Browsing by Author "Vinayaka Hegde"

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    Arecanut diseases and their Management
    (2016) Chowdappa, P.; Vinayaka Hegde; Chaithra, M; Thava Prakasa Pandian, R
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    Coconut community in India -a profile
    (CPCRI, 2001-09) Arulraj, S.; Rajagopal, V.; Sairam, C.V.; Thamban, C.; Anithakumari, P.; Dhanapal, R.; Bosco, S.J.D.; Subaharan, K.; Naresh Kumar, S.; George V. Thomas; Vinayaka Hegde; Kumaran, P.M.; Parthasarathy, V.A.
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    Coconut: Maladies and Remedies
    (2018) Rohini Iyer; Gunasekharan, M.; Vinayaka Hegde
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    Control Efficiency and Yield Response of Chemical and Biological Treatments against Fruit Rot of Arecanut: A Network Meta-Analysis
    (2022) Balanagouda Patil; Shankarappa Sridhara; Hanumappa Narayanaswamy; Vinayaka Hegde; Ajay Kumar Mishra
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    Data of 16S rRNA gene amplicon-based metagenomic signatures of arecanut rhizosphere soils in Yellow Leaf Disease (YLD) endemic region of India
    (2021) Paulraj, S.; Ravi Bhat; Rajesh, M.K.; Ramesh, S.V.; Priya, U.K; Thava Prakasa Pandian, R.; Vinayaka Hegde; Chowdappa, P.
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    Development and evaluation of fungicide-amended urea briquettes (FAUB’s) to combat fruit rot disease of arecanut: A farmers-friendly approach
    (2023) Balanagouda Patil; Hanumappa Narayanaswamy; Vinayaka Hegde; Shankarappa Sridhara; Thava Prakasa Pandiyan, R; Shivaji Hausrao Thube
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    Development of rapid, efficient and cost effective screening technique for testing arecanut against Phytophthora meadii incitant of fruit rot disease
    (2024) Prathibha, P.S.; Nagaraja, N.R.; Rajesh, M.K.; Daliyamol; K. P. Thejasri; Rajkumar; Vinayaka Hegde; Uchoi Anok
    To accelerate identification of disease resistant arecanut germplasm or hybrids against Phytoph- thora , it is very much imperative to develop bioassays which could differentiate resistant and susceptible cultivars efficiently. Here, a cost effective and rapid technique, called the “Detached Leaf Assay ”, was developed to identify resistant germplasm at the seedling stage itself. Zoospore production in highly virulent Phytophthora meadii (P19) was standardized by incubating under a 12 hours light and dark regime. Zoospore suspension was adjusted to 105 spores ml-1 in Petri plates. Subsequently, surface sterilized arecanut leaves were floated in zoospore suspension and incubated at temperature of 24 ± 1 °C. Disease symptoms, including water-soaked lesions, were recorded three days after inoculation. Infection lesion increased from 1 to 7.3 cm2 . The pathogen was re-isolated and confirmed with the original culture. The assay was successfully validated to screen arecanut accessions, wild types and hybrids against P. meadii . This technique is the first to be developed, and it is simple, cost-effective, and faster. It also provides consistent infection and could be effectively utilized to screen arecanut germplasm or hybrids against P. meadii in the seedling stage itself.
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    Diagnosis of invasive whitefly species co-occurring on coconut
    (2020-10) Joseph Rajkumar, A.; Chandrika Mohan; Merin Babu; Prathibha, P.S.; Vinayaka Hegde
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    Differentiation of Phytophthora species associated with plantation crops using PCR and high-resolution melting curve analysis
    (2018) Prathibha, V.H.; Vinayaka Hegde; Sharadraj, K.M; Rajesh, M.K; Rachana, K.E.; Chowdappa, P
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    Discovery of Aleuroclava canangae (Corbett) (Hemiptera: Aleyrodidae) on Coleus in India and the establishment and review of the Aleuroclava canangae species group
    (2024) Arulappan Josephrajkumar; Gregory Evans; Merin Babu; Kakkanattu Meerasahib Anes; Jilu V. Sajan; Vinayaka Hegde
    Aleuroclava canangae (Corbett, 1935) was discovered on an ornamental Coleus species in Kerala, India, and represents the first occurrence of this species in India and on this plant host. The species is redescribed and illustrations of the puparium and adult males and females are provided along with morphometric data. A molecular analysis of the species using the COI gene was conducted to characterise it, determine its genetic lineage and compare it to seven other species of Aleuroclava Singh, 1931 and those of other whitefly genera. Results of the DNA analysis indicate that A. canangae forms a clade with Aleuroclava indica (Singh, 1932) which also has two pairs of very elongate, tuberculate setae which appear two-jointed because they have a wider basal part separated from a long slender apical part by a fine suture. The Aleuroclava canangae species group is established and an illustrated key is provided for the 12 species in the group, all of which were once placed in the genus Martiniella Jesudasan and David, 1990, now a synonym of Aleuroclava. The molecular analysis indicates that A. psidii (Singh, 1931), A. guyavae (Takahashi, 1932), A. montanus (Takahashi, 1939) and A. gordoniae (Takahashi, 1932) form a clade within the genus Aleuroclava and share similar morphological characters. Based on the results of the molecular and morphological analyses, Aleurothrixus trachoides (Back, 1912) is transferred back to Aleurotrachelus trachoides (Back, 1912) based on its morphology and the results of the DNA analysis.
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    Diseases
    (2017) Vinayaka Hegde; Prathibha, V.H.; Chowdappa, P.
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    Enhancing farmer's income by growing disease-free coconut
    (2017) Vinayaka Hegde; Prathibha, V.H.; Chowdappa, P.
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    Euwallacea perbrevis (Schedl, 1951) and associated novel fungal symbiont, Fusarium sp.: A potential cause of wilting in cocoa, Theobroma cacao in India
    (2024) Shivaji Hausrao Thube; R Thava Prakasa Pandian; Rajkumar; Merin Babu; Josephrajkumar, A.; Santhoshkumar P; B.J. Nirmal Kumara; Vinayaka Hegde; Balanagouda Patil; H. Rajashekara; T. Prabhulinga; Babasaheb B. F; Shailesh Gawande; Dipak Nagrale; M. Devindrappa; Rajesh, M.K.
    Cocoa is a commercially important beverage crop that faces new challenges in the context of climate change, which can alter pest and disease dynamics in cocoa plantations. In the Dakshina Kannada district of Karnataka, India, an abrupt increase in cocoa wilt was observed during the 2017–18 and 2018–19 seasons. Systematic examination of affected trees revealed consistent attacks of Euwallacea perbrevis (Schedl, 1951; Coleoptera: Curculionidae: Scolytinae). In-depth studies of the wilted trees revealed the association of the plant pathogenic fungus Fusarium sp. with Euwallacea perbrevis. The identity of the obtained pure culture from the insect and infected tree was confirmed as Fusarium sp. using amplification of ribosomal DNA, RNA polymerase II largest subunit (RPB1) and translation elongation factor 1 (Tef1) genes. Notably, this study reports a remarkable case of mutualistic association between ambrosia beetles and Fusarium sp., belonging to the Fusarium solani species complex (FSSC), rather than the Ambrosia Fusarium clade (AFC). This finding highlights the intriguing diversity of mutualistic relationships in nature and sheds new light on the complex interactions between organisms. The present study also investigated the impact of rainfall on the colonization and spread of the Euwallacea-Fusarium complex. The findings revealed that rainfall was identified as a predisposing factor for the incidence and spread of attacks. Additionally, the study conducted a comprehensive analysis of the modeling of Euwallacea-Fusarium complex spread over a specific period of time.
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    Evaluation of a native isolate of Metarhizium anisopliae (Metschn.) Sorokin TMBMA1 against tea mosquito bug, Helopeltis theivora infesting cocoa (Theobroma cacao L.)
    (2022) Shivaji Hausrao Thube; Thavaprakaash. N; Merin Babu; Josephrajkumar, A.; Priyank Hanuman Mhatre; P. Santhosh Kumar; B.J. Nirmal Kumar; Vinayaka Hegde; Satish Namdeo Chavan
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    Evaluation of Combinatorial Capacity of Coconut and Cocoa Plant Growth Promoting Rhizobacteria (PGPR) with Biocontrol Agent Trichoderma harzianum
    (2018) Khadeejath Rajeela, T.H.; Alka Gupta; Murali Gopal; Vinayaka Hegde; George V. Thomas
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    Evaluation of locally available substrates for mass production of Trichoderma
    (2015-08) Prathibha, V.H.; Sharadraj, K.M.; Nidhina, K.; Vinayaka Hegde
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    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.
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    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.
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    FIRST RECORD OF THE INVASIVE NEOTROPICAL AMBROSIA BEETLE EUPLATYPUS PARALLELUS (FABRICIUS, 1801) COLEOPTERA: CURCULIONIDAE: PLATYPODINAE) INFESTING ARECANUT IN KARNATAKA, INDIA
    (2018) Shivaji Hausrao Thube; Chandrika Mohan; RTP Pandian; Saneera, E.K; Sannagoudra, H.M; Vinayaka Hegde; Chowdappa, P