Influence of meteorological parameters on leafhopper vector population and sesame phyllody disease incidence in Assam, India

2019 ◽  
Vol 9 (1) ◽  
pp. 173
Author(s):  
Manoj Kumar Kalita ◽  
Ashok Kamal Gogoi ◽  
Shankar Hemanta Gogoi ◽  
Jutimala Phookan ◽  
Palash Deb Nath ◽  
...  
Keyword(s):  
Meteorological Parameters ◽  
Disease Incidence ◽  
Leafhopper Vector ◽  
Vector Population

scholarly journals Epidemiological Factors Influencing the Development of Pigeonpea Sterility Mosaic Virus Disease in Pigeonpea

2020 ◽  
Author(s):  
M. S. Pallavi ◽  
H. K. Ramappa ◽  
R. Harischandra Naik
Keyword(s):  
Early Stage ◽  
Disease Incidence ◽  
Research Work ◽  
Severe Form ◽  
Crop Growth ◽  
Mite Population ◽  
Time Interval ◽  
Vector Population ◽  
Artificial Environment ◽  
The Impact

Background: In a region of Karnataka, India with a varied type climate PPSMV infection on pigeonpea occurs in a severe form and considered as green plague and one of the most devastating diseases as it appear in severe form resulting in reduction of 100% yield loss transmitted by vector eriophyid mite Aceriacajani Channabasavanna. However, not much systematic and strategic research work being carried out on epidemiology. In spite of various control measures, Sterility Mosaic Disease has continued to be major constraint in pigeonpea production. A lot of variation exists among the genetic background of different varieties in different regions. These variations render it difficult to evolve a common management strategy to control SMD epidemics. Therefore, it is necessary to know the severity of disease and factors associated with disease development which helps in devising suitable management practices. Methods: To study the influence of sowing dates on SMD and vector population under field conditions. A total of twelve sets of sowings were made at different time interval starting from first week of January 2012 to December, 2012. The SMD disease incidence and mite population were recorded in each treatment at fifteen days interval. Under artificial environment, pigeonpea seedlings of variety ICP8863 were raised. Inoculation of virus was done at different stage of plant growth viz., 15, 30, 45, 60, 75, 90 days after sowing. The observation on terminal disease incidence was recorded at 90 DAS to study the impact of host age on SMD. The eight pigeonpea varieties were sown near the SMD infected plot so as to facilitate the movement of vector population under natural conditions to study the reaction of pigeonpea varieties to SMD. Naturally grown weeds present in and around the sterility mosaic screening nursery were collected at weekly interval to see the presence of mites. In a glass house experiment, twenty-three cultivated species of economic importance and three Nicotiana species were sown three replications to see the alternate host for the virus. Results: The fluctuation in disease incidence and mite population was recorded throughout the year and early stage of crop growth recorded less disease incidence with lower mite population and gradual increase was recorded at later stage of crop growth period. The maximum disease incidence and mite population was recorded in crop sown during month of June and July where mean temperature was 24 to 26oC, RH 67 to 71% and rainfall of 2.13mm. The disease incidence recorded at different months of sowing had a significant positive correlation with mite population. Pigeonpea plants inoculated up to age of 30 days showed complete sterility with 100% disease incidence. The Resistant genotypes recorded less per cent disease incidence and symptom development at 60DAS. Whereas susceptible variety recorded maximum diseases incidence at early stage of crop growth and showed complete sterility. PPSMV and its vector survived on the ratooned pigeonpea plants and its wild relatives Atylosiascaraboeides during off season.

scholarly journals Hemipteran Hopper Species Associated with Acid Lime Plants (Citrus aurantifolia L .) in the Sultanate of Oman: Candidate Vectors of Witches’-Broom Disease of Lime

2007 ◽  
Vol 12 ◽  
pp. 53 ◽  
Author(s):  
Syed Ali Razvi ◽  
Rashid Al-Shidi ◽  
Najma Mahmood Al-Zadjali ◽  
Yousuf Mohammad Al-Raeesy
Keyword(s):  
Relative Humidity ◽  
Disease Incidence ◽  
Sultanate Of Oman ◽  
Citrus Aurantifolia ◽  
Vector Population ◽  
Broom Disease ◽  
Acid Lime ◽  
Two Phases ◽  
One Year ◽  
Hishimonus Phycitis

Regular monitoring of hemipteran hopper species (including psyllids) associated with small-fruited acid lime trees (Citrus aurantifolia L.) was conducted for four years using motorized insect suction to determine the possible vectors of witches’- broom disease of lime (WBDL). The study was done in two phases: monitoring was done in Habra village, Wilayat Wadi AlMaawal (Batinah region) for one year from June 2000 to May 2001; then monitoring was done in Maharah village, Wilayat AlMusannah (Batinah region), for a period of three years from May 2001 to April 2004. Twelve species of cicadellid leafhoppers and one delpahacid planthopper species were collected, while no psyllids were found. Hishimonus phycitis (Distant) (Cicadellidae) was the most abundant hopper (78.4 % of collected individuals). Next in abundance were Toya sp. (Delphacidae), Circulifera haematiceps? and a deltocephalin leafhopper, respectively constituting 10.4, 3.8 and 2.4 % of the total catches of the four years. Nine other species made up 5% of the total collection: Exitianus nanus (Distant), Cicadulina sp. (either chinai (Ghauri) or storeyi (China)), Emposca distinguenda (Paoli), Amrasca biguttula (Ishihara), Deltocephalus (Recilia) pruthii (Metcalf), Neolimnus aegyptiacus (Mutsumura) and three undetermined species (one Deltocephalinae, one Typhlocybinae and one undeterminable to subfamily). Catches of H. phycitis were highest from November to March and lowest from May to September. There was a significant linear relationship between number of H. phycitis and maximum and mininmum temperature. Relative humidity was not significantly correlated to number of H. phycitis. In Maharah, young lime trees were free from WBDL but the disease incidence increased with age. H. phycitis is the best candidate vector of WBDL. The potential of Toya sp., Circulifera haematiceps? and an undetermined deltocephalin as candidate vectors is discussed. Finally, it is suggested that regular sprayings of acid lime trees with effective systemic insecticides during November to March each year can greatly reduce the vector population and can prevent or delay the spread of the disease to a great extent.

scholarly journals Evaluation of whitefly population and weather effect of cassava mosaic incidence on commonly grown cassava in Benue State, Nigeria

2020 ◽  
Vol 24 (10) ◽  
pp. 1839-1846
Author(s):  
I Time ◽  
E Okoroafor ◽  
J.O. Nwogwugwu ◽  
A.A. Batcho
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Disease Incidence ◽  
Natural Infection ◽  
Block Design ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Whitefly Population ◽  
North East ◽  
Vector Population

Vector population and weather are critical in virus disease incidence and could be strategic for its management in agriculture. To investigate the influence of whitefly population and weather on Cassava Mosaic Disease (CMD) in cassava, TMS 419 and TME 30572, commonly grown in the state were planted. The varieties were laid out in Randomized Complete Block Design in four replicates and left to natural infection by CMD viruses. At two weeks after planting and fortnightly, whitefly population counts were taken, CMD incidence was estimated and severity scored on 5- point scale. Daily temperature, humidity, wind speed and wind direction were obtained as secondary data. Data were analysed using ANOVA at p=0.05. Whitefly population (18/plant) was significant (P≤0.05) in the first 30 days at 26.9-27.1oC, 42% humidity, 10 Km/hr wind speed and when the wind direction was in the East or North-East. The vector population then declined until the end of experiment. Cassava mosaic incidence changed with whitefly population, humidity and wind speed. Disease incidence in cassava plots was low (3.6%). TME30572 maintained lower disease incidence (3.0%) and severity (2.0) during the study. R2 indicated that 27, 42 and 57% of whitefly population could be explained by temperature, humidity and wind speed, respectively while 4% of the disease incidence could be explained by the whitefly population. The number of CMD infected plants peaked (4%) when population of whitefly was 18/plant, above which the disease reduced at 0.0017 rate per unit change in the vector population. Mosaic disease incidence in cassava plots was influenced by vector population as conditioned by the weather. Keywords: Bemisia tabaci, Cassava, Cassava Mosaic Disease, Nigeria, Weather, Whitefly vector

Community Perception Regarding Mosquito-Borne Diseases in Some Selected Areas of Ganjam District of Odisha State, India

2021 ◽  
pp. 0272684X2110049
Author(s):  
Sisir K Nayak ◽  
Surya N Swain ◽  
T Sarita Achari ◽  
Tapan K Barik
Keyword(s):  
Disease Incidence ◽  
Basic Knowledge ◽  
Health Concern ◽  
Mosquito Vector ◽  
College Level ◽  
Community Perception ◽  
Vector Borne Diseases ◽  
Vector Population ◽  
Vector Borne ◽  
Ganjam District

Mosquito-borne diseases are a major public health concern. Because of absence of effective therapy and vaccination to treat and prevent such vector-borne diseases, these initial cases have triggered strong concerns within medical communities, turning a bad dream into reality. To date, reducing the mosquito vector population remains the main strategy to control the transmission of mosquito borne diseases. In this connection, community-based perception recognized as an essential tool for long-term vector control management. In this study, a community perception survey was carried out in six selected study areas of Ganjam district of Odisha. A total of 3257 inhabitants from randomly chosen 600 no. of houses from 06 selected study areas were interviewed using a pre-tested structured questionnaire about various mosquito vector-borne diseases. As an outcome, we found that only 36% of people have basic knowledge and idea about vector-borne diseases, out of which only 14% know Anopheles as a causative agent whereas Aedes and Culex were very least concern. Regarding the source of knowledge, electronic media was the principal source of information, while the involvements of health personnel were least mentioned. Results of the current study indicates the necessity to plan health education program to bring important perceptions regarding vector-borne diseases at school and college level because the infrequent source of knowledge is the main cause of an increase in the disease incidence.

scholarly journals Effect of meteorological parameters on Karnal bunt incidence in wheat under different agroclimatic zones of Punjab

2022 ◽  
Vol 24 (1) ◽  
Author(s):  
SARABJOT KAUR SANDHU ◽  
ANURAG ATTRI ◽  
RITU BALA
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Significant Positive Correlation ◽  
Meteorological Parameters ◽  
Disease Incidence ◽  
Karnal Bunt ◽  
Maximum Temperature ◽  
Wheat Crop ◽  
Sunshine Hours ◽  
Rainy Days

To quantify the effect of meteorological parameters on incidence of Karnal bunt in wheat crop, an investigation was done using 9 to 12 season’s data of Bathinda and Ludhiana stations of Punjab. Maximum temperature during March in range of 25-31oC, minimum temperature of February (8.5-11.0oC), morning and evening relative humidity of March in range of 85-95 and 40-60 per cent respectively, rainfall more than 25 mm with sunshine hours 5.5-9.0 hrs/day during mid February to mid March favour Karnal bunt in wheat crop. Maximum temperature of March showed significant negative correlation with incidence of Karnal bunt whereas minimum temperature of February showed significant positive correlation with disease incidence at both locations. Morning and evening relative humidity showed significant positive correlation with disease incidence. Rain amount and rainy days during mid February to mid March significantly influenced disease incidence. Sunshine hours had negative correlation with disease incidence. Backward multiple linear regression (BMLR) analysis indicated maximum temperature, rainfall and sunshine hours play significant role in Karnal bunt incidence at Ludhiana. However, at Bathinda, maximum temperature, evening time relative humidity, rain amount and rainy days played significant role.

scholarly journals Phenology of Xylella fastidiosa and Its Vector Around California Almond Nurseries: An Assessment of Plant Vulnerability to Almond Leaf Scorch Disease

Plant Disease ◽  
2012 ◽  
Vol 96 (10) ◽  
pp. 1488-1494 ◽  
Author(s):  
R. Krugner ◽  
C. A. Ledbetter ◽  
J. Chen ◽  
A. Shrestha
Keyword(s):  
Xylella Fastidiosa ◽  
Disease Incidence ◽  
Temporal Distribution ◽  
Enzyme Linked Immunosorbent Assay ◽  
Insect Vector ◽  
In Planta ◽  
Leaf Scorch ◽  
Vector Population ◽  
Infection Pathways ◽  
Almond Leaf Scorch

Management of almond leaf scorch disease requires knowledge of all possible infection pathways. The disease is caused by the xylem-limited bacterium Xylella fastidiosa, which is transmitted by several species of sharpshooters. The objectives of this research were to elucidate the fate of bacteria in planta after inoculations in almond nursery plants and to determine patterns of insect vector population dynamics and temporal distribution of X. fastidiosa–infected plants relative to host plant assemblages in habitats surrounding commercial nurseries. In an experimental nursery, disease incidence was markedly affected by rootstock type. Prior to bud grafting, ‘Nemaguard’ rootstock seedlings were not susceptible to bacterial infection. After bud grafting with a susceptible scion (‘Sonora’), scions were susceptible to infection regardless of rootstock genotype. Surveys near commercial nurseries revealed that only habitats with permanent grass cover sustained vector populations throughout the season. A total of 87 plant samples tested positive for X. fastidiosa (6.3%) using enzyme-linked immunosorbent assay (ELISA), with a higher number of X. fastidiosa–infected plants found in weedy alfalfa fields than in other habitat types. Among plant species infected by X. fastidiosa, 33% were winter annuals, 45% were biennials or perennials, and 22% were summer annuals. Collectively, these findings identified a potential pathway for X. fastidiosa infection of almonds in nursery situations.

scholarly journals Development of a probabilistic early health warning system based on meteorological parameters

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
A. K. Sahai ◽  
Raju Mandal ◽  
Susmitha Joseph ◽  
Shubhayu Saha ◽  
Pradip Awate ◽  
...  
Keyword(s):  
Meteorological Parameters ◽  
Disease Incidence ◽  
Geographical Location ◽  
Warning System ◽  
Maximum Temperature ◽  
Probabilistic Forecasting ◽  
Health Warning ◽  
Probabilistic Forecasts ◽  
Early Health ◽  
Recognition Technique

Abstract Among the other diseases, malaria and diarrhoea have a large disease burden in India, especially among children. Changes in rainfall and temperature patterns likely play a major role in the increased incidence of these diseases across geographical locations. This study proposes a method for probabilistic forecasting of the disease incidences in extended range time scale (2–3 weeks in advance) over India based on an unsupervised pattern recognition technique that uses meteorological parameters as inputs and which can be applied to any geographical location over India. To verify the robustness of this newly developed early warning system, detailed analysis has been made in the incidence of malaria and diarrhoea over two districts of the State of Maharashtra. It is found that the increased probabilities of high (less) rainfall, high (low) minimum temperature and low (moderate) maximum temperature are more (less) conducive for both diseases over these locations, but have different thresholds. With the categorical probabilistic forecasts of disease incidences, this early health warning system is found to be a useful tool with reasonable skill to provide the climate-health outlook about possible disease incidence at least 2 weeks in advance for any location or grid over India.

scholarly journals Tick-Borne Flaviviruses, with a Focus on Powassan Virus

2018 ◽  
Vol 32 (1) ◽  
Author(s):  
Gábor Kemenesi ◽  
Krisztián Bányai
Keyword(s):  
Disease Incidence ◽  
Russian Far East ◽  
Far East ◽  
Case Fatality ◽  
The United States ◽  
Diagnostic Methods ◽  
Control Measures ◽  
Virus Infections ◽  
Vector Population ◽  
Powassan Virus

SUMMARYThe tick-borne pathogen Powassan virus is a rare cause of encephalitis in North America and the Russian Far East. The number of documented cases described since the discovery of Powassan virus in 1958 may be <150, although detection of cases has increased over the past decade. In the United States, the incidence of Powassan virus infections expanded from the estimated 1 case per year prior to 2005 to 10 cases per year during the subsequent decade. The increased detection rate may be associated with several factors, including enhanced surveillance, the availability of improved laboratory diagnostic methods, the expansion of the vector population, and, perhaps, altered human activities that lead to more exposure. Nonetheless, it remains unclear whether Powassan virus is indeed an emerging threat or if enzootic cycles in nature remain more-or-less stable with periodic fluctuations of host and vector population sizes. Despite the low disease incidence, the approximately 10% to 15% case fatality rate of neuroinvasive Powassan virus infection and the temporary or prolonged sequelae in >50% of survivors make Powassan virus a medical concern requiring the attention of public health authorities and clinicians. The medical importance of Powassan virus justifies more research on developing specific and effective treatments and prevention and control measures.

Effect of acid deposition on trichome morphology and dogwood anthracnose biology

1992 ◽  
Vol 50 (1) ◽  
pp. 840-841
Author(s):  
Kyle T. Thornham ◽  
R. Jay Stipes ◽  
Randolph L. Grayson
Keyword(s):  
Acid Deposition ◽  
Disease Incidence ◽  
Natural Populations ◽  
Tree Disease ◽  
Flowering Dogwood ◽  
Discula Destructiva ◽  
Disease Induction ◽  
Dogwood Anthracnose ◽  
Trichome Morphology ◽  
Precipitation Events

Dogwood anthracnose, caused by Discula destructiva (1), is another new catastrophic tree disease that has ravaged natural populations of the flowering dogwood (Cornus florida) in the Appalachians over the past 15 years, and the epidemic is prognosticated to continue (2). An estimated 9.5 million acres have been affected, primarily in the Appalachian Mountains, from VA southwards, alone, and an estimated 50% of all dogwoods in PA have been killed. Since acid deposition has been linked experimentally with disease induction, and since the disease incidence and severity are more pronounced at higher elevations where lower pH precipitation events occur, we investigated the effect of acidic foliar sprays on moiphologic changes in the foliar cuticle and trichomes (3), the initial sites of infection and foci of Discula sporulation.

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