Informatics Publishing Limited

R. K. Gnanamurthy ¹, V. Krishnakumar ², D. Sathiya ³

Affiliations
1 Audisankara Institute of Engineering and Technology, Gudur, IN
2 Vivekanandha Engineering College for Women, Sankari, IN
3 Department of CSE, Vivekanandha Engineering College for Women, Sankari, IN

Abstract

Broadcasting is the process in which a source node sends a message to all other nodes in MANET. Network wide broadcasting in Mobile Ad Hoc Networks provides important control and route establishment functionality for a number of unicast and multicast protocols. This paper presents an overview of Flooding; Probability based broadcast forwarding, Location based and Neighbor Knowledge method broadcasting techniques in mobile ad hoc networks. The simulations are designed to pinpoint, in each category, specific failures to network conditions that are relevant to MANETs. For instance, protocols such as dynamic source routing (DSR), ad hoc on demand distance vector (AODV), use broadcasting to establish routes. Broadcasting MANET poses more challenges than in wired networks due to node mobility and scarce system resources. Because of the mobility there is no single optimal scheme for all scenarios.

Keywords

AODV-Adhoc on Demand Distance Vector Protocol, DSR-Dynamic Source Routing Protocol, MANET–Mobile Adhoc Network.

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Chandrika Mohan ¹, A. Josephrajkumar ¹, Merin Babu ¹, Arya Krishna ¹, P. S. Prathibha ², V. Krishnakumar ¹, Vinayaka Hegde ²

Affiliations
1 ICAR-Central Plantation Crops Research Institute, Regional Station, Kayamkulam 690 533, IN
2 ICAR-Central Plantation Crops Research Institute, Kasaragod 671 124, IN

Abstract

Field occurrence of the exotic neotropical nesting whitefly, Paraleyrodes minei Iaccarino in association with Bondar’s nesting whitefly, Paraleyrodes bondari Peracchi on coconut leaflets is reported from Kerala, India. These coconut palms were previously infested by the rugose spiralling whitefly, Aleurodicus rugioperculatus Martin, which was reported from Kerala and Tamil Nadu during 2016. P. minei closely resembles P. bondari, but is devoid of the oblique grey bands on the wings and it constructs loosely woven, woolly wax nests. Female P. minei are white, but males are smoky grey. Cockhead-like male aedeagus with two thin appendixes projected downwards is the unique feature for species-level identification of P. minei. Detection of three non-native whiteflies of neotropical origin infesting coconut palms in India within a span of two years suggests their simultaneous introduction. Invasive potential of P. minei due to its polyphagous nature and short lifecycle calls upon strict policy frameworks in exchange of planting materials. Domestic quarantine should be strictly enforced in the country to avoid spread of this pest to other coconut-growing regions.

Keywords

Biosecurity, Coconut Palms, Neotropical Nesting Whitefly, Quarantine, Rugose Spiralling Whitefly.

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K. M. Nair ¹, K. S. Anil Kumar ¹, M. Lalitha ¹, Shivanand ¹, S. C. Ramesh Kumar ¹, S. Srinivas ¹, Arti Koyal ¹, S. Parvathy ¹, K. Sujatha ¹, C. Thamban ², Jeena Mathew ², K. P. Chandran ², Abdul Haris ², V. Krishnakumar ², V. Srinivasan ³, Jessy ⁴, James Jacob ⁴, J. S. Nagaraj ⁵, Maria Violet D’Souza ⁵, Y. Raghuramulu ⁵, R. Hegde ¹, S. K. Singh ¹

Affiliations
1 Regional Centre, ICAR-National Bureau of Soil Survey and Land Use Planning, Hebbal, Bengaluru 560 024, IN
2 ICAR-Central Plantation Crops Research Institute, Kasaragod 671 124, IN
3 ICAR-Indian Institute of Spices Research, Kozhikode 673 012, IN
4 Rubber Research Institute of India, Kottayam 686 009, IN
5 Coffee Research Institute, Chikmagalur 577 117, IN

Abstract

Natural forests and managed plantations constitute the largest land-use systems in the humid tropics of southwestern parts of Peninsular India comprising the Western Ghats and coastal plain. Soils therein are naturally acidic and the acidity is enhanced in managed land-use systems through inputs of chemical fertilizers. Plant nutrient deficiencies and mineral toxicities constrain crop production in acid soils. Surface soil and subsoil acidity in forest, coffee, rubber and coconut land-use systems was evaluated. The spatial pattern of surface soil and subsoil acidity pointed to low intensity of acidification in Malnad region of Karnataka, moderate acidity in northern Kerala and strong acidity in southern Kerala. Among the land-use systems studied, soils under natural forests and coffee plantations were only slightly acidic in surface soil and subsoil, whereas rubber- and coconut-growing soils were strongly acidic. Both natural and managed land-use systems, however, had strongly acid reaction in surface soil and subsoil in southern Kerala. Biomass production and crop yield are constrained in strongly acid soil by toxic levels of aluminium (Al) on soil exchange complex (>0.5 cmol (+) kg^–1 soil) and depletion of basic cations of calcium, magnesium and potassium (base saturation less than 50% or Al saturation more than 50%). Surface soil acidity can be ameliorated by incorporating liming materials into surface soils. In case of subsoil acidity gypsum too should be incorporated. Under humid climate partial solubility of gypsum permits movement of calcium into the subsoil layers, wherein calcium replaces the aluminium on exchange complex and sulphate radical precipitates the aluminium by formation of aluminium sulphate.

Keywords

Base Saturation, Humid Tropics, Land-Use Systems, Surface Soil and Subsoil Acidity.

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A. Josephrajkumar ¹, Chandrika Mohan ¹, Merin Babu ¹, P. S. Prathibha ², Vinayaka Hegde ², V. Krishnakumar ¹

Affiliations
1 ICAR-Central Plantation Crops Research Institute, Regional Station, Kayamkulam 690 533, IN
2 ICAR-Central Plantation Crops Research Institute, Kasaragod 671 124, IN

Abstract

As many as four exotic whiteflies of Neotropical origin have been reported from different coconut-growing regions in India in rapid succession in the last four years. The spiralling whitefly, Aleurodicus dispersus Russell was the earliest reported invasive species on coconut from Kerala in 1996. The rugose spiralling whitefly, Aleurodicus rugioperculatus Martin was first reported in 2016 followed by three species (Paraleyrodes bondari, Paraleyrodes minei and Aleurotrachelus atratus) in 2019. At present, all are found to coexist on coconut in South India. In such combined incidences, one species occupies the breeding and feeding niche of another under optimum weather parameters and attempts to displace one or more of its competitors. The Bondar’s nesting whitefly, P. bondari is associated with rugose spiralling whitefly in most districts of Kerala and Tamil Nadu, whereas the nesting whitefly P. minei is interlinked with A. rugioperculatus in Kasaragod, Kerala, and also found to co-occur with the palm whitefly, A. atratus in Mandya, Karnataka. In Kayamkulam, Kerala, P. bondari, P. minei and A. rugioperculatus co-lived for a brief period during 2018. Due to the incursion and subsequent coexistence of these exotic whiteflies which share more or less the same niche with similar habits on coconut, it is imperative to identify them correctly for carrying out further studies on their bioecology, population dynamics and management. Hence an illustrated diagnostic account of these exotic whiteflies is given here to facilitate their visual identification by economic entomologists and field workers. The COI sequences of these exotic whiteflies are also given to enable rapid confirmation of the field diagnosis.

Keywords

Bioinvasion, Coconut, Coexistence, Exotic Whiteflies, Field Diagnosis.

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