Seasonal abundance of Campoletis chlorideae Uchida (Hymenoptera:Ichneumonidae), A larval parasitoid of Helicoverpa armigera(Hubner) hardwick in chickpea

2016 ◽  
Vol 39 (4) ◽  
Author(s):  
A. Kuzhandhaivel Pillai ◽  
S. Selvaraj ◽  
Meena Agnihotri
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Significant Negative Correlation ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Weather Factors ◽  
Campoletis Chlorideae ◽  
Minimum Relative Humidity ◽  
Larval Parasitoid ◽  
Survival And Development

Climate change is likely to affect the insect host and the activity and abundance of biological control agents. Therefore, the present studies were conducted to understand the seasonal abundance of larval parasitoid, Campoletis chlorideae on chickpea at Pantnagar during the cropping season 2010-11 and 2011-12 revealed that the larval parasitoid exhibited its marked first appearance in 3rd standard meteorological week (SMW) and attained peak population in 7th (85.80%) and 8th (87.65%) SMW, respectively. Statistical analysis between the weather parameters and the population of the larval parasitoid showed a significant negative correlation with maximum temperature (r= - 0.698* and r= - 0.705*) and minimum temperature (r= - 0.706* and r= - 0.790*) whereas significant positive correlation with maximum relative humidity (r= 0.800** and r = 0.824**) and minimum relative humidity (r= 0.636* and r= 0.254) during 2010-11 and 2011-12, respectively. The results indicated that changes in weather factors as a result of climate change would have considerable influence on survival and development of C.chlorideae.

Impact of Abiotic Factors and Dates of Sowing on Helicoverpa armigera (Hübner) Parasitoid Campoletis chloridae (Uchida) under Chickpea Cropping System in Tarai Region of Uttarakhand

2021 ◽  
Author(s):  
S.D. Divija ◽  
Meena Agnihotri
Keyword(s):  
Helicoverpa Armigera ◽  
Abiotic Factors ◽  
Cropping System ◽  
Weather Factors ◽  
Campoletis Chlorideae ◽  
Minimum Relative Humidity ◽  
Larval Parasitoid ◽  
Helicoverpa Armígera ◽  
The Impact ◽  
Helicoverpa Armigera Hubner

Background: The solitary endo-larval parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) is an important biocontrol agent of H. armigera in chickpea ecosystem. Abiotic factors are likely to affect the insect host and activity of its parasitoid. Therefore, the present study was conducted to understand the impact of weather factors and different dates of sowing on per cent parasitization of Helicoverpa armigera (Hübner) by Campoletis chlorideae (Uchida) in chickpea ecosystem.Methods: In this field-laboratory investigation were carried out at Pantnagar during the cropping season of 2017-18. Twenty-five larvae of H. armigera (first and second instars) were collected randomly at weekly basis from untreated chickpea crop. In the laboratory, the collected larvae were reared till parasitoid emergence and observed for per cent parasitisation. Result: The observation recorded revealed that mean seasonal parasitism by Campoletis on larvae of H. armigera was found to be 21%, 43.5% and 34.5% in early (20th October), normal (11th November) and late sown crop (1st December), respectively. Various abiotic parameters like maximum and minimum temperature, maximum and minimum relative humidity registered high level of significant association with per cent parasitization in early and normal sown crop compared to the low level of association in late sown crop. The multiple regression analysis showed that the combined effect of all the meteorological parameters were responsible for 90%, 57.9% and 30.5% variation in per cent parasitization in early, normal and late sown crop, respectively.

scholarly journals Weather Factors Associated with Development of Sorghum Ergot in the Texas Panhandle

Plant Disease ◽  
2006 ◽  
Vol 90 (6) ◽  
pp. 717-722 ◽  
Author(s):  
F. Workneh ◽  
C. M. Rush
Keyword(s):  
Relative Humidity ◽  
Weather Conditions ◽  
Maximum Temperature ◽  
Hybrid Seed Production ◽  
Weather Factors ◽  
Inoculum Level ◽  
Minimum Relative Humidity ◽  
Hourly Temperature ◽  
Texas Panhandle ◽  
Claviceps Africana

Since its first introduction in 1997, sorghum ergot, caused by Claviceps africana, has been observed yearly in the Texas Panhandle, where it has caused occasional epidemics in hybrid-seed production fields. To determine the effect of weather factors on ergot severity, inoculation experiments were conducted in 2003 and 2004 using sequentially planted sorghum plants. Sorghum flowers were inoculated with three inoculum concentrations (1 × 104, 1 × 105, or 1 × 106 spores/ml) prepared from infected sorghum panicles producing fresh honeydew. Each year, inoculations were conducted several times during sorghum flowering periods so that time of inoculations would coincide with different weather conditions. Weather variables (temperature, relative humidity, wind speed, precipitation, and radiation) were collected using an onsite weather station. Infected and uninfected florets were counted 8 to 13 days after inoculation, and the percentage of infected florets per sorghum panicle (severity) was determined. In both years, temperature and relative humidity were the predominant factors responsible for variations in sorghum ergot severity with all inoculum densities. Relationship between ergot severity and each of the two variables depended on inoculum density. Measurable infection occurred at a maximum temperature of 34°C with 1 × 106 spores/ml, while there was little or no infection at 30°C with 1 × 104 spore/ml. Cumulative departures from minimum relative humidity and maximum temperature infection thresholds 12, 18, 24, 36, 48, and 72 h after inoculation were calculated and regressed against ergot severity for each inoculum level. Cumulative departures of hourly temperature and relative humidity from maximum temperature and minimum relative humidity infection thresholds 18 and 24 h after inoculation were best related to sorghum ergot severity (R 2 = 89 and 91; P < 0001, respectively). Models based on these two time-durations then were used in predicting a regional site-specific ergot severity potential using radar-estimated rainfall.

scholarly journals Influence of weather factors, soil temperature and moisture on collar rot disease of betel vine (Piper betle L.) under coastal saline zone of West Bengal

2021 ◽  
Vol 23 (4) ◽  
pp. 428-434
Author(s):  
PRABIR KUMAR GARAIN ◽  
BHOLANATH MONDAL ◽  
SUBRATA DUTTA
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Soil Temperature ◽  
Disease Incidence ◽  
Maximum Temperature ◽  
Piper Betle ◽  
Weather Factors ◽  
Collar Rot ◽  
Minimum Relative Humidity ◽  
Rot Disease

A study was conducted to find out the influence of weather factors, soil temperature and soil moisture on the incidence of Sclerotium rolfsii Sacc. induced collar rot disease in betelvine (Piper betle L.), during 2016 to 2018. Fourteen soil and weather factors, taken from the agrometeorological observatory located at instructional farm of Ramkrishna Ashram Krishi Vigyan Kendra, Nimpith and recorded from a nearby betelvine boroj, were subjected to multiple regression, binary logistic regression and canonical discriminant analysis to develop a suitable disease forewarning model. The binary logistic model, Y(0/1) = 5.899 + 0.865 (Tmax) – 0.569 (SM) + 0.097 (BRHmin) was able to predict the disease risk with 78 per cent accuracy and correctly classified 94 per cent of cases during model validation in 2018. The weekly averages of maximum temperature (Tmax), soil moisture (SM) and minimum relative humidity inside the boroj (BRHmin) were found to be the most significant predictors of disease incidence, in this model. The soil moisture at 69 - 72 per cent of field capacity, minimum temperature of 25 - 27oC, maximum temperature of 33 - 36oC, average soil temperature of 28 - 30oC, minimum relative humidity of 60 - 72 per cent inside the boroj and maximum relative humidity of 83 - 89 per cent inside the boroj were found to be highly congenial for collar rot disease incidence in betelvine under coastal saline zone of West Bengal.

scholarly journals Impact of abiotic factors on build-up of citrus psylla, Diaphorina citri Kuwayama population in Punjab, India

2014 ◽  
Vol 6 (2) ◽  
pp. 371-376 ◽  
Author(s):  
Hijam S. Devi ◽  
D. R. Sharma
Keyword(s):  
Relative Humidity ◽  
Disease Transmission ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Winter Season ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Weak Links ◽  
Diaphorina Citri ◽  
Citrus Psylla

Seasonal abundance of citrus psylla (Diaphorina citri) Kuwayama was studied on Kinnow mandarin under Punjab conditions during 2012 and 2013. Population of D. citri was present throughout the year but only adults found surviving during December and February. There was no nymphal population when maximum temperature was > 39°C or < 7°C. Two population peaks of nymphs wer e observed, first in April-May and second in August- September. Thereafter, there was abrupt decline in nymphal population during June and July during both the years when the weather conditions i.e. maximum, minimum temperature (°C), relative humidity (%), rainfall (m m) and sunshine (hrs) ranged from 24.4-44, 22.4-31.8, 25.5-100, 0-108.0 and 0-13.5, respectively. Highest peaks of adult were found during May followed by June. With the decrease in temperature from the end of September, the population of D. citri started to decrease and reached its lowest during winter season. Correlation analysis for both the years indicated that maximum and minimum temperature, sunshine and rainfall were positively correlated with nymphal, adult and mixed population but the effect of rainfall on adult population was non-significant, while relative humidity was negatively correlated. The study is useful to find out the weak links of psyllid populations in relation to abiotic factors and that could be exploited to curb its infestation and disease transmission.

Assessment of the future climate potential for tourism over Europe using a combination of downscaling approaches and quantitative impact models

2020 ◽  
Author(s):  
Maria Francisca Cardell ◽  
Arnau Amengual ◽  
Romualdo Romero
Keyword(s):  
Climate Change ◽  
Wind Speed ◽  
Relative Humidity ◽  
Future Climate ◽  
Cumulative Distribution ◽  
Maximum Temperature ◽  
Model Errors ◽  
Present Climate ◽  
Ensemble Strategy ◽  
The Future

&lt;p&gt;Europe and particularly, the Mediterranean countries, are among the most visited tourist destinations worldwide, while it is also recognized as one of the most sensitive regions to climate change. Climate is a key resource and even a limiting factor for many types of tourism. Owing to climate change, modified patterns of atmospheric variables such as temperature, rainfall, relative humidity, hours of sunshine and wind speed will likely affect the suitability of the European destinations for certain outdoor leisure activities.&lt;/p&gt;&lt;p&gt;Perspectives on the future of second-generation climate indices for tourism (CIT) that depend on thermal, aesthetic and physical facets are derived using model projected daily atmospheric data and present climate &amp;#8220;observations&amp;#8221;. Specifically, daily series of 2-m maximum temperature, accumulated precipitation, 2-m relative humidity, mean cloud cover and 10-m wind speed from ERA-5 reanalysis are used to derive the present climate potential. For projections, the same daily variables have been obtained from a set of regional climate models (RCMs) included in the European CORDEX project, considering the rcp8.5 future emissions scenario. The adoption of a multi-model ensemble strategy allows quantifying the uncertainties arising from the model errors and the GCM-derived boundary conditions. To properly derive CITs at local scale, a quantile&amp;#8211;quantile adjustment has been applied to the simulated regional scenarios. The method detects changes in the continuous CIT cumulative distribution functions (CDFs) between the recent past and successive time slices of the simulated climate and applies these changes, once calibrated, to the observed CDFs.&amp;#160;&lt;/p&gt;&lt;p&gt;Assessments on the future climate potential for several types of tourist activities in Europe (i.e., sun, sea and sand (3S) tourism, cycling, cultural, football, golf, nautical and hiking) will be presented by applying suitable quantitative indicators of CIT evolutions adapted to regional contexts. It is expected that such kind of information will ultimately benefit the design of mitigation and adaptation strategies of the tourist sector.&lt;/p&gt;

scholarly journals Determination of relative contribution of different meteorological elements on evaporation

MAUSAM ◽  
2021 ◽  
Vol 50 (4) ◽  
pp. 365-374
Author(s):  
A. CHOWDHURY ◽  
H. P. DAS ◽  
S. D. GAIKWAD
Keyword(s):  
Relative Humidity ◽  
Surface Wind ◽  
Maximum Temperature ◽  
New Delhi ◽  
Regression Equations ◽  
Weather Factors ◽  
Relative Contribution ◽  
Daily Data ◽  
Radiation Maximum ◽  
June July

The present study deals with influence of radiation, maximum temperature, hours of bright sunshine, relative humidity and surface wind on evaporation at Calcutta, Pune and New Delhi. Daily data from 1991-94 of January, May, June, July and October have been utilized. Direct and indirect influence of the weather factors have been determined through "path analysis" and discussed. Multiple regression equations have also been developed with evaporation as the dependent variable and the above five weather parameters as independent variables.   The results reveal that radiation and maximum temperature are the two most important parameters which enhance evaporation. Most of their effect is direct though in some cases their interaction with relative humidity or wind also contribute significantly to evaporation. Humidity and surface wind, generally, do not significantly contribute directly to evaporation; their effect is manifested through interaction with maximum temperature, indirectly.

scholarly journals Investigation of Climate Change Anomaly by Using Nonparametric Test for Navsari District of South Gujarat

2021 ◽  
Vol 9 (3) ◽  
pp. 266-275
Author(s):  
Neeraj Kumar ◽  
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Relative Humidity ◽  
Nonparametric Test ◽  
Maximum Temperature ◽  
Rainfall Trend ◽  
Regression Slope ◽  
Sunshine Hours ◽  
Increasing Trend ◽  
Daily Sunshine

Navsari district of rainfall was shows highest increasing rainfall trend obtained September and negative January, July, October, November and December. The regression slope of the yearly time series is about 12.35 mm/36 years. Maximum temperature shows the highest increasing trend in month October, followed by December and August. The month highest decreasing trend was noticed that January, followed by February and July. The regression slope of the yearly time series is about 0.025°C/36 years. Minimum temperature highest values of the slope (0.109°C/36 year) with high value of regression Slope of determination (0.111°C), the annual Kendall’s tau statistic (0.492°C/36 year), the Kendall Score (310). All the month January to December shows increasing trend. The highest increasing trend found that November, followed by March and July, respectively. This finding shows that all the month shows increasing trend with the range between 0.308°C to 0.390°C. In case of RH-I the highest increasing trend shows September, followed by April and June. Similarly decreasing trend was found that January, followed by February and October, respectively. Relative humidity-II increasing trend was found only at the September month 0.084%, the increasing trend was detected in January to August and October to December, respectively. The strongest trend in the Bright sunshine hour’s decline of all month’s average daily sunshine hours was for the Navsari district. No significant trends were detected in all months and seasons for all weather elements. A similar trend was found in Sen’s slope and regression slope all the months for all the weather elements.

scholarly journals Classificação e Análises das Indicações de Mudanças Climáticas no Município de Sobral - Ceará (Classification and Analysis of Indications of Climate Change in the City of Sobral – Ceará)

2012 ◽  
Vol 4 (5) ◽  
pp. 1056
Author(s):  
Raimundo Mainar Medeiros ◽  
Paulo Roberto Megna Francisco ◽  
Alexandra Lima Tavares
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Water Balance ◽  
Potential Evapotranspiration ◽  
Temperature Fluctuations ◽  
Maximum Temperature ◽  
Temperature Variations ◽  
Meteorological Elements ◽  
The City

A partir das séries climatológicas normais de 1931-1960 e 1961-1990 dos elementos meteorológicos realizaram-se os cálculos do balanço hídrico climatológico, a classificação e as análises das indicações de mudanças climáticas no município de Sobral, estado do Ceará, utilizando O programa do BHnorm  elaborado em planilhas eletrônicas no pacote Excel por Sentelhas et al. (1999) e a metodologia de cálculo do Balanço Hídrico Climático de Thornthwaite & Mather (1955) e a classificação de Thornthwaite (1955), com o objetivo de contribuir para a sustentabilidade do homem no campo. Identificou-se que o clima da área de estudo classifica-se como Megatérmico semiárido e o tipo climático passou do tipo dw2w2d’ para dw2Dd’ com reduções da temperatura mínima e com oscilações de -0,1 a -0,8ºC e temperatura máxima com variações de -1,7 à 2,1ºC.  A umidade relativa do ar ocorreu flutuações positivas de 0,3 à 3,4%. A evapotranspiração potencial oscilou em -71,0 mm em relação aos períodos para o mês de outubro. Os índices de umidade; aridez e hídricos demonstraram valores de 28,6%, -23,9% e -47,5%, respectivamente. Observou-se que todas estas variabilidades ocorreram devido aos efeitos causados pelo homem na estrutura da cidade. Palavras-chave: Meteorologia. Balanço Hídrico Climático. Clima.  Classification and Analysis of Indications of Climate Change in the City of Sobral – Ceará  ABSTRACTFrom the series 1931-1960 climatological normal from 1961-1990 and meteorological elements were carried out calculations of the climatic water balance, classification and analysis of the indications of climate change in the city of Sobral, Ceará State, using the program BHnorm prepared in Excel spreadsheets in the package by Sentelhas et al. (1999) and the methodology of calculation of the Climatic Water Balance of Thornthwaite & Mather (1955) and the classification of Thornthwaite (1955), in order to contribute to the sustainability of the man in the field. It was found that the climate of the study area is classified as megathermal semiarid climate and the type has type dw2w2d 'to dw2Dd' with reductions in the minimum temperature fluctuations and from -0.1 to -0.8 º C and maximum temperature variations with 2.1 to -1.7 ° C. The relative humidity was positive fluctuations of 0.3 to 3.4%. The potential evapotranspiration fluctuated -71.0 mm for the periods for the month of October. The contents of moisture, drought and water showed values ​​of 28.6% -23.9% and -47.5%, respectively. It was observed that all these effects occurred due to variability caused by man in the structure of the city.  Keywords: Meteorology. Climatic Water Balance. Climate.

Occurrence and Pest Severity of Whitefly on Different Varieties of Chili

2021 ◽  
Vol 24 (1) ◽  
pp. 127-135
Author(s):  
M Nasrin ◽  
MR Amin ◽  
MRU Miah ◽  
AM Akanda ◽  
GM Miah
Keyword(s):  
Relative Humidity ◽  
Virus Infection ◽  
Meteorological Parameters ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Abundance Distribution ◽  
Flowering Stage ◽  
Capsicum Spp ◽  
Major Pest ◽  
Peak Abundance

Seasonal abundance, distribution and pest severity of white fly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) were studied on the chili (Capsicum spp.) varieties namely BARI Morich 1, BARI Morich 2, BARI Morich 3, BINA Morich 1 and Bogura Morich during November 2017 to June 2018 at Gazipur in Bangladesh. Results showed that the white fly started to build up their population from 2nd week of February on the chili varieties and exerted the peak abundance at the last week of February when the plants were at flowering stage. Abundances of white fly positively correlated with maximum temperature and relative humidity, and negatively correlated with minimum temperature and rainfall. Meteorological parameters predicted 11.6 to 32.9% abundance of whitefly on the chili varieties. Occurrence of white fly on different strata of the varieties was statistically low on BARI Morich 2 compared to other varieties. Virus infection levels among the varieties differed significantly and BARI Morich 2 showed the lowest level of infection. BARI Morich 2, Bogura Morich and BARI Morich 1 revealed low level of leaf curl indices (6.8 to 9.3%) and these varieties could be selected for cultivation in the areas where whitefly is a major pest of chili. Ann. Bangladesh Agric. (2020) 24(1) : 127-135

scholarly journals Influence of weather factors on the abundance and population dynamics of Spodoptera litura F. and Pieris brassicae L. on cabbage

2017 ◽  
Vol 15 (1) ◽  
pp. 13-21
Author(s):  
MMH Khan ◽  
S Talukder
Keyword(s):  
Population Dynamics ◽  
Relative Humidity ◽  
Negative Correlation ◽  
Spodoptera Litura ◽  
Pieris Brassicae ◽  
Strong Positive Correlation ◽  
Weather Factors ◽  
Larval Population ◽  
Strong Negative Correlation ◽  
Minimum Relative Humidity

In order to study the influence of weather factors on the abundance and population dynamics of Spodoptera litura F. and Pieris brassicae L. on cabbage, a field experiment was conducted. Larval population of S. litura ranged from 0.56 to 1.57 larvae/plant during 8 January to 12 February 2014 crop season while the highest peak was on 5 February 2014 (1.57 larvae/plant) at 29.5 0C temperature. In case of Pieris brassicae, larval population ranged from 0.58 to1.98 larvae/plant and the highest peak of P. brassicae was also on 5 February. The highest peak was on 5 February 2014 at 96% and 38% relative humidity of both maximum and minimum categories and the highest peak of P. brassicae was on 5 February. There was a strong positive correlation (r = 0.824 and r = 0.920) between population of Spodoptera litura and temperature (maximum and minimum). On the other hand, there was a negative correlation (r = -0.439) between population of S. litura and maximum relative humidity and a strong negative correlation (r = - 0.716) between population of S. litura and minimum relative humidity. The population of Pieris brassicae was positively correlated (r = 0.899 and r = 0.956) with maximum and minimum temperatures. There was a negative correlation (r = -0.443) between population of P. brassicae and maximum relative humidity and a strong negative correlation (r = - 0.645) between population of P. brassicae and minimum relative humidity.SAARC J. Agri., 15(1): 13-21 (2017)

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