Browsing by Author "Bhavishya"
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Item 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.KItem BORDEAUX MIXTURE - A UNIVERSAL BLEND FOR Phytophthora MANAGEMENT IN ARECANUT(2020) Thava Prakasa Pandian, R.; Shivaji Hausrao Thube; Chaithra, M.; Nagaraja, N.R.; Bhavishya; Ganesh N. Khadke; Jose, C.T.Item 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. HegdeArecanut 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.Item AN EMERGING PEST IN ARECANUT : PENTATOMID BUG,Halyomorpha picus(2020) Shivaji Hausrao Thube; Saneera, E.K; Pandian, R.T.P.; M. Chaithra; Nagaraja, N.R.; Priya, U.K; BhavishyaItem 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 HegdeCocoa (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.Item 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 HegdeArecanut 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.Item Genotypic variation in flowering, fruit set, and cherelle wilt, and their relationship with leaf nutrient status in cocoa (Theobroma cacao L.) grown in humid tropics of India(2024) Bhavishya; Ravi Bhat; S. Elain Apshara; T. N. Pushpa; D. Srikanta Prasad; H. Nayana; S. H. Thube; R. T. P. Pandian; S. V. RameshCocoa is an important plantation crop grown for its beans, used in the chocolate and confectionary industry. It produces a large number of perfect flowers on the stem (cauliflorous), but the fruit set is low. There is a lack of comprehensive information regarding the genotypic variability in flowering, fruit set, and cherelle wilt, as well as their relationship with leaf nutrient status. Thus, a field study was undertaken at ICAR-Central Plantation Crops Research Institute, Regional Station, Vittal, to elucidate the influence of leaf nutrient status on flowering, fruit set, and cherelle wilt in cocoa. The study revealed significant variations among twenty cocoa genotypes for flower production, fruit set, and cherelle wilt. The highest number of flowers (106) produced on a one-meter marked area on the stem and fruit set (13.7) was recorded in VTLC 05. The lowest number of flowers was observed in genotype VTLCH 2 (16). The maximum fruit set percentage was found in VTLC 182 (13.8%), whereas the minimum fruit set percentage was observed in VTLC 30A (1.3%). Cherelle wilt was maximum in upper Amazon clone VTLC 155 (72.9%), whereas the lowest cherelle wilting percentage was recorded in VTLC 148 (22.9%). Pearson’s correlation coefficients indicated that fruit setting percentage in different genotypes had no significant association with leaf nutrient status, except for calcium which had a significant association (r = 0.596). The result indicated that genotypic variability exists for fruit set and cherelle wilt, and an optimum level of calcium should be maintained in the leaf for better fruit setting in cocoa.Item Good Agricultural Practices in Arecanut Cultivation(2025-01-01) Bhavishya; Ravi Bhat; Sujatha, S.; Rajesh, M.K.; Nagaraja, N.R.; Thava Prakasa Pandian, R.; T. N. MadhuItem Harvesting and processing(2016) Elain Apshara, S.; BhavishyaItem 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 ApsharaTea 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.Item Major storage insect pests of Arecanut Areca catechu L.: A Survey(2017) Shivaji Hausrao Thube; RTP Pandian; Bhavishya; Saneera, E.K; Chandrika Mohan; Nagaraja, N.R.Item Micronutrient management in arecanut-cocoa ecosystem(2021) Bhavishya; H. Nayana; Priya, U.K; Sujatha, S.; Ravi BhatItem Nano-potassium intercalated composted coir pith: A slow-release fertilizer suitable for laterite soils of humid tropics of India(2024) Bhavishya; Kizhaeral Sevathapandian Subramanian; Murali Gopal; Ravi Bhat; Swapna Shanmukan Nair; Malavika Radhakrishnan; Rajesh, M.K.High potassium (K)-demanding plantation crops are grown in laterite soils of the humid tropics of India; these soils generally contain low to medium K content. Nano-fertilizers offer an excellent alternative to conventional fertilizers as they release nutrients slowly for a longer period, enhancing their use efficiency. In this study, nano-zeolite based K fertilizer (NZK) was synthesized and intercalated into raw coir pith (CNZK) and composted coir pith (CCNZK). These were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and UV–visible spectroscopy, and the intercalation of NZK was confirmed. The K content in CNZK and CCNZK was estimated to be 27.2% and 31.6%, respectively. Desorption studies indicated that nano-potassium fertilizer alone, and when intercalated into the composted coir pith, was found to release K slowly for a longer period (>480 h) in the laterite soils. Our study suggests that nano-potassium intercalated composted coir pith can be synthesized for slow release of K in the laterite soils of the humid tropics of India.Item Nano-potassium intercalated composted coir pith: A slow-release fertilizer suitable for laterite soils of humid tropics of India(2024) Bhavishya; Kizhaeral Sevathapandian Subramanian; Murali Gopal; Ravi Bhat; Swapna Shanmukan Nair; Malavika Radhakrishnan; Rajesh, M.K.High potassium (K)-demanding plantation crops are grown in laterite soils of the humid tropics of India; these soils generally contain low to medium K content. Nano-fertilizers offer an excellent alternative to conventional fertilizers as they release nutrients slowly for a longer period, enhancing their use efficiency. In this study, nano-zeolite based K fertilizer (NZK) was synthesized and intercalated into raw coir pith (CNZK) and composted coir pith (CCNZK). These were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and UV–visible spectroscopy, and the intercalation of NZK was confirmed. The K content in CNZK and CCNZK was estimated to be 27.2% and 31.6%, respectively. Desorption studies indicated that nano-potassium fertilizer alone, and when intercalated into the composted coir pith, was found to release K slowly for a longer period (>480 h) in the laterite soils. Our study suggests that nano-potassium intercalated composted coir pith can be synthesized for slow release of K in the laterite soils of the humid tropics of India.Item New ooccurrence of the Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) infestation on cocoa in India.(2023) Madhu, T.N.; Thava Prakasa Pandian, R; Elain Apshara, S.; Bhavishya; Josephrajkumar, A.; Nirmal Kumar, B.J.; P. Santhosh KumarSpodoptera litura (Fabricius) (Lepidoptera: Noctuidae) is a highly polyphagous insect pest, which inflicts serious economic damage on many agricultural and horticultural crops globally. During our recent surveillance surveys, an unusual defoliation was noticed by a caterpillar pest on cocoa saplings at ICAR - Central Plantation Crops Research Institute, Regional Station, Vittal farm, Karnataka, India. Morphological identification and molecular characterization using mitochondrial cytochrome-c-oxidase (COI) gene confirmed the collected insect samples as S. litura. Hitherto, this species was only known to infest Leucaena leucocephala (CABI), a shade tree of cocoa plantations in Indonesia. To the best of our knowledge, this is the first record of infestation by tobacco cut worm on cocoa in India. Consequently, solarization of rooting medium has been suggested for the destruction of the quiescent pupal stage.Item Nutrient management for sustained productivity of Arecanut(2016) Ravi Bhat; Sujatha, S; Bhavishya; Karthika, K.SItem Production systems and canopy architecture(2016) Elain Apshara, S.; Bhavishya; Karthika, K.S.Item Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae) and Its Fungal Symbiont Ambrosiella roeperi Associated with Arecanut Kernel Decay in Karnataka, India(2022) Shivaji Hausrao Thube; Thavaprakaash. N; Bhavishya; Merin Babu; Josephrajkumar, A.; Muddumadiah Chaithra; Vinayaka Hegde; Enrico RuzzierXylosandrus crassiusculus (Coleoptera: Curculionidae: Scolytinae) is reported causing damage to areca palm plantations (Areca catechu L.—Arecaceae) in Karnataka (India). In particular, X. crassiusculus has been observed attacking and successfully reproducing on areca nuts; besides the new host plant record, the data provided here represent the first documented case of spermatophagy for this xyleborine beetle. All infestation symptoms of this polyphagous pest were documented and illustrated. The identity of the scolytid, besides morphologically, was confirmed by its DNA barcoding. Eggs, larvae and pupae were found within the galleries of infested kernels. All galleries of the infested kernels were characterized by the presence of whitish to greyish fungal growth. The fungus was identified as Ambrosiella roeperi, a known symbiont of Xylosandrus crassiusculus. Incidence of this symbiotic insect-fungus complex in the economic part of arecanut, i.e., the kernel, is of serious concern. In a climate change scenario, this beetle with fungal symbionts may pose a serious threat to arecanut production in India and elsewhere.Item Xylosandrus crassiusculus (Motschulsky) on Cocoa Pods (Theobroma cacao L.): Matter of Bugs and Fungi(2022) Shivaji Hausrao Thube; R. Thava Prakasa Pandian; Josephrajkumar, A.; Bhavishya; Nirmal Kumar, B.J.; Dnyaneshwar M. Firake; Vivek Shah; T. N. Madhu; Enrico Ruzzier