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Comparative study on infrared radiation and hot air convective drying of coconut: Effect on oil quality features
(2024) R. Pandiselvam; Sneha Davison; M.R. Manikantan; Anjitha Jacob; S.V. Ramesh; S h a m e e n a Be e g u m , P.P.
Appropriately dried coconut kernel, or copra, is imperative for oil production to ensure consistent quality, taste, aroma, and nutritional properties of the resultant coconut oil. This research assesses the effects of different drying techniques—hot air drying (HAD), infrared drying (ID), and infrared-assisted hot air drying (IAHAD)—on the quality profile of coconut oil extracted from copra. Coconut kernels were subjected to radiation and convective hot-air drying methods at varying temperatures (50 °C, 60 °C, and 70 °C). The fresh oil sample extracted from copra using different drying techniques exhibited zero peroxide value, indicating high quality. Among the methods, IAHAD at 60 °C was remarkable for producing the highest-grade copra, resulting in superior quality oil with exceptional preservation of essential nutrients. The physical and biochemical properties of the coconut oil produced using IAHAD at 60 °C included specific gravity, refractive index, moisture content, antioxidant capacity, and total phenolic content, all indicating enhanced oil quality.
Development, evaluation, and optimization of portable pyrolysis system for the production of biochar from tender coconut husk
(2024) R. Pandiselvam; Athira Shaji; S. V. Ramesh; Sudharshana Sathyanath; M. R. Manikantan; A. C. Mathew
Tender coconut husk (TCH) is a prominent part of coconut fruit, and it is discarded after consumption of tender coconut water. TCH is made of fibers that comprise lignin (30–42%) and cellulose (54–65%) and also contains traces of tannin and potassium. In this study, development of most feasible and adaptable method for production of biochar from TCH is reported. The method opted for the production of biochar is pyrolysis, and temperature of pyrolysis has a direct correlation with the characteristics of resultant biochar. The main parameters investigated are the size of the reactor, type of fuel, and positioning of the drum. Biochemical parameters of biochar such as moisture content, ash content, pH and electrical conductivity, and total nitrogen content of the product were studied. The results reveal that sample collected from the upper layer of the large-sized reactor kept in upright position and using mature coconut husk as a fuel for biochar production was found to be the best considering the yield and physicochemical properties.
Physicochemical properties of coconut inflorescence sap (neera) under double wall open heating system
(2024) R. Pandiselvam; Sudharshana Sathyanath; M. R. Manikantan; S. V. Ramesh; S h a m e e n a Be e g u m , P.P.; Hebbar, K.B
Utilization of plant sap-derived sugars and syrups, such as palm sugar, birch syrup, maple syrup, and agave syrup, provides versatile alternatives to conventional sweeteners like cane sugar and high-fructose corn syrup, thereby enriching culinary options and catering to diverse consumer preferences. One noteworthy product derived from coconut palm sap is neera, a traditional beverage celebrated for its natural sugars, vitamins, minerals, and bioactive compounds. Its nutritional value and cultural significance make it a cherished component of local diets. It is nutritionally important due to its natural sugars (sucrose, glucose, and fructose), rich in vitamins and minerals (potassium, magnesium, zinc, and iron). The focus of this study is to comprehend the biochemical changes that occur during the conversion of neera into sugar using an open double-jacket cooker. The process entails meticulous monitoring of various parameters, including total soluble solids (TSS), pH levels, total sugar content, reducing sugar content, total phenol content (TPC), antioxidant activity (measured by DPPH and FRAP assays), and ascorbic acid concentration. Throughout the 3 h heating process, samples are collected at 30 min intervals to track the changes in biochemical composition. Continuous stirring and precise temperature control ensure uniform heat transfer and accurate results. The findings reveal significant alterations in biochemical composition, with notable increases observed in TPC and antioxidant activity, possibly attributed to the Maillard reaction. The conversion from neera to coconut sugar yields a range of compositions suitable for various culinary applications, presenting opportunities for entrepreneurship and the development of value-added products. This not only enhances market competitiveness but also fosters economic growth in the food sector.
Impact of Slice Thickness and Baking Temperature on the Physicochemical Quality and Nutritional Properties of Newly Developed Baked Coconut Chips
(2024) R. Pandiselvam; Rupa Krishnan; M. R. Manikantan; Anjitha Jacob; S. V. Ramesh; S h a m e e n a Be e g u m , P.P.
Due to rising health concerns, consumers are increasingly inclined toward reduced-fat products, which have driven the need for nutritious alternatives through modifications in recipes and production processes. Despite the growing popularity of coconut-based products, there is limited research on baked coconut chips, particularly regarding the effects of baking temperatures and product thicknesses. This study addresses this gap by developing baked coconut chips samples (BCSs) as a healthier alternative to traditional fried chips. Baking experiments were conducted at temperatures of 140°C, 160°C, and 180°C, with 160°C identified as optimal for balancing processing time and product quality. The study also compared baked coconut chips with those that were dried and then baked (dried baked coconut chips samples [DBCS]). Among the trials, the 0.5-mm-thick coconut chips baked at 160°C exhibited favorable sensory attributes and notable biochemical properties, including 3.13% moisture content, 1.13% ash, 40.49% fat, and significant antioxidant activity.
Comparative analysis of biochemical composition of fried coconut chips: influence of thickness and oil type on nutritional attributes
(2024) R. Pandiselvam; Rupa Krishnan; M. R. Manikantan; Anjitha Jacob; S. V. Ramesh; S h a m e e n a Be e g u m , P.P.
In recent years, there has been a noticeable rise in the importance of snack items in diets, particularly among children and adolescents who enjoy them socially with friends. Chips, commonly produced through frying, have garnered significant popularity. This study aimed to assess the quality of fried coconut chips of thickness 0.5 mm and 1.4 mm, made using both sunflower oil and coconut oil. Deep frying was conducted at 160 °C for both types of oil. The findings indicated that coconut oil-fried chips, regardless of thickness, exhibited superior sensory attributes (i.e. appearance, colour, crispiness and flavour). All sensory attributes (except appearance) were rated the highest for coconut oil fried chips. The biochemical properties of chips fried in both oils were largely similar, yet coconut oil-fried chips displayed slightly better characteristics compared to their counterparts. For instance, the 0.5 mm thick coconut oil-fried chips were noted for their improved protein content and fat content, leading to a higher overall acceptability of the 0.5 mm thickness.
Comparison of engineering properties of organic and inorganiccoconut: Implications on the design of coir fiber extractionmachine
(2024) Ravi Pandiselvam; M. R. Manikantan; P. Subramanian; Anandu Chandra Khanashyam; M. Anjaly Shanker; R. Surekha; Alka Gupta
Coconut husk is widely used as a source of natural fibers in the tropics. Dehusking and fiber extraction are some of the important unit operations in coir manufacturing. For the development of an efficient and economically viable fiber extraction machine, the engineering properties of conventional and organically grown coconuts were evaluated. Selected engineering properties of whole coconut were investigated. The average true density and bulk density were in the range of 414.63 ± 111.85 to 529.28 ± 123.02 and 161.66 ± 24.41 to 212.23 ± 18.96 kg/m3, respectively. Along with whole coconuts, engineering properties of husk (weight, moisture content, and husk thickness), shell (weight, thickness, bulk density, and moisture content), and kernel parameters (weight, thickness, and moisture content) were also evaluated. The application of organic treatment (T4) exhibited substantial impacts, leading to a higher coconut weight (1.354 kg) as compared to conventional practices (T5), and increased dimensions (158.599 mm diameter and 205.000 mm height) and improved bulk density (190.97 kg/m3) in comparison to other organic treatments. In deshelled coconuts, T4 showcased a higher shell weight (175.667 g) and shell thickness (4.767 mm). The kernel parameters of T4 displayed enhancements, featuring a kernel weight of 314.334 g and a thickness of 11.774 mm. Although the study could not find any correlation between the farming practices and engineering characteristics of coconut fruit, the data presented herein could be utilized for the design and improvisation of efficient fiber extraction machines.
Transformative effects of infrared-assisted hot air drying on neera syrup concentrated coconut flakes: a comprehensive evaluation of physical properties, composition analysis and antioxidant profiles
(2024) Ravi Pandiselvam; M. Mahamutha Thazneem; Manikantan, M.R; Anjitha Jacob; S. V. Ramesh; S h a m e e n a Be e g u m , P.P.
The objective of this study is to develop coconut flakes that are readily consumable, using various drying techniques following osmotic dehydration in neera syrup concentrate (50ºBrix). A novel methodology and process have been established to create these coconut flakes, offering a distinct production approach. The infusion of neera syrup enhances taste, flavor, and color and augments the product’s nutritional content. Through drying experiments at 55, 65, and 75 ºC temperatures, the study seeks to identify the most suitable drying method and temperature. Analysis of the bioactive profile revealed that coconut flakes dried at 65 ℃ using infrared-assisted hot air dehydration (IRHAD) demonstrated exceptional nutritional attributes. These include a Hausner ratio of 1.04, Carr’s index of 4.22, rehydration ratio of 2.37, hygroscopicity of 1.68%, bulk density of 0.552 g/mL, tapped density of 0.610 g/mL, protein content of 3.92%, carbohydrate content of 33.86%, fat content of 34.29%, ash content of 1.92%, total phenolic content of 105.38 mg GA/100 g, DPPH activity of 88.81%, and FRAP of 0.00893 mg TE/100 g. Further investigations are warranted to assess the shelf life of coconut flakes, the influence of various packaging materials, and delve deeper into the biochemical properties of the dried samples.
Development and characterization of gelatinized starch doped microcellulose paper from tender coconut (Cocos nucifera L) husk
(2024) R. Pandiselvam; M.P. Harikrishnan; Anandu Chandra Khanashyam; M. Basil; M. Anirudh; M.R. Manikantan; Anjineyulu Kothakota
Cellulose-starch based composite papers are could be used as packaging materials due to their biodegradable and renewable properties. In this study, biodegradable composite paper were developed from tender coconut husk with starch as an additive. Potato and corn starch were added to the matrix at a ratio of 5%, 10% and 15% and were evaluated for the mechanical, physical, and structural properties as well as the biodegradability of the biocomposite paper. The tensile strength and the elongation percentage of the developed biocomposite paper varied from 12.45 ± 1.69 MPa to 9.52 ± 4.30 MPa and 9.76 ± 0.99% to 15.52 ± 3.27% respectively. The results indicate a decreasing trend in tensile strength with increasing starch concentration, attributed to reduced hydrogen bonding density. Moisture content analysis shows no significant difference between starch types. The composition of the paper was analyzed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The outcomes demonstrated the existence of robust interactions between the hydroxyl groups of starch and cellulose of coconut husk matrix. Moreover, the material showed a degradation rate of approximately 70% within a 20-day period, demonstrating its suitability for the production of biodegradable material. This study suggests that tender coconut husk is a promising material for the production of paper intended for packaging applications.
Infrared-aided hot-air drying of coconut: Impact on drying kinetics and quality metrics
(2024) R. Pandiselvam; Sneha Davison; M. R. Manikantan; G. Jeevarathinam; Anjitha Jacob; S. V. Ramesh; P. P. Shameena Beegum
This study explored various drying techniques and temperatures to analyze their effects on the drying kinetics and quality of copra. The initial moisture content of coconut kernels was 50%–55% (w.b.), which decreased to 6%–8% (w.b.) as a result of the drying process. This study focuses on evaluating the individual and hybrid effects of infrared drying (IRD) and hot-air drying (HAD) techniques to enhance the quality of copra. Three drying methods were used: IRD, HAD, and infrared-assisted hot-air drying (IRAHAD). Coconut pieces were subjected to different drying temperatures (50, 60, and 70 C) with a constant air speed of 2 m/s. Optimal results were achieved by employing the IRAHAD method at 60 C, preserving a crucial fat content of 68.4% essential for increased extraction of oil from copra and comparatively high drying rates. In particular, the drying rates in IRAHAD were twice as high as those in IRD and HAD. At a drying temperature of 60 C, the logarithmic model and the diffusion approximation model were deemed the best fit for HAD and IRAHAD, respectively.
Evaluation of unmanned aerial vehicle for effective spraying application in coconut plantations
(2024) R. Pandiselvam; Daliyamol; Syed Imran S; Vinayaka Hegde; M. Sujithra; P.S. Prathibha; V.H. Prathibha; K.B. Hebba
Unmanned aerial vehicle (UAV) pesticide application in recent years owing to its importance such as time saving, reduction in human drudgery and also reduction in pesticides application rate. UAV has a great potential to address the problem involved in manual chemicals spraying in tall crops like coconut plantation where at present operation performed by manual climbing involves lots of drudgery and life risk. The current study aimed to understand the most influencing spraying parameters, such as spray height and spray time of the UAV sprayer on droplet characteristics such as spray droplet size, spray coverage and spray deposition at different layers (spindle, middle and bottom) of coconut tree canopy. The selected spray height (1, 2 and 3 m) and spray time (5, 8 and 11 s) significantly affects (p < 0.05) the droplet size (μm), spray coverage (%) and spray deposition (μl cm−2). In spray droplet size, the treatment T4, T5, T7 and T8 were recorded recommended droplet size of 50–400 μm in all layer of the coconut tree canopy. In spray coverage, the nearest value for recommended spray coverage of 10–20 % was observed for T1 and T5 treatment in all layer of the coconut tree canopy. The maximum penetration efficiency of 34.41 % had achieved at spray height of 2m and spray time of 8s (treatment T5). Based on performance of selected parameter, the spray height of 2 m and spray time of 8 s (treatment T5) was found best for spraying operation using UAV in coconut tree. The results showed the performance of the UAV offers best alternative for spraying operation on coconut tree and also this system will drastically reduce application time, labour requirement and improved the safety of coconut farmers.
Colletotrichum kahawae subsp. cigarro causing leaf spot disease on arecanut, Areca catechu L. in India: A first report
(2024) R. Thava Prakasa Pandian; Shivaji Hausrao Thube; Bhavishya; Merin babu; H. Rajashekara; T.N. Madhu; Diwakar, Y.; P. Santhoshkumar; B.J. Nirmalkumar; Balanagouda Patil; V. Hegde
Arecanut is a prominent cash crop in India, known for its potential to significantly boost per capita income. The presence of fungal diseases poses a significant constraint to arecanut cultivation. In October 2019, a severe outbreak of leaf spot disease with 90°% disease incidence was recorded in the farmer's arecanut gardens from Kalasa hobli, Chikkamangaluru, Karnataka, India. Leaf spot symptoms started as small, irregular, light-dark brown spots (3–10 mm in diameter) with a yellow halo on the leaf lamina, which later coalesced to form larger necrotic lesions and a blighted appearance. The symptoms were also observed on leaf sheaths and nuts. In the present study, we identified and characterized the pathogen causing leaf spot disease using cultural, morphological, molecular characterization using multi-gene phylogeny, and pathogenicity assays. Microscopic, and molecular identification of CPCRICkc7G isolate retrieved from the leaf spot infected sample established the association of Colletotrichum kahawae subsp. cigarro as the causal agent. Pathogenicity assays confirmed the Koch's postulate by reproducing the field observed symptoms. To best of our knowledge, this confirms the first report of C. kahawae subsp. cigarro causing leaf spot disease on arecanut in India. The findings from this current study play a pivotal role in enhancing the knowledge of arecanut diseases in India, and lay an essential foundation for devising effective disease management approaches to curtail the disease spread.
From the discovery of a novel arepavirus in diseased arecanut palms (Areca catechu L.) in India to the identification of known and novel arepaviruses in bee and plant transcriptomes through data-mining
(2024) R. Thava Prakasa Pandian; Bhavishya; V. Kavi Sidharthan; M.K. Rajesh; Merin Babu; Susheel Kumar Sharma; B.J. Nirmal Kumar; M. Chaithra; Vinayaka Hegde
Arecanut palm is a commercially important plantation crop valued for its nut. In this investigation, we report the discovery of a putative novel arepavirus, named areca palm necrotic ringspot virus 2 (ANRSV2), in necrotic ringspot diseased areca palms in Bantwal, Dakshina Kannada, Karnataka, India through RNA-sequencing and transmission electron microscopy. Further, the presence of ANRSV2 in the diseased samples was confirmed through reverse transcriptase-polymerase chain reaction assays. In addition, by mining public domain transcriptome data for arepaviral sequences, we identified a putative novel arepavirus in Psychotria rubra, a non-palm host. We recovered the genome sequences of the areca palm necrotic ringspot virus in honey bees, tomato, Onobrychis viciifolia, and Rhamnus heterophylla. These findings broaden our comprehension of arepaviral diversity and host range, and suggest an intriguing possibility of pollen-mediated arepaviral transmission that necessitates empirical validation. Further studies are needed to understand the biology of identified putative novel arepaviruses.
Adoption level of improved dairy farming practices by resource poor dairy farm households
(2024) Saurabh Pandey; Kuppusamy Ponnusamy; Keesam manasa
The level of adoption of improved dairy farming practices would reveal the interest and enthusiasm of any individual farmer. A study was carried out in Haryana to determine the degree to which the chosen resource poor dairy farmers have adopted improved dairy farming practices. The purpose of the study was to ascertain how resource-poor dairy farmers were implementing new techniques. It was established what degree of acceptance the four main facets of dairy farming-breeding, feeding, healthcare, and management practices-had by resource-poor dairy producers. In the years 2021-2022, the research was carried out in the districts of Karnal, Jind, and Jhajhar in the state of Haryana, which correspond to three distinct agroclimatic zones. This was followed by selection of cluster of villages in each district with the predominance of resource poor dairy households and then 40 respondents randomly from each cluster. Thus, study constituted a sample size of 120 respondents. Data were collected using structured interview schedule which was later analysed by using frequency, percentage and regression. The findings revealed that majority of the respondents had medium level of adoption of breeding practices (54.17%), feeding practices (60.00%) and healthcare practices (57.50%). Majority of respondents (65.00%) possessed medium level of adoption of management practices too. Most of respondents (47.50%) belonged to medium level of overall adoption of improved dairy farming practices. About 54.6 per cent variance on dependent variable is due to the independent variables taken for the study. This implies the need for undertaking intensive education of resource poor farmers along with facilitation of critical inputs for profitable dairy farming.
Coconut husk: A sustainable solution for eco-friendly packaging applications
(2024) Azime Özkan Karabacak; Özge Süfer; Ravi Pandiselvam
This paper explores the use of coconut husk as an eco-friendly alternative for packaging. It details the composition, extraction, and processing techniques of coconut husk, emphasizing its abundance and sustainable sourcing methods. Key findings include the use of polyphenols extracted from young coconuts, achieving an 81% reduction in CO2 gas permeability and a 79% reduction in oxygen transmittance rate, demonstrating significant antimicrobial properties. The study highlights the creation of eco-friendly paper from coconut husk fibers and the development of bioplastics. Biocomposite films derived from coconut coir showed enhanced tensile strength and elongation, outperforming starch-based films. Environmental benefits include waste reduction and sustainable resource utilization, with the inclusion of 3% coir cellulose nanofibers in composite films notably improving tensile strength, elongation at break, and thermal stability. To sum up, this document highlights the importance of adopting sustainable materials in packaging and explores exciting possibilities for future studies, advancements in technology, and the widespread adoption of packaging solutions derived from coconut husks. This emphasizes the potential to drive a more environmentally friendly, sustainable, and eco-conscious packaging sector.
Sulfate transport and metabolism: strategies to improve the seed protein quality
(2024) C R Nagesh; Rama Prashat G; Suneha Goswami; C Bharadwaj; Shelly Praveen; S. V. Ramesh; T Vinutha
Sulfur-containing amino acids (SAA), namely methionine, and cysteine are crucial essential amino acids (EAA) considering the dietary requirements of humans and animals. However, a few crop plants, especially legumes, are characterized with suboptimal levels of these EAA thereby limiting their nutritive value. Hence, improved comprehension of the mechanistic perspective of sulfur transport and assimilation into storage reserve, seed storage protein (SSP), is imperative. Efforts to augment the level of SAA in seed storage protein form an integral component of strategies to balance nutritive quality and quantity. In this review, we highlight the emerging trends in the sulfur biofortification approaches namely transgenics, genetic and molecular breeding, and proteomic rebalancing with sulfur nutrition. The transgenic ‘push and pull strategy’ could enhance sulfur capture and storage by expressing genes that function as efficient transporters, sulfate assimilatory enzymes, sulfur-rich foreign protein sinks, or by suppressing catabolic enzymes. Modern molecular breeding approaches that adopt high throughput screening strategies and machine learning algorithms are invaluable in identifying candidate genes and alleles associated with SAA content and developing improved crop varieties. Sulfur is an essential plant nutrient and its optimal uptake is crucial for seed sulfur metabolism, thereby affecting seed quality and yields through proteomic rebalance between sulfur-rich and sulfur-poor seed storage proteins.
Assessment of the spatial distribution and identification of potential risk areas for the sterility mosaic disease of pigeonpea (Cajanus cajan L. Huth) in Southern India
(2024) Mediga, K.R.; Sunkad, G; Shil, S; Kulkarni, S; Patil, B.; Sharathchandran, U.S.; Ashwini, P.; Sharma, M.
Sterility mosaic disease (SMD) is an emerging biotic risk to the cultivation of pigeonpea throughout the Indian subcontinent. The prevalence and distribution of SMD documented from diverse agro-climatic zones are still poorly known. In this investigation, we determined the spatial distribution of SMD covering major pigeonpea-growing states of Southern India namely, Karnataka, Telangana, Tamil Nadu, Maharashtra, and Andhra Pradesh by considering 2 years of exploratory survey data. Geospatial approaches were employed to determine the SMD incidence levels at unvisited locations using neighboring observations. The results indicated enormous variability in disease incidence ranging from 0 to 82.64% and 0 to 36.84%, respectively, in Kharif 2021–22 and 2022–23 in pigeonpea-growing states. Spatial autocorrelation analysis and Ripley’s K function established the presence of average clustering over sampling locations. Two main clusters were identified via agglomerative hierarchical cluster analysis. From the Local Moran’s I spatial autocorrelation (LISA) analysis, most of the districts were clustered together at (I<0). From the p-values, Bidar and Krishnagiri districts recorded the highest spatial dependence, while the remaining districts recorded medium spatial dependence (p < 0.05). Based on kriging, the Chittoor district of Andhra Pradesh, Medak and Ranga Reddy districts of Telangana, Bijapur district of Karnataka, and Latur district in Maharashtra states were found to be vulnerable to SMD occurrence in the future. The Matern and Spherical models were shown to be the best of the several semivariogram experimental models tested for spatial patterns of SMD incidence, from which OK and IK maps were created. Based on the interpolation results, the potential SMD hotspots/risk areas were most prominent in Telangana, Andhra Pradesh, Karnataka, and Tamil Nadu states. These identified hotspots for SMD revealed high levels of disease probability rates (>25%) above the threshold level and must be closely monitored to restrict and minimize further disease spread across the studied areas in Southern India. In pigeonpea, this is the first study in India that attempted to understand the spatial pattern of SMD using geostatistical methodologies. The results of the study will aid in the design and dissemination of specific management practices and curb the further spread of SMD.
Influence of mineral nutrition on the soil health and productivity of coconut palms (cocos nucifera l.) in tropical land use systems
(2024) J. Mathew; A. A. Haris; S. Indhuja; K. M. Nair; V. Krishnakumar; Ravi Bhat; S. Shil
Perennial plantation crops, such as coconut trees require the systematic addition of nutrients for sustained growth and productivity. This study aimed to understand plant and soil nutrient dynamics, root health and soil biological properties upon addition of specific nutrients in tropical land use systems. Field experiments in randomised block design were conducted in Agro-Ecological Unit-3 (AEU-3) and Agro-Ecological Unit-9 (AEU-9) from 2014 to 2020. Treatments were T1 (site-specific nutrient management practices (SSNM), T2 (SSNM without sodium chloride); T3 (SSNM without gypsum); T4 (SSNM along with the 50 g microbial formulation Kera Probio); T5 (Farming practice without any amendments or nutrients). Root health parameters, cumulative nut yield and nutrient dynamics in soil and leaf samples were estimated at the beginning and the end of the study. Systematic provision of all the essential nutrients resulted in significant increase content of N (1.39%), P (0.164%), K (1.71%), Ca (0.406%) and Mg (0.175%) in index leaves of coconut trees in sandy soils. Foliar nutrient levels of coconut trees grown in laterite soils were 1.21% N, 0.142% P, 1.27% K, 0.504% Ca and 0.146% Mg. In AEU-3, treatment that received all amendments and nutrients showed highest organic carbon content at the three depths as 6.79 g kg-1soil, 5.39 g kg-1 soil and 3.82 g kg-1,soil, respectively. In AEU-3, 61% increase in yield was observed, while in AEU-9,40% increase was recorded. Application of gypsum resulted in downward displacement of K and Mg indicating that gypsum is required for the amelioration of sub soil acidity in sandy soils. However, the displacement effect was less pronounced in laterite soils and beneficial effect of gypsum was evident with the enhancement of exchangeable Ca. Hence sandy soils require application of inputs as per T3 (T1 without gypsum), with external organic inputs and palm residues whereas in laterite soils application of treatments as per T1 is required with in situ palm residue recycling.
Laboratory rearing of tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae) on cocoa (Theobroma cacao L.)
(2024) T. N. Madhu; E. K. Saneera; R. Thava Prakasa Pandian; Bhavishya; M. Chaithra; M. Sujithra; N. R. Nagaraja; B. J. Nirmal Kumar; S. Elain Apshara
Tea mosquito bug (TMB), Helopeltis theivora is a most serious pest on cocoa worldwide that inflicts huge economic losses under epidemic situations. Laboratory colonies are necessary to perform year-round research to develop suitable management strategies for this pest. This study aimed to establish a population of TMB on suitable cocoa-feeding substrates under laboratory conditions. We used green cocoa pods and tender shoots as a food substrate and compared the biological parameters of H. theivora between them. The adult females preferred to lay more eggs on pods (32.20 ± 1.86 eggs/female) either singly or in a small group, and low fecundity was observed on shoots (20.75 ± 1.16 eggs/female). Meanwhile, egg hatching was highest on pods (92.48 ± 2.91%) than on shoots (74.08 ± 3.73%). This pest consists of five nymphal instars and the total nymphal duration was 13.53 ± 1.26 and 14.73 ± 0.85 days on pods and shoots, respectively. In addition, the per cent survival of H. theivora was highest on pods (78.66 ± 3.46) and lowest on shoots (51.85 ± 2.33). Significant differences were recorded in adult longevity and the mean life span of males and females were 13.17 ± 1.58 and 16.63 ± 1.64 days on pods; 11.10 ± 1.41 and 14.36 ± 1.53 days on shoots, respectively. Further, females lived longer than males in both substrates. Although, TMB will survive both on pods and tender shoots; rearing on pods could be more suitable and reliable to establish a sizable population of H. theivora under laboratory conditions.
Field detection, molecular characterization and biology of the tea tortrix, Homona coffearia Neitner (Lepidoptera: Tortricidae) on Cocoa (Theobroma cacao. L) from India
(2024) Madhu T. N.; Saneera E. K; R. Thava Prakasa Pandian; Bhavishya; Nagaraja N. R; M. Chaithra; S. Elain Apshara; B. J. Nirmal Kumar; Diwakar Y; Suchithra M; Rajesh M. K; Vinayaka Hegde
Cocoa (Theobroma cacao. L) is an important commercial crop widely cultivated in humid tropical regions; however, its production faces various constraints including insect pests. The survey conducted in 2022–2023 found significant damage to cocoa nurseries and fields caused by the larvae of H. coffearia. The caterpillars web the young leaves, feeds within the sheltered nests and affects the crop canopy. The percent incidence was 27.55 ± 1.81% in the nursery and 43.77 ± 3.42% in open fields. A detailed morphological examination and molecular characterization using the mitochondrial cytochrome c oxidase I (COI) gene confirmed the identity of the pest as H. coffearia. The study also documented the key biological parameters of H. coffearia on cocoa under laboratory conditions. The life cycle from egg to adult was completed in about 49 ± 2.32 days. Female moths laid an average of 106 ± 3.48 eggs, which hatched into larvae that underwent five instars before pupation. Both the larval and pupal stages lasted around 27.69 ± 0.72 and 7.72 ± 0.17 days respectively. To our knowledge, this is the first report of the tea tortrix, H. coffearia infesting cocoa in India. As a polyphagous pest, the ability of H. coffearia to adapt and feed on new host plants like cocoa poses a significant threat to cocoa production. The findings of this work highlight the need for further research on the population dynamics, damage potential and management strategies for this emerging pest in cocoa ecosystems.
Effect of temperature on the biological parameters of pink bollworm, Pectinophora gossypiella Saunders (Lepidoptera: Gelechiidae)
(2024) Madhu T. N.; Mohan, K.M; Keerthi, M.C; Prabhulinga, T; Thube, S. H.; Shah, V; Elansary, H.O.; Mousa, I.M.; Mohamed A. El-Sheikh
Pink bollworm (PBW) Pectinophora gossypiella is an important pest cotton worldwide. There are multiple factors which determines the occurrence and distribution of P. gossypiella across different cotton growing regions of the world, and one such key factor is ‘temperature’. The aim was to analyze the life history traits of PBW across varying temperature conditions. We systematically explored the biological and demographic parameters of P. gossypiella at five distinct temperatures; 20, 25, 30, 35 and 40 ± 1 °C maintaining a photoperiod of LD 16:8 h. The results revealed that the total developmental period of PBW shortens with rising temperatures, and the highest larval survival rates were observed between 30 °C and 35 °C, reaching 86.66% and 80.67%, respectively. Moreover, significant impacts were observed as the pupal weight, percent mating success, and fecundity exhibited higher values at 30 °C and 35 °C. Conversely, percent egg hatching, larval survival, and adult emergence were notably lower at 20 °C and 40 °C, respectively. Adult longevity decreased with rising temperatures, with females outliving males across all treatments. Notably, thermal stress had a persistent effect on the F1 generation, significantly affecting immature stages (egg and larvae), while its impact on reproductive potential was minimal. These findings offer valuable insights for predicting the population dynamics of P. gossypiella at the field level and developing climate-resilient management strategies in cotton

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