DSpace 8

DSpace is the world leading open source repository platform that enables organisations to:

  • easily ingest documents, audio, video, datasets and their corresponding Dublin Core metadata
  • open up this content to local and global audiences, thanks to the OAI-PMH interface and Google Scholar optimizations
  • issue permanent urls and trustworthy identifiers, including optional integrations with handle.net and DataCite DOI

Join an international community of leading institutions using DSpace.

The test user accounts below have their password set to the name of this software in lowercase.

  • Demo Site Administrator = dspacedemo+admin@gmail.com
  • Demo Community Administrator = dspacedemo+commadmin@gmail.com
  • Demo Collection Administrator = dspacedemo+colladmin@gmail.com
  • Demo Submitter = dspacedemo+submit@gmail.com
Photo by @inspiredimages
 

Communities in DSpace

Select a community to browse its collections.

Recent Submissions

No Thumbnail Available
Item
Sensor based nutrient management in Tomato (Solanum lycopersicum)
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2026-02-09) Mayoora Shaji; Rekh, V R Nair
The study entitled ‘Sensor based nutrient management in tomato (Solanum lycopersicum)’ has been carried out at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, during 2023-2025. The objective of the study was to compare soil test values obtained through different sensors and laboratory analysis; Yield assessment to analyse the efficiency of the sensor using tomato as the test crop. The study was carried out in two parts. The first part focused on comparing nutrient analysis across different cropping systems using sensor-based measurements and conventional laboratory analysis. Surface soil samples (0-15 cm) were collected from four land-use systems, , vegetable-based cropping system, coconut-based mixed farming, homestead farming, and fallow land within AEU 8. Five samples were collected from each system using the standard soil sampling procedure, with one composite sample taken for every 20 cents of area. Two portable sensors were deployed to measure soil nutrients at each location. Sensor 1 (Modbus) provides primary nutrient estimates (N, P, K) using an electrical-conductivity-based sensing principle. Sensor 2 (NutRE) measures primary (N, P, K), secondary nutrients (Ca, Mg, S), and selected micronutrients (Fe, Zn, Cu) through an ion-sensing mechanism, with further technical details withheld due to a pending patent. For field measurements, six random sampling points were selected within each 20-cent area, matching the locations used for conventional soil sampling. Modbus readings were taken at two points and averaged, and this procedure was repeated across the remaining 3-6 randomly selected spots within each location. The same sampling approach was applied for the NutRE sensor. The mean nutrient values obtained from both sensors were then compared with corresponding laboratory measurements. The Modbus sensor (Sensor 1) showed no significant difference (p > 0.05) for P under all land-use systems and across all computed mean levels (M2—M6), indicating close agreement with laboratory values for these parameters. However, N and K showed significant deviation (p = 0.00), suggesting the need for calibration for these nutrients. In contrast, the NutRE sensor demonstrated non-significant differences (p > 0.05) for all measured nutrients (N, P, K, Ca, Mg, S, Fe, Zn, Cu) across all land-use systems and mean levels, reflecting strong alignment with laboratory analysis. Variation in the number of readings used for mean calculation (M2—M6) did not significantly influence sensor accuracy for either sensor. Therefore, adopting the minimum mean level (M2) was adequate for accurate nutrient estimation across all systems, improving operational efficiency by reducing sampling time and field effort. The second part involved a field experiment that assessed sensor efficiency through tomato (cv.Anagha) yield evaluation, where the performance of both sensors was compared against soil test-based nutrient management. The experiment consisted of five treatments: T: (STB) — Split application of N P K as per soil test data (laboratory analysis). Tz (MDS-Nb) — Split application of N P K as per sensor | reading at 15 days interval up to beginning of harvest (Modbus sensor without basal). Ts (NutRE-Nb) — Split application of N P K as per sensor 2 reading at 15 days interval up to beginning of harvest (NutRE sensor without basal). Ts (MDS-B) — NPK application as basal dose based on Ist sensor data and further split up at 15 days interval (Modbus sensor with basal). Ts (NutRE-B) — NPK application as basal dose based on 2nd sensor data and further split up at 15 days interval (NutRE sensor with basal). Biometric observations revealed, at harvest, T: recorded the highest plant height (61.17 cm), while Ts produced a significantly greater number of branches (4.81). Leaf Area Index was highest under T; (2.59). With respect to yield attributes, T: produced a significantly greater number of fruits per plant (34.81), and the maximum fruit yield per plant (1.10 kg) while Ts (35.65g) produced highest fruit weight. Post-harvest soil analysis revealed significantly higher available N (210.12 kg ha‘) and K (207.20 kg ha"') under Ti, whereas Ts recorded the highest available P (85.20 kg ha‘). Plant nutrient analysis conducted at 15 and 30 DAT showed that Ts consistently recorded maximum NPK content during early crop growth, while at harvest, N and K contents were highest in T, and P content was highest in Ts. A similar trend was observed in nutrient uptake. Economic analysis showed that Ti yielded the highest gross income (Rs. 720,254.80) and B:C ratio (1.81), closely followed by Ts. T-test and Absolute Error Percentage (AEP) results showed that NutRE sensor accurately estimated all nutrients, with non-significant differences from laboratory values. Modbus sensor was reliable for phosphorus, while nitrogen and potassium required calibration to match laboratory standards. Field experiments revealed that soil test-based nutrient management T: (STB) achieved the highest yield, which was statistically comparable to the calibrated NutRE-based treatment Ts (NutRE-B). These results confirm that sensor-based nutrient management becomes effective only when supported by proper calibration and the inclusion of basal nutrient doses.
No Thumbnail Available
Item
Influence of fundamental motives on retention of certified organic farmers in Kerala agricultural development society, Thodupuzha
(College of Co-operation, Banking and Management, Vellanikkara, 2026-09-12) Devika, C G; Biju Thomas Muttath
No Thumbnail Available
Item
Awareness and adoption of farm mechanisation by rice farmers in Palakkad district
(College of Co-operation,Banking & Management, Vellanikkara, 2023-09-13) Thomson James; Divya Vijayan
No Thumbnail Available
Item
Etiology and management of leaf spot disease of arecanut in northern Kerala By: Bhavana, A S
(Department of Plant Pathology, College of Agriculture, Padannakkad, 2026-02-19) Bhavana, A S; Sajeesh, P K
The study entitled “Etiology and management of leaf spot disease of arecanut in Northern Kerala” was carried out in the Department of Plant Pathology, College of Agriculture, Padannakkad during 2023-2025 with the objective of etiology of the fungal pathogen/s associated with the leafspot disease of arecanut and to formulate management strategies against the disease. A purposive sampling survey was conducted in four AEUs of Kasaragod and Kannur districts to collect infected and healthy leaf of arecanut leaf spot disease affected palms samples. The fungi associated with the leaf spot symptoms were isolated and characterised. Pathogenicity tests revealed that twelve isolates were pathogenic, producing symptoms within 12–15 days after inoculation. These twelve pathogenic isolates were subsequently sent to the Rajiv Gandhi Centre for Biotechnology (RGCB), Thiruvananthapuram, for molecular characterization. Among the six isolates three isolates showed high similarity with Colletotrichum arecicola which is reported for the first time on arecanut in India. The contents of nitrogen (N), potassium (K), calcium (Ca), magnesium (Mg), and boron (B) were analysed in both healthy and diseased leaf samples collected from various locations and AEUs. A total set of healthy and diseased leaf samples were analysed using standard protocols. It was found that K level was consistently higher in healthy samples compared to diseased ones, indicating the role of K in enhancing disease resistance. Nitrogen and magnesium showed variable patterns depending on the AEU and did not follow a uniform trend. Calcium content was generally higher in healthy leaves, except in the leaves collected from AEU 13. Boron levels tended to be higher in diseased leaves suggesting a possible stress induced accumulation. Phylloplane microorganisms were isolated from the healthy arecanut leaves. These were evaluated for antagonism towards Colletotrichum arecicola using dual culture technique. Among them, two Trichoderma- like fungal isolates and one-gram negative bacterial isolate exhibited strong inhibition of the predominant pathogen C. arecicola. Under in vitro evaluation of fungicides against C. arecicola by poison food technique, mancozeb (75WP) at 0.2%, propiconazole (25EC) at 0.2% and carbendazim 12% + mancozeb 63% (75 WP) at 0.2% exhibited high inhibition (100%). These three fungicides, along with the antagonists selected from phylloplane used for in vivo evaluation against the disease. Fungicides and antagonists were applied one week after pathogen inoculation on leaves. After 15 days of fungicide application, propiconazole (25 EC) at 0.2% and carbendazim 12% + mancozeb 63% (75 WP) at 0.2% were found effective against arecanut leaf spot. The study identified as C. arecicola is the major cause of arecanut leaf spot in Northern Kerala, and it reported for the first time on arecanut in India. Nutrient analysis showed that higher potassium levels were associated with healthier leaves. Among the management options tested, propiconazole (25 EC) at 0.2% and carbendazim 12% + mancozeb 63% (75 WP) at 0.2% were the most effective in reducing disease severity. The findings are helped to learn more about the etiology of the leaf spot disease and in developing improved fungicide and fertilizer schedules for managing arecanut leaf spot disease.
No Thumbnail Available
Item
Characterization of pathogens causing canker and dieback diseases in moringa (Moringa oleifera Lam.)
(Department of Plant Pathology, College of Agriculture, Vellanikkara, 2026-02-06) Adithya Sreekumar; Anju, C
Canker and dieback are increasingly recognized as major constraints in moringa cultivation, despite the crop’s well-known resilience and rich phytochemical defence. Field observations across Kerala have indicated a rising incidence of these diseases affecting young and mature plants alike, yet systematic documentation of the causal pathogens and their interaction with the host remains limited. The present investigation was undertaken to identify, characterize and evaluate the pathogenic potential of fungi associated with canker and dieback diseases of moringa, and further to assess host biochemical responses at critical developmental stages. The study was carried out in the Department of Plant Pathology, College of Agriculture, Vellanikkara, from 2023 to 2025. A purposive survey of moringa-growing homesteads and nurseries in Thrissur (AEU 10) and Ernakulam (AEU 12) districts yielded a total of 65 diseased samples from which 77 fungal isolates were obtained, comprising 50 from canker-affected tissues and 27 from dieback samples. Disease intensity varied among locations, with the highest PD1 for canker recorded at Kolazhy (AEU 10) (89.28 %), while the maximum PD1 for dieback was recorded at Kothamangalam (AEU 12) (76 %). Several samples yielded multiple isolates, indicating the coexistence of distinct fungal species within the same lesion. Isolates were purified using hyphal-tip culture and maintained on PDA for further studies. Canker symptoms under natural conditions included superficial bark cracking, pale-yellow to light-brown sunken or flat lesions and localized necrosis. Dieback symptoms, on the other hand, were characterized by progressive twig/branch drying, extensive cortical discoloration and the appearance of black, pinhead-like pycnidial structures on severely affected tissues. Pathogenicity testing conducted under rain-shelter conditions confirmed the ability of all tested isolates to reproduce disease symptoms on moringa, fulfilling Koch’s postulates. Symptom development varied markedly among isolates, indicating a wide spectrum of virulence. Cultural and morphological characterization of the isolates revealed considerable diversity in colony growth, pigmentation, sporulation and microscopic traits. Isolates associated with canker generally produced fast-spreading, cottony to fluffy mycelium with pink, white, or grey colouration, while dieback-associated isolates commonly showed dark, melanised mycelium with abundant pycnidial formation. Molecular characterization using ITS, TEF-1α and RPB2 gene regions confirmed the presence of multiple pathogenic species on moringa. Canker symptoms were associated with Fusarium irregulare, F. citri, Nectria sp. and Lasiodiplodia theobromae, whereas dieback was predominantly caused by L. theobromae, Curvularia sp. and Diaporthe batatas. This represents the first comprehensive documentation of the canker-dieback pathogen complex occurring on moringa in Kerala. Extracellular cellulases and pectinases production was evaluated using substrate-amended media. All isolates exhibited measurable cellulolytic and pectinolytic activity. Among the 77 tested isolates, several, including Fusarium sp. (AIS5), Fusarium sp. (VLD2), Lasiodiplodia sp. (VLD1), Fusarium sp. (MAD), Curvularia sp. (MLD2) and Curvularia sp. (AVD3), produced large hydrolytic zones (mm) within just 2-3 days, reflecting a strong enzymatic activity. Statistical analysis 2 revealed a highly significant positive correlation between lesion size and enzyme activity, indicating that both cellulase and pectinase secretion are strongly linked to virulence expression. Two highly virulent isolates, L. theobromae, CHS2 (canker) and L. theobromae, TRD1 (dieback), were selected for biochemical assays. Host response was examined at five principal developmental stages: leaf, shoot, flowering, fruiting and senescence. CHS2 produced small, slowly enlarging lesions across all developmental stages, beginning as light-brown or pale-yellow spots (0.1-0.2 cm) that expanded slowly and developed into ovoid to spindle-shaped forms with mild cracking by day five. In contrast, TRD1 generated faster-expanding lesions even in early stages, initial pale brown patches (0.1-0.2 cm) rapidly enlarged (up to 2.5 cm by day 5) and frequently coalesced, progressing from pale yellow or water-soaked patches to darker brown or black lesions. Overall, CHS2 showed slower, stage-dependent lesion expansion, whereas TRD1 exhibited rapid, aggressive lesion development across all growth stages. Total phenolic content varied widely among growth stages and according to pathogens. In the flower development stage, inoculated plants accumulated substantially higher phenols than controls from one day after pathogen inoculation, indicating a pronounced early defence response. Conversely, in leaf and fruit development stages, phenol levels in inoculated plants dropped significantly below those of the corresponding controls, suggesting growth stage-specific phenol biosynthesis in response to pathogen infection. During senescence, phenol levels remained low across TRD1 inoculated treatment, reflecting a natural decline in defence capacity. Flavonoid content showed a transient decline at one to two days post inoculation across most developmental stages. This was followed by a clear rebound on days three and five, especially in the leaf and shoot development stages, reflecting induced defence activation. In the leaf development stage inoculated with CHS2, flavonoids increased markedly by day five (22.85 mg QE g⁻¹; ~26% above control). TRD1-inoculated tissues displayed a similar pattern of early reduction followed by strong accumulation of flavonoids from day three. Overall, the study establishes that canker and dieback in moringa are caused by a diverse assemblage of fungal pathogens exhibiting wide variability in virulence and extracellular enzyme activity. The findings highlight the central role of cell-wall degrading enzymes in facilitating tissue colonization and disease progression. Moreover, phenolic and flavonoid profiling across growth stages reveals that moringa exhibits a highly stage-dependent defence strategy, with stronger biochemical activation during early vegetative growth and flowering stages and weaker responses during fruiting and senescence. These insights form an essential foundation for developing stage-specific disease management strategies and for future exploration of host resistance mechanisms in moringa.