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 Propagation studies in miracle fruit [Synsepalum dulcificum (Schumach. and Thonn.) Daniell(Department of Fruit Science, College of Agriculture, Vellanikkara, 2025) Hana, V AnvarMiracle fruit [Synsepalum dulcificum (Schumach. & Thonn.) Daniell] is an exotic evergreen shrub belonging to the family Sapotaceae, native to West Africa. The fruit is renowned for its unique taste-modifying property attributed to the glycoprotein miraculin, which temporarily converts sour taste into sweet. In addition to this remarkable sensory feature, various parts of the plant possess notable pharmacological properties, including antioxidant, antidiabetic, anticancer, and antihyperuricemic activities, attributed to its rich composition of bioactive compounds such as flavonoids, phenolics, and triterpenoids. These attributes make miracle fruit a promising functional and nutraceutical crop with growing global demand. Despite Kerala’s favourable agro- climatic conditions, the commercial cultivation of miracle fruit remains limited, as its propagation presents considerable challenges affecting large-scale multiplication. Hence, the present study entitled “Propagation Studies in Miracle Fruit [Synsepalum dulcificum (Schumach. & Thonn.) Daniell]” was conducted during 2024–2025 in the Department of Fruit Science, College of Agriculture, Vellanikkara, with the objective of standardizing efficient propagation methods of miracle fruit suitable for Kerala conditions. The research programme comprised two major experiments viz standardization of media for seed propagation and evaluation of vegetative propagation techniques. The first experiment on seed propagation was conducted in CRD with five treatments and three replications, using ten seeds per replication. The media evaluated were: soil (T₁–control), soil + cocopeat + FYM (2:1:1) (T₂), soil + cocopeat + vermicompost (1:1:1) (T₃), sawdust (T₄), and sawdust + vermicompost (1:1) (T₅). Results revealed that seeds sown in T₅ significantly outperformed other treatments, recording the earliest germination (12.00 days), highest germination percentage (53.33%), maximum seedling height (7.51 cm) and seedling weight (0.80 g), 90 DAS. Meanwhile, T₃ was superior in vegetative growth parameters, producing the highest number of branches (3.83, 120 DAS), leaves (4.17, 90 DAS), and stem girth at 10 cm height (0.20 cm, 120 DAS). In contrast, soil + cocopeat + FYM (2:1:1) (T₂) recorded the lowest germination rate, while soil alone (T₁) and sawdust (T₄) required the maximum days for germination and exhibited poor seedling development. The experiment on terminal cuttings was conducted in CRD with eight treatments, three replications, and ten cuttings per replication. Various growth regulators and natural rooting substances were tested to assess their effect on root induction and growth: 400 ppm IBA (T₁), 800 ppm IBA (T₂), 500 ppm NAA (T₃), 1000 ppm NAA (T₄), Rootex (T₅), Aloe vera gel (T₆), dry control (T₇), and wet control (T₈). Results revealed significant variation among treatments in their rooting response. Cuttings treated with 800 ppm IBA (T₂) recorded the maximum number of rooted cuttings (6.66), roots per cutting (2.86), root length (11.96 cm), and survival rate (44.40%) at 120 days after planting. In contrast, dry and wet controls (T₇ and T₈) showed poor rooting performance. However, no sprouting, leaf emergence, or shoot formation was observed in any of the treatments during the experimental period. The air layering experiment was conducted with six different media treatments, arranged in CRD with three replications and five air layers per replication. The treatments comprised cocopeat (T₁), sawdust (T₂), sphagnum moss (T₃), coirpith compost (T₄), vermicompost (T₅), and a mixture of perlite, vermiculite, and AMF (1:1:1) (T₆). Results revealed significant variation among the media used for air layering, with vermicompost (T₅) showing the earliest root emergence (47.66 days), maximum number of rooted layers (3.00), and highest survival rate (20%) after three months. Both vermicompost (T₅) and perlite + vermiculite + AMF (1:1:1) (T₆) required the minimum duration for separation (182.00 days). The T₆ medium also produced the highest number of adventitious roots (5.33), longest root length (7.36 cm), and most side shoots (2.66). In contrast, sawdust (T₂) and coirpith compost (T₄) performed poorly across all parameters, exhibiting delayed rooting and no survival. The experiment on grafting was laid out in a CRD with two factors viz season (June, July, and August) and method of grafting (softwood, side, and veneer), comprising nine treatment combinations. Each treatment was replicated three times with five grafted plants per replication. Results revealed significant effects of both season and grafting method on the growth and survival of grafted miracle fruit plants. Grafts performed in August (S3) showed superior performance with earliest sprouting (23 days), highest number of leaves (16.16), more branches (4.46), and maximum survival (48.92%), 90 days after grafting, while grafts in June (S1) recorded the longest shoots (2.73 cm). Among the methods, softwood grafting (G1) proved most effective, producing earliest sprouting (19 days), highest leaf (17.33) and branch count (4.81) and maximum survival (55.59%), 90 days after grafting, whereas veneer grafting (G3) performed the poorest. The interaction effect between season and method was also significant. Softwood grafting during August (S₃G₁) resulted in the overall best performance, with maximum leaves (22.83), branches (6.16), and survival (73.44%), whereas side grafting during June (S₁G₂) produced the longest shoots (4.03 cm). In contrast, veneer grafting in June (S₁G₃) recorded the lowest growth and survival. The budding experiment was conducted in a Completely Randomized Design (CRD) with two factors—season and method of budding. The seasons evaluated were June (S₁), July (S₂), and August (S₃), while the methods included patch budding (B₁) and chip budding (B₂). Although the experiment initially comprised six treatment combinations, chip budding (B₂) failed to sprout or survive in any of the seasons and was therefore excluded from statistical analysis. Consequently, data analysis was carried out using CRD, considering only the patch budding treatments. Significant variations were observed among seasons, with budding performed in June (S₁) showing superior performance in all growth parameters, including the earliest sprouting (57.00 days), highest leaf number (10.80), branch count (2.56), and shoot length (3.26 cm) at 90 days after budding. The highest survival rate (93.33%) was recorded for patch budding in June, which was statistically on par with August (80.00%). Thus, patch budding carried out in June (S₁B₁) proved to be the most effective treatment, resulting in the earliest sprouting, enhanced vegetative growth, and maximum survival percentage under Kerala conditions. Overall, the study revealed that propagation success in miracle fruit varied considerably under Kerala conditions. Seed propagation was limited by the long juvenile phase of seedlings, while cuttings and air layering exhibited poor rooting and survival, making them unsuitable for large-scale multiplication. In contrast, grafting and budding performed well, with patch budding in June emerging as the most successful and reliable method, followed by patch budding and softwood grafting in August, for efficient propagation of miracle fruit under Kerala conditions.Item Characterization of blast pathogen in finger millet and the biochemical and molecular mechanisms of diseas resistance.(Department of Plant Pathology, College of Agriculture,Vellayani, 2025-12-22) Sneha Mohan; Anupama,TVThe study entitled “Characterization of blast pathogen in finger millet and the biochemical and molecular mechanisms of disease resistance” was carried out at the Department of Plant Pathology, College of Agriculture, Vellayani, during 2023-2025 with the objective of characterization of blast pathogen in finger millet, varietal screening for resistance and evaluation of biochemical and molecular mechanisms of disease resistance. A field survey was conducted across six agro-ecological units (AEUs) of Kerala viz., AEU 3, AEU 8, AEU 11, AEU 15, AEU 16 and AEU 18 covering the districts of Alappuzha, Thiruvananthapuram, Kasaragod, Palakkad, and Idukki. Ten locations were surveyed, and leaf samples showing typical blast symptoms were collected. The symptoms ranged from small brown specks to spindle-shaped lesions with greyish-white centre and yellowish-brown margin, which often coalesced, giving a blighting appearance. Disease incidence and severity were recorded, with the highest incidence (56.33%) and severity (52.60%) observed in Santhanpara region of Idukki district. Correlation analysis revealed a positive relationship between disease parameters and relative humidity, and a negative correlation with maximum temperature. Twelve isolates of the pathogen were obtained from diseased samples, and pathogenicity was confirmed through artificial inoculation on one month old finger millet plants. Cultural and morphological characterization revealed colony colours ranging from greyish-white to black, with flat to raised mycelium and brown to black pigmentation on potato dextrose agar (PDA). The isolates took 13–15 days for full plate coverage (90 mm). Microscopic examination showed hyaline, septate mycelia with two-septate, three- celled, pyriform conidia. Among the isolates, the Vellayani isolate (P4) showed the fastest growth (growth rate of 0.77 cm/day) and highest virulence, producing symptoms within 5 days, with an average of 14.7 lesions per leaf and lesion size of 2.05 × 0.47 cm. Plants inoculated with P4 exhibited the highest disease severity (75.30%), identifying it as the most virulent isolate. Symptom development and sporulation studies with the isolate P4 were conducted and observed that symptoms appeared on 5 days after inoculation (DAI), whereas 135 sporulation began at 10 DAI. Morphological observation showed erect, hyaline conidiophores bearing successively arranged, pale-brown, two-septate, pyriform conidia with a pointed apex and basal hilum. The physiological studies of the pathogen were conducted by growing on different media (PDA, Oatmeal agar, Host extract +2% sucrose agar, Ragi yeast lactose agar and Water agar), temperature (15℃, 20℃, 25℃, 30℃ and 35℃) and light intensity (1000 lux, 2000 lux, 3000 lux, 12 hours darkness and 12 hours light and complete darkness). The results showed highest mycelial growth on PDA medium, at 25 °C, and under complete darkness. Molecular characterization using LSU primers confirmed the identity of the virulent isolate as Pyricularia grisea. The nucleotide sequence was submitted to GenBank under the accession number PX369007. Twenty finger millet accessions (10 indigenous and 10 high-yielding types) were screened against P. grisea. The results revealed that accessions Aduvilanthankudy, Attappady Ragi Millet Mission, Ramapuram, and GPU 28 were resistant; Cherthala South, Pachamutti, Neelikuzhy, Co 15, ATL-1, ML-365, Vakula, Tirumala, and CFMV-1 were moderately resistant; while Kadukumanna, Mattakkavu, Sirukkorai, Palakkini, PPR 1170, and VL 408 were susceptible and KMR 301 was highly susceptible. Aduvilanthankudy recorded the lowest percent disease index (PDI) of 19.24% and a disease score of 1.73, whereas KMR 301 showed the highest susceptibility (PDI 84.73%). Yield assessment revealed that GPU 28 had the highest yield (8.10 g/plant), while Aduvilanthankudy recorded the highest yield among indigenous accessions (7.15 g/plant). Biochemical assays were conducted on resistant (Aduvilanthankudy) and susceptible (KMR 301) accessions at 24, 48, and 72 hours after inoculation (HAI). Defense-related enzymes—peroxidase, polyphenol oxidase, and catalase showed significantly higher activity in the resistant accession, with early peaks at 24 HAI. Phenylalanine ammonia lyase (PAL) and superoxide dismutase (SOD) exhibited delayed but sustained maximum activity at 72 HAI in the resistant plants, indicating their role in defense response. Gene expression analysis using quantitative Real-Time PCR (qRT-PCR) conducted five days after inoculation revealed upregulation of defense-related genes PAL and EIN2 in the resistant accession Aduvilanthankudy, showing relative fold changes of 2.90 and 1.34, respectively, compared to the susceptible KMR 301. The study concludes that the blast pathogen prevalent in Kerala finger millet ecosystems is Pyricularia grisea. The indigenous accession Aduvilanthankudy displayed strong resistance, characterized by early activation of key defense enzymes and higher expression of defense genes. This genotype will be a promising source of resistance for incorporation into breeding programs aimed at developing high-yielding, blast-resistant finger millet accessions adapted to regional climatic conditions and pathogen pressure.Item Cultivation techniques of edible tropical mushroom,Macrocybe sp.(Cultivation techniques of edible tropical mushroom,Macrocybe sp., 2025-12-04) Sona jaisonThe genus Macrocybe, belonging to the family Callistosporiaceae within the phylum Basidiomycota, represents a distinct group of large agaric mushrooms characterized by their exceptionally massive fruiting bodies, which commonly occur in clusters on decaying organic substrates. The name Macrocybe is derived from two Greek words “makros” (long) and “kube” (head), which denotes the remarkable size of its sporophores. To date, eight species have been reported within this genus, among which Macrocybe gigantea is the most extensively studied. It is also the most widely distributed species, particularly across the tropical and subtropical regions. Members of Macrocybe are well known for their edibility, fleshy texture, and appealing flavour, which emphasize their potential for commercial cultivation and nutritional utilisation. Hence, the present study was undertaken to standardise the techniques for in vitro culturing, spawn production, and cultivation of Macrocybe species under Kerala conditions. Mushroom samples morphologically resembling Macrocybe, were collected during the summer showers of 2024 from three distinct locations across Kerala viz., Malappuram (MAL-1), Thrissur (MEL-1), and Kottayam (KTM-1) districts. Tissue isolation was carried out on potato dextrose agar medium under aseptic conditions. A white, cottony mycelial growth was observed around the inoculated tissue after 14 days of incubation from the sample MAL-1, whereas white, fluffy growth appeared within 8 days from the sample MEL-1. However, the sample collected from Kottayam (KTM-1) failed to establish under in vitro. Molecular characterisation was performed to confirm the identity of the isolates, revealing that sample MAL-1 corresponded to Calocybe indica, while sample MEL-1 was identified as Macrocybe gigantea. The confirmed M. gigantea isolate (MEL-1) was subsequently maintained on potato sorghum dextrose agar slants at 4 ± 1°C and utilized for further experimental studies. In vitro experiments were conducted to standardise the culture medium and its components for optimizing the mycelial growth of M. gigantea under both solid and liquid conditions. Among the different media tested, potato sorghum dextrose medium supported the most vigorous mycelial growth, and sucrose was identified as the most effective carbon source. The experiments on standardisation of pH and temperature revealed pH of 5 and temperature 30 ± 2 °C to be optimum for in vitro culturing of M. gigantea. Upon standardisation of light conditions, incubation under blue light and complete darkness were found to produce maximum growth with dense mycelia. In vivo experiment was conducted to standardise suitable substrate for spawning, bedding and casing material for the cultivation of M. gigantea under Kerala conditions. Sorghum was proved to be the most effective spawn substrate among the different grains tested, showing mycelial initiation within six days and completing the spawn run in 9.67 days with thick and fluffy growth. Paddy straw was identified as the best bedding substrate, supporting the fastest crop cycle with 10.67 days for spawn run, 10 days for pinhead initiation, and 13 days for the first harvest after pinhead formation, completing a full crop cycle in 33.66 days. The sporophores produced on paddy straw were healthy and well-developed, with an average stipe length of 11.33 cm and a pileus diameter of 9.89 cm. Paddy straw also recorded the highest biological efficiency (51.95%) and the maximum benefit–cost ratio (4.08). Among the casing materials tested, vermicompost applied at 5 cm thickness proved to be the most suitable, requiring only 8.3 days for case run, 19.33 days for pinhead initiation, and 30 days for the first harvest after casing. It produced well-developed sporophores with an average stipe length of 10.7 cm and a pileus diameter of 9.7 cm, achieving the highest biological efficiency (58.86%). The proximate composition analysis of M. gigantea revealed 27.30 per cent protein, 4.15 per cent fat, 6.5 per cent carbohydrate, 2.66 per cent crude fibre, and 7.95 per cent ash on a dry weight basis, with a moisture content of 87.50 per cent on a wet weight basis. The post-harvest shelf life of fresh mushroom sporophores was found to be greatly influenced by the type of packaging material and storage conditions. At room temperature, sporophores stored in non-perforated polypropylene covers remained free from spoilage for 6.3 days, whereas those stored under refrigerated conditions in perforated polypropylene covers exhibited an extended shelf life up to 16 days. Organoleptic evaluation conducted in comparison with Agaricus sp. revealed that M. gigantea possessed superior sensory qualities in terms of colour, taste, flavour, appearance, and texture. Overall, M. gigantea emerges as a high-yielding and highly palatable species, destined to be a valuable new addition to the basket of cultivated mushrooms.Item Postharvest quality management of avocado (persea ameicana mill ) C V.Arka Supreme(Department of Postharvest Management, College of Agriculture, Vellanikkara, 2025-12-02) Miyandra Martin; Anu Mary MarkoseAvocado (Persea americana Mill) is a subtropical climacteric fruit originating from south-central Mexico and Guatemala that has gained global popularity owing to its rich nutritional composition. The fruit is valued for its high energy content, healthy monounsaturated fats that support heart health and is a good source of protein, potassium, and various vitamins. Despite its value, avocados are highly perishable due to their climacteric nature, characterised by a surge in ethylene production immediately after harvest, leading to rapid ripening and spoilage, within 5-6 days of storage, resulting in significant economic losses. The present study, entitled ‘Postharvest quality management of avocado (Persea americana Mill) cv. Arka Supreme’ was carried out at the Department of Postharvest Management, College of Agriculture, Vellanikkara, during 2023-2025 to standardise the postharvest treatments for delayed ripening and shelf life extension in avocado by the application of ethylene inhibitors and maintenance of optimum storage temperatures. The first experiment evaluated the efficacy of various ethylene inhibitors, including Salicylic acid (SA), Sodium nitroprusside (SNP), and 1- Methylcyclopropene (1-MCP) at different concentrations. The control fruits were spoiled and discarded after 6 days. SA and SNP treatments extended shelf life to 12 days, while 1-MCP treatments were superior, extending the shelf life to 15 days. Although statistical comparisons were made up to the 12th day (other treatments became unmarketable) fruits treated with 500 ppb 1-MCP remained marketable up to 15 days with highest quality attributes like lowest respiration rate (395.99 mg CO2 kg-1 h-1), ethylene production rate (88.95 μL kg-1 h-1), and physiological loss in weight (9.64 %) while maintaining the highest fruit firmness (1.86 kg cm-2), titratable acidity (0.2 %), total sugars (1.13 %), and moisture content (75.37 %) with the slowest increase in total soluble solids (7.15 °Brix) and oil content (9.91 %). Treated fruits also exhibited the highest retention of total phenolic content (75.51 mg 100 g-1), total flavonoids (32.87 mg 100 g-1), antioxidant activity (IC50 value 4.08), and peroxidase (POD) activity (1.9 U mL-1) with the lowest polyphenol oxidase (PPO) activity (3.16 U mL-1). The highest total score (60.9) in sensory evaluation also confirms 500 ppb 1-MCP as the most effective treatment. In the second experiment, the best treatment from the first experiment (500 ppb 1-MCP) was utilised to assess the effect of storage temperature on the quality and shelf life of avocado. The fruits stored under ambient temperature (30 ± 2 ℃) were discarded due to spoilage by the second week itself. Refrigerated storage (4-7 ℃) extended shelf life to 21 days, but caused severe chilling injury, negatively impacting quality. Cold storage (10 ± 2 ℃) was found to be the most effective in extending shelf life up to 37 days, retaining quality attributes like the lowest respiration rate (292.93 mg CO2 kg-1 h-1), ethylene production rate (27.25 μL kg-1 h-1), physiological loss in weight (7.57 %) and highest fruit firmness (1.98 kg cm-2). Total soluble solids (7.1 °Brix) and oil content (9.14 %) increased slowly, reaching peak values only by the 5th week. The treatment was also superior in retaining quality, with the highest titratable acidity (0.29 %), total sugars (1.21 %), moisture content (76.38 %), total phenolic content (78.52 mg 100 g-1), and total flavonoids (34.28 mg 100 g-1). It also maintained the highest antioxidant activity (IC50 value 4.09), peroxidase (POD) activity (1.97 U mL-1) and the lowest polyphenol oxidase (PPO) activity (3.09 U mL-1) along with the highest organoleptic score of 58.0 by the end of the 5th week. Pearson’s correlation analysis revealed strong relationships between ethylene production and other quality attributes of avocado. Ethylene evolution showed positive correlations with oil content, respiration rate, total soluble solids, and antioxidant activity, and negative correlations with firmness, titratable acidity, sugars, flavonoids, and moisture, indicating its key role in fruit ripening dynamics. The present study demonstrated that the combination of 1-MCP (500 ppb) and cold storage (10 ± 2 ℃) preserved the fruit’s physiological and biochemical quality by delaying the climacteric surge, successfully extending its shelf life from 6 days to 37 days. This research offers an effective strategy to mitigate postharvest losses and thereby promote a more stable and sustainable avocado supply chain.Item High temperature stress on grain phytic acid and mineral bioavaility in rice(Department of plant physiology, College of Agriculture,Vellayani, 2025-11-28) Lishli,D; Beena,RThe study entitled “High temperature stress on grain phytic acid and mineral bioavailability in rice (Oryza sativa L.)” was conducted at the Department of Plant Physiology, College of Agriculture, Vellayani, during 2023–2025. The present study examined the influence of high temperature stress (36 ± 2°C) imposed during the reproductive stage on grain phytic acid accumulation, mineral bioavailability, physiological performance, and yield traits in eleven rice genotypes differing in pericarp colour and stress tolerance. The experiment was conducted during the Rabi 2024 season using a Completely Randomized Design (CRD) with two temperature regimes (ambient and high temperature) and three replications. The plants were maintained under normal conditions until panicle initiation and after which they were exposed to high temperature condition in a polyhouse. Morphophysiological, biochemical, and molecular parameters, including the expression of the SPDT (SULTR-like Phosphorus Distribution Transporter) gene, were analysed to elucidate the molecular basis of genotypic variation in phytic acid content. High temperature stress significantly affected physiological, biochemical, and yield parameters, though the extent of response varied among genotypes. Exposure to elevated temperatures resulted in a 7–18 % reduction in plant height, a 21–51 % decrease in leaf area, and a 15–32 % decline in chlorophyll content. Yield related traits were also adversely affected, with spikelet fertility declining by 2–15 % and grain yield decreasing by 18–50 % due to elevated temperature. Pigmented rice genotypes such as Kalabath and Assam Black maintained higher chlorophyll retention, membrane stability, and yield indicating strong thermotolerance. In contrast, white pericarp genotypes such as Khira, White Jasmine, and Jeerakasala exhibited substantial reductions in photosynthetic efficiency and spikelet fertility, resulting in greater yield losses. Jyothi and Urunikaima demonstrated moderate tolerance, with intermediate stability under stress Under heat stress, a significant biochemical response was evident, reflected by a 2–34 % increase in grain phytic acid compared to plants grown under ambient conditions. This increase reflects a temperature-induced shift in phosphorus metabolism that helps stabilize internal phosphorus reserves. However, it was accompanied by a 20–30% reduction in bioavailable iron and zinc, demonstrating a strong negative correlation between phytic acid accumulation and mineral bioavailability. Molecular analysis revealed that the SPDT gene, responsible for phosphorus transport to grains, was upregulated under stress, thereby promoting enhanced phytic acid biosynthesis. Bran colour exerted a strong influence on stress response and nutrient balance. Pigmented genotypes, particularly those with black and red pericarps, exhibited only a 10–15% reduction in antioxidant activity compared with 25–30% in white rice. Their higher levels of phenolics, anthocyanins, and flavonoids likely mitigated oxidative injury, preserving grain integrity and mineral stability. Conversely, white genotypes, lacking such antioxidant protection, experienced a stronger rise in phytic acid and greater yield decline. In conclusion, high temperature stress during the reproductive stage significantly influenced grain phytic acid content, mineral bioavailability, and yield parameters in rice, with the magnitude and nature of these effects varying among genotypes of different bran colours. The results demonstrate that the increase in phytic acid under heat stress is a protective yet nutritionally disadvantageous response associated with altered phosphorus metabolism and reduced mineral availability. The observed inverse relationship between phytic acid accumulation and mineral bioavailability underscores the importance of developing rice genotypes with optimized phosphorus transport and enhanced thermotolerance. The study thus fulfilled its objective by identifying pigmented genotypes such as Kalabath and Assam Black as promising donor lines combining superior antioxidant potential, balanced phytic acid regulation, and stable mineral bioavailability, providing valuable resources for breeding climate-resilient and nutritionally enriched rice cultivars.Item Farmers perception towards electronic- national agriculture market (e-NAM) platform with reference toAPMC market,Haryana(College of Co-operation,Banking &Management, vellanikkara, 2023) Piyush PaulItem Financial performance of Dindigul central co-operative bank,Tamilnadu(vellanikkara College of Co-operation,Banking &Management,Vellanikkara, 2023) Raja Priyadharshini,SItem Workers satisfaction towards welfare measures At palm fibre,Alappuzha(College of Co-Operation,Banking and Management,Vellanikkara, 2023) Jain,AmruthaItem Seed invigouration and weed management for enhancing productivity in aerobic rice (Oryza sativa L.)(Department of Agronomy, College of Agriculture , Vellayani, 2025) Aswin Mohan; Sheeja, K RajThe experiment entitled “Seed inviguoration and weed management for enhancing productivity in aerobic rice (Oryza sativa L.) was conducted at College of Agriculture, Vellayani, Kerala during the period 2022-2024. The investigation pertaining to the study comprised two experiments. A pot culture experiment was conducted to assess the seed invigouration potential of liquid organic manures and field experiment to study the effect of seed invigouration and weed management regimes for higher productivity in aerobic rice. Pot culture experiment was conducted in September 2023 at the College of Agriculture, Vellayani. The experiment followed a completely randomized design (CRD) with 18 treatments in three replications. Treatments included beejamrit, jeevamrit, panchagavya, and vermiwash at 2.5 per cent, 3 per cent, 5 per cent, and 6 per cent concentrations, along with hydropriming and no priming. Seeds of Prathyasa variety were primed for 16 h and dried to original moisture before sowing. Seed priming with liquid organic manures significantly influenced seed germination parameters, seedling attributes, and vigor indices in rice. Among the treatments, beejamrit at 6 per cent concentration recorded higher germination percentage (90.0%), while beejamrit 5 per cent achieved the highest germination rate index (21.6). However, vermiwash 5 per cent proved superior in terms of overall germination performance, registering the highest germination index (125.3), greater speed of germination, and mean daily germination (2.1 no. d-1). In addition, the coefficient of rate of germination was higher in vermiwash 3 per cent (21.4). The shortest mean germination time (5.2 d) was observed with panchagavya 3 per cent. Beejamrit 6 per cent resulted in higher seedling vigor index I (3123) which was statistically on par with vermiwash at 3 per cent, 5 per cent, and 6 per cent, as well as panchagavya 5 per cent. In terms of seedling vigor index II, the higher value was observed with vermiwash 6 per cent (6.64), and was on par with vermiwash 5 per cent(6.49). Based on the total scores, seed priming with 5 per cent and 3 per cent vermiwash concentrations which scored the highest scores of 253 and 237, respectively, were selected for further evaluation under field condition The field experiment was conducted at the organic farm of Department of Agronomy from January to May 2024, in randomized block design (RBD) with three factors. The first factor was two levels of seed priming [vermiwash 3 per cent (p1) and vermiwash 5 per cent (p2)] and a control (unprimed seeds). The second factor consisted of various weed management regimes [wheel hoe weeding (WHW) performed three times at 15, 30, and 45 DAS (r1), live mulching with cowpea followed by WHW at 45 DAS (r2), Gliricidia maculata leaf mulching at 10 t ha-1 followed by WHW at 30 and 45 DAS (r3), hand weeding (HW) thrice at 15, 30, and 45 DAS (r4), and weedy check (r5)]. The Prathyasa variety of rice was used for the study. Seeds were sown using a seed drill, and cowpea seeds were sown for live mulching at 7 DAS of rice and was uprooted and spread at 45 DAS during wheel hoe weeding. Similarly, Gliricidia maculata leaf mulching was also done on 7 DAS. At 15, 45, and 60 DAS, the treatment combination p2r5 resulted in taller plants. However, at 30 DAS and harvest, p1r3 and p2r3 produced taller plants, respectively. Tillers m² were higher in p2r1 at 30 and 60 DAS, though it was on par with p2r3 at 30 DAS and p2r4 at 60 DAS. At 45 DAS, p2r4 produced a greater number of tillers m², and at harvest, p2r3 had a greater number of tillers m². Dry matter production per plant was found to be higher in p2r4 at 15 DAS, and at the remaining stages, p2r3 resulted in higher DMP per plant. The treatment combination p2r1 exhibited higher LAI at 30, 45, and 60 DAS. The chlorophyll content was higher in p2r1 at 15 DAS, p1r2 at 30 DAS, and in treatments p1r3, p2r1, p2r2 and p1r3 at 60 DAS. At 30 DAS - 45 DAS and 60 DAS - harvest, p2r3 resulted in higher crop growth rate (CGR) (4.74 g m² d⁻¹ and 11.96 g m² d⁻¹, respectively). However, at 45 DAS - 60 DAS, p3r3 exhibited the highest CGR (10.85 g m² d⁻¹). For 15 DAS - 30 DAS, p1r1 resulted in higher relative growth rate (RGR) (0.228 g g⁻¹ d⁻¹). However, at 45 DAS - 60 DAS, p3r3 resulted in significantly higher RGR (0.063 g g⁻¹ d⁻¹), and from 60 DAS - harvest, p1r5 showed the highest RGR (0.038 g g⁻¹ d⁻¹). The number of days to 50 per cent flowering ranged between 54 and 59 days across treatments, with the earliest flowering in seeds primed in p2r4 (vermiwash 5% + hand weeding thrice) (54 days). The treatment combination p2r2 had greater number of panicles m-2 (236 no. m-2) and 1000 grain weight, whereas, p2r4 had greater number of grains per panicle and p2r3 had higher panicle weight. The treatment combination, p2r3 resulted in significantly higher grain yield (2625 kg ha-1), straw yield and harvest index. Compared to p2r4 (unprimed seeds + hand weeding thrice), the percentage increase in grain yield observed in p3r3 (seeds primed in vermi wash 5 per cent concentration + G. maculata green leaf mulching with 10 t ha-1 fb WHW at 30 and 60 DAS) was 48.8 per cent. Weed infestation significantly reduced grain yield in aerobic rice. Among the treatment combinations, p3r5 recorded the highest weed index of 71.5 per cent. Among the quality parameters, the treatment combination, p3r1 resulted in higher starch content and was on par with all treatments except p1r1 and p3r4. At 15 DAS, p1r3 resulted in lower absolute density of BLW, however at 30 DAS, 45 DAS and 60 DAS, p2r4 registered lower absolute density of BLW. The absolute density of grasses was found to be lower in p2r2 and p3r5 at 15 DAS, p1r1 at 30 DAS, p2r1 at 45 DAS and p2r1 and p3r3 at 60 DAS. However, p1r3 resulted in lower total density of weeds at 15 DAS and p2r4 at the remaining stages. Weed dry weight was observed to be lower in p1r3 at 15 DAS and p2r4 at 30 DAS, 45 DAS and 60 DAS. Weed control efficiency also followed the same trend as that of weed dry matter. Nitrogen and P removal by weeds were observed to be lower in p2r4 at 30 DAS and 60 DAS. However, p2r4 showed lower K removal at 30 DAS and p3r4 at 60 DAS. The treatment combination, p2r2 resulted in higher N uptake by aerobic rice (72.6 kg ha-1) and it was followed by p2r3. However, p2r3 and p2r2 resulted in higher P uptake by aerobic rice (12.0 kg ha-1) and K uptake by p2r3 (48.4 kg ha-1). Interaction between seed priming and weed management regimes had significant effect only on organic carbon content and the treatment combination, p3r2 resulted in higher OC content (0.91%) and was on par with p2r3. Available P content of post experiment soil was found to higher in p2r2. The treatment combination, p2r3 resulted in higher gross return, net return (₹ 97070 ha-1) and B: C ratio (2.20) and it was followed by p2r2. The study demonstrated that seed priming with liquid organic manures— particularly vermiwash at 5 and 3 per cent concentrations—significantly enhanced germination, seedling vigour, and early growth parameters in rice. Both seed priming and weed management practices had a substantial impact on crop growth, physiological traits, nutrient uptake, yield, weed suppression, and economic returns. Among all treatments, seed priming with 5% vermiwash combined with green leaf manuring using Gliricidia maculata (10 t ha⁻¹), followed by wheel hoe weeding at 30 and 45 DAS, emerged as the most effective strategy for maximizing yield and profitability under aerobic rice cultivation.