradation of strobilurin and triazole fungicides was done at 3 and 7 days after the application of the fungicides. RNA was extracted and reverse transcribed into cDNA. GAPDH was used as the house keeping gene. Expression of genes involved in the degradation of strobilurin fungicides such as strH and Carboxyl esterase and Ergosterol gene involved in the degradation of triazole were studied. P. indica-colonization significantly enhanced the expression of Carboxyl esterase and Ergosterol genes in the fruits, thus increasing the fungicides degradation in fruits; whereas it repressed the expression of strH and Ergosterol genes 166 in leaves, thereby increasing the retention of fungicides in leaves under field conditions. Relative expression of the genes at 7th day after the application the fungicides was less compared to that at 3rd day. P. indica-colonization together with triazole or strobilurin fungicides application could effectively control the black mold disease caused by P. fuligena with enhanced biometric and yield characters of tomato. P. indica-colonization significantly enhanced the retention of the fungicides in leaves by down regulating the fungicide degrading genes; and degradation of fungicides in fruits by upregulating the fungicide degrading genes under field conditions with ecological sustainability and also to produce safe-to-eat tomatoes.Item Integrated management of fusarium wilt of yard long bean in homesteads(Department of Plant Pathology, College of Agriculture,Vellayan, 2025) Nimisha Haridasan.; Sajeena, AThe study entitled ‘Integrated management of Fusarium wilt of yard long bean in homesteads’ was undertaken at College of Agriculture, Vellayani and Integrated Farming System Research Station (IFSRS), Karamana during 2023-25 with an objective to develop an integrated management package for the vascular wilt of yard long bean incited by Fusarium oxysporum using bioagents and biofumigants in homesteads. The culture of F. oxysporum (accession no: MZ706472.1) maintained at IFSRS, Karamana was used for the study. The mycelia of the pathogen appeared as white and fluffy with a characteristic pale pink to purplish pigmentation. Microconidia were ovoid or elliptical with 0 - 1 septa, while macroconidia were fusiform with 3 – 4 septa. Chlamydospores were globose with a diameter of 6 -10 μm. The pathogen was mass multiplied in sorghum-sand medium (SSM) (2:1:1 ratio) and complete colonization of the fungus was recorded at 5 days after inoculation (DAI). Koch’s postulates were proved in 15-days-old yard long bean seedlings (var. Githika). The disease symptoms initiated as yellowing of older leaves at 7 days after transplanting, which further progressed as defoliation, withering, wilting and seedling death. In vitro studies on the evaluation of antifungal potential of bioagents, botanicals and biofumigants revealed that garlic bulbs (2 g plate-1) completely (100%) inhibited the pathogen. Rhizobium sp. (KAU) inhibited the mycelial growth by 67.77 per cent and tested positive for siderophore production, indicated by a colour change of Chrome Azurol S (CAS) agar from blue to orange. In vivo seed treatment studies revealed that sowing of seeds in soil applied with AMF @ 5 g seed-1 followed by transplanting was the promising treatment (no incidence of disease) for the management of Fusarium wilt, along with enhanced seed germination (100%), leaf number (11.00), leaf area (24.17 cm2), shoot length (16.17 cm), root length (19.83 cm) and root-shoot ratio (5.33) of the seedling. Seed treatment with Rhizobium sp. followed by transplanting was the next promising treatment with the highest leaf area (27 cm2). Scanning electron microscopy revealed intact cell structure and absence of clogging 128 in vascular tissues of the above plants where as the pathogen inoculated control recorded its hypha emerging out of xylem vessels, which were damaged and extensively clogged. A pot culture study was undertaken in yard long bean var. Githika to develop an integrated package for management of vascular wilt disease. The treatment viz., soil testbased lime application at 2 weeks before planting + soil application of Trichoderma sp. enriched in cow dung – neem cake mixture (9:1) @ 1 kg pot-1 at one week before sowing (WBS) + soil application of AMF @ 5 g seed⁻¹ at sowing followed by transplanting + soil application of PGPR mix II @ 20 g L-1 at 20, 40 and 60 DAS (T6), recorded the least disease incidence (55.50%) and disease severity (19.44%), with the highest yield (945 g plant-1with 54 pods), among the treatments. The highest AMF root colonization (49%) and number of nodules (47.00) were also recorded in this treatment. Significant reduction in the population of the pathogen in soil/ pot was also recorded in this treatment at 30 and 60 DAS. The next promising treatment was same as the best one, with soil application of PGPR mix II @ 20 g L-1 replaced by Trichoderma sp. enriched in cow dung – neem cake mixture (9:1) @ 1 kg pot-1 at 20, 40, and 60 DAS (T3) which recorded reduced disease incidence (66.66%) and severity (31.76%) with higher yield (908.33 g plant-1from 50.00 pods), AMF root colonization (45.00%) and nodules (40.67). Peak activity of peroxidase (12.07 μg g-1 min-1), polyphenol oxidase (1.587 μg g-1 min-1), and phenylalanine ammonia lyase (11.703 μg g-1 min-1) at 72 hours after inoculation was recorded in the promising treatment. Thus, the present study revealed the integrated disease management package viz., soil test-based lime application at 2 weeks before planting + soil application of Trichoderma sp. enriched in cow dung – neem cake mixture (9:1) @ 1 kg pot-1 at one WBS + soil application of AMF @ 5 g seed⁻¹ at sowing followed by transplanting + soil application of PGPR mix II @ 20 g L-1 at 20, 40 and 60 DAS can effectively manage vascular wilt of yard long bean incited by F. oxysporum in homesteads. Furthermore, the study confirms a beneficial quadripartite association among AMF, Trichoderma sp. and the plant growth promoting rhizobacteria in yard long bean plants, as observed from the 129 effective management of the disease and enhanced plant growth and yield attributes even in the presence of the soil borne pathogen.