Browsing by Author "Josephrajkumar, A."

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    A new pod bioassay method to determine the toxicity of insecticides against Tea mosquito bug, Helopeltis theivora
    (2024) T. N. Madhu; Saneera, E.K; R. Thava Prakasha Pandian; Sujithra, M; Bhavishya; Nagaraja, N.R.; Elain Apshara, S.; Josephrajkumar, A.; Rajesh, M.K
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    Bio- cleansing of coconut palms infested by Rugose spiralling whitefly
    (2018-01) Josephrajkumar, A.; Chandrika Mohan; Poorani, J; Merin Babu; Krishnakumar, V.
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    Biocontrol potential of Heterorhabditis indica against the maggot of Bactrocera cucurbitae (Diptera: Tephritidae)
    (2017) Mary Nirmala Borgia; Josephrajkumar, A.; Mary Teresa P. Miranda
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    Bioefficacy of peat formulation of bacterial antagonists on growth promotion and disease suppression in cardamom (Elettaria cardamomum Maton)
    (2012) Sivakumar, G.; Josephrajkumar, A.; Rangeshwaran, R.
    Among the 90 rhizobacterial isolates screened against capsule rot pathogen of cardamom Phytophthora meadii Mc Rae two bacterial strains viz., Pseudomonas fluorescens Pf 51 and Bacillus subtilis Bs were found highly inhibitory. Strain Pf 51 exhibited highest inhibition (40.2%) against P. meadii. Similarly B.subtilis strain Bs also exhibited highest inhibition (39.7%) against P. meadii. P. fluorescens strain Pf51 was found compatible with strain B. subtilis Bs. Application of antagonists both Pf 51 and Bs in combination with rhizome bacterization and soil application resulted in 60% reduction of capsule infection over control as compared to single methods such as rhizome bacterization (53%) and soil application (46%). Application of copper oxy chloride resulted in 73% reduction of capsule infection. Maximum height (169.7cm) and number of tillers (36.3) were recorded due to the application of mixture of both the strains through rhizome bacterization and soil application.
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    Climate change and crop yields in the Indian Cardamom Hills, 1978–2007 CE
    (2011-06) Murugan, M.; Shetty, P.K.; Ravi, R.; Anandhi, A.; Josephrajkumar, A.
    In this study we analyzed climate and crop yields data from Indian cardamom hills for the period 1978–2007 to investigate whether there were significant changes in weather elements, and if such changes have had significant impact on the production of spices and plantation crops. Spatial and temporal variations in air temperatures (maximum and minimum), rainfall and relative humidity are evident across stations. The mean air temperature increased significantly during the last 30 years; the greatest increase and the largest significant upward trend was observed in the daily temperature. The highest increase in minimum temperature was registered for June (0.37◦C/18 years) at the Myladumpara station. December and January showed greater warming across the stations. Rainfall during the main monsoon months (June–September) showed a downward trend. Relative humidity showed increasing and decreasing trends, respectively, at the cardamom and tea growing tracts. The warming trend coupled with frequent wet and dry spells during the summer is likely to have a favorable effect on insect pests and disease causing organisms thereby pesticide consumption can go up both during excess rainfall and drought years. The incidence of many minor pest insects and disease pathogens has increased in the recent years of our study along with warming. Significant and slight increases in the yield of small cardamom (Elettaria cardamomum M.) and coffee (Coffea arabica), respectively, were noticed in the recent years.; however the improvement of yield in tea (Thea sinensis) and black pepper (Piper nigrum L.) has not been seen in our analysis.
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    Coconut Eriophyid Mite,Aceria guerreronis Keifer
    (2003) Rajan, P.; Chandrika Mohan; Josephrajkumar, A.
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    Coconut leaf Beetle(Brontispa longissima)-An inavasive pest of concern
    (2009-10) Rajan, P.; Nair, C.P.R.; Josephrajkumar, A.; Chandrika Mohan
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    Competitive regulation of dominant exotic whiteflies on coconut palms as influenced by biotic and abiotic factors
    (2023) Logeshkumar, P; Nalini, R; Josephrajkumar, A.; Chandramani, P; Mini, M.L; Durai Singh, R; Murugan, M; Suresh, K
    In the recent past, exotic whiteflies viz., Aleurodicus rugioperculatus, Paraleyrodes bondari, Paraleyrodes minei and Aleurotrachelus atratus are infesting coconut plantations in India. Based on the damage potential, the predominant species are the rugose spiralling whitefly, A. rugioperculatus and the Bondars nesting whitefly, P. bondari. A study was undertaken to determine the seasonal incidence and population dynamics of these in the new invasion region at Karungalakudi block of Madurai district from 33rd standard meteorological week (SMW) of 2021 to 32nd SMW of 2022. The results indicated that A. rugioperculatus incidence rose considerably from the first week of April (10.9 adults/ leaflet) to third week of May (8.3 adults/ leaflet; while P. bondari reached maximum during the third week of March (71.99 adults/ leaflet) and extended up to first week of June (67.57 adults/ leaflet) coinciding with summer months with high temperature and limited precipitation. Subsequently, their incidence declined with the onset of north east monsoon coupled with parasitism by Encarsia guadeloupae and predation by chrysopids from thirdweek of August to fourth-week of December in 2021. The extent of parasitism by E. guadeloupae on A. rugioperculatus nymphs was positively correlated and ranged from 40% (third week of August, 33rd SMW, 2021) to 84% (second week of June 2022, 24th SMW). Chrysopids revealed a highly significant positive correlation with the incidence.
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    Disrupting Insect Luminal Enzymes for Pest management
    (2014) Josephrajkumar, A.; Chandrika Mohan
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    Distinguishing palm aphid and arecanut whitefly, two emerging pests in palms
    (2013-06) Josephrajkumar, A.; Rajan, P.; Chandrika Mohan; Namboothiri, C.G.N.
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    Diversity and management of scale insects infesting coconut
    (2011-01) Josephrajkumar, A.; Rajan, P.; Chandrika Mohan; Namboothiri, C.G.N.
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    Ecological Bio-engineering in Coconut Ecosystem to deter pests
    (2018-10) Josephrajkumar, A.; Chandrika Mohan; Thomas, R.J.; Krishnakumar, V.
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    Efficacy of botanical formulations against coconut rhinoceros beetle, Oryctes rhinoceros.
    (2023) Alagar, M.; Srinivasan, T.; Rajamanickam, K.; Josephrajkumar, A.; Yasmin, A.; Chinnadurai. S; Sivakumar, V.; Praneetha, S.; Maheswarappa, H.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 bacterial antagonists for the management of rhizome rot of cardamom (Elettaria cardamomum Maton)
    (2012) Sivakumar, G.; Josephrajkumar, A.; Dhanya, M.K.
    Among the 90 rhizobacterial isolates screened against rhizome rot pathogens (Pythium vexans, Fusarium oxysporum and Rhizoctonia solani) of cardamom (Elettaria cardamomum) two bacterial strains viz., Pseudomonas fluorescens Pf 51 and Bacillus subtilis B45 were highly inhibitory. P. fluorescens Pf 51 exhibited highest inhibition (42.5%, 44.2% and 41.4% respectively) against P. vexans, F. oxysporum and R. solani. B. subtilis B45 also exhibited highest inhibition (43.2%, 41.2% and 42.4% respectively) against these three pathogens. P. fluorescens Pf51 was compatible with B. subtilis Bs 45. Peat formulation supported the survival of both the strains up to 270 days with a viable population of 4.3 × 107 cfu g-1 and 6.2 × 107 cfu g-1 respectively. Application of antagonists in combination with rhizome bacterization and soil application resulted in 54.0% reduction in rhizome rot over control as compared to single method such as rhizome bacterization (43.0%) or soil application (39.0%). Application of copper oxychloride and carbendazim resulted in 68.0% reduction of rhizome rot. Maximum height (167.21 cm) and number of tillers (30.14) were recorded due to the application of mixture of both the strains through rhizome bacterization and soil application.
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    First record of Asian grey weevil (Myllocerus undatus) on coconut from Kerala, India
    (2010) Josephrajkumar, A.; Rajan, P.; Chandrika Mohan; Thomas, R.J.
    The occurrence of Asian grey weevil Myllocerus undatus (Curculionidae: Coleoptera) damaging coconut (Cocos nucifera L.) seedlings is reported for the first time from Kerala, India. A mild to moderate level of infestation damaging 5–10% leaf lamina of un-split leaves with a typical notching-like symptom along the leaf margins is noticed on the majority of the coconut seedlings belonging to different coconut varieties, viz., ‘Chowghat Orange Dwarf’, ‘Chowghat Green Dwarf’, ‘Malayan Green Dwarf’, ‘West Coast Tall’ and Dwarf x Tall hybrids. M. undatus has not been reported as a destructive pest on any of the crops from India and is considered to be a pest of quarantine significance. Adult weevils have a characteristic tri-spined hind femur and elytra strongly angled broader than the prothorax.
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