scholarly journals A record of cannibalism in Ceriagrion coromandelianum Fabricius (Zygoptera: Coengrionidae)

2020 ◽  
Vol 79 (4) ◽  
pp. 44-46
Author(s):  
Arajush Payra
Keyword(s):  
West Bengal ◽  
Winter Season ◽  
Conspecific Male

During winter season on January 12th, 2014, a case of cannibalism in Ceriagrion coromandelianum Fabricius was observed near Bara Solemanpur, village of Purba Medinipur district, West Bengal, India. This is the first instance of cannibalism recorded in C. coromandelianum, where a female devours its conspecific male

scholarly journals Land Situation and Sowing Date Effects Growth and Yield of Crops in the Rice-Pulse Based Cropping Systems of Coastal India

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 152
Author(s):  
Koushik Brahmachari ◽  
Sukamal Sarkar ◽  
Donald S. Gaydon ◽  
Manoj Kumar Nanda ◽  
Argha Ghosh ◽  
...  
Keyword(s):  
West Bengal ◽  
Cropping Systems ◽  
Winter Season ◽  
Cropping System ◽  
Sowing Date ◽  
Growth And Yield ◽  
Limited Area ◽  
Pulse Crops ◽  
Stover Yield ◽  
Saline Zone

The costal saline zone of West Bengal in India is the home for millions of the world’s poorest and most vulnerable people. Due to gradual increase in salt accumulation on soils of the costal saline zone of West Bengal in India from winter to summer days, cultivation of the second crop in winter season becomes possible in a limited area. To address this issue, field experiment was conducted both in rainy and winter seasons of 2016–2017 and 2017–2018 in this zone to study the feasibility of incorporating different winter pulses (lentil and grass pea) in the rice based cropping system. The experiment was conducted in strip plot design having two factors namely, Factor I: Six dates of sowing of rice at an interval of one week (2nd week of June to 3rd week of July) and Factor II: Two land situations (Medium-upland and Medium-lowland). Date of sowing significantly influenced dry matter and macro-nutrients (NPK) partitioning in rice. Irrespective of land situation, crop sown on 1st and 2nd dates recorded significantly higher grain yield and macro-nutrient uptake by rice. Date of sowing of rice and land situation also significantly influenced the seed and stover yield of different pulse crops. Pulse crops sown on 1st and 2nd dates recorded significantly higher seed yield in coastal saline ecology of West Bengal, India.

scholarly journals Annual and seasonal variability of wet day frequency in West Bengal, India

MAUSAM ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. 713-722
Author(s):  
S. G. PATIL ◽  
A. MAJUMDER
Keyword(s):  
Seasonal Variability ◽  
West Bengal ◽  
Winter Season ◽  
Frequency Data ◽  
Parametric Approach ◽  
Statistical Parameters ◽  
Post Monsoon ◽  
Increasing Trend ◽  
Coefficient Of Skewness ◽  
Skewness And Kurtosis

The monthly wet day frequency data of West Bengal for period 1901-2000 were analyzed to know annual and seasonal variability over decades along with annual, pre-monsoon, monsoon, post-monsoon and winter trends. The non-parametric approach (Mann-Kendall) revealed that the most of the districts shows the decreasing trend during monsoon and increasing trend during pre, post monsoon and in winter season. The changes observed in the statistical parameters (mean, SD, coefficient of skewness and kurtosis) during different decades which reflect the changing pattern of wet-day frequency in West Bengal.

scholarly journals Study of winter fog over Indian subcontinent : Climatological perspectives

MAUSAM ◽  
2021 ◽  
Vol 65 (1) ◽  
pp. 19-28
Author(s):  
G.K. SAWAISARJE ◽  
P Khare ◽  
C.Y. SHIRKE ◽  
S. DEEPAKUMAR ◽  
N.M. NARKHEDE
Keyword(s):  
Relative Humidity ◽  
Spatial Variability ◽  
Air Temperature ◽  
West Bengal ◽  
Indian Subcontinent ◽  
Winter Season ◽  
Dew Point ◽  
North India ◽  
Gangetic Plains ◽  
Long Period

Fog is localized phenomenon where horizontal visibility is reduced to less than 1000 m due to suspension of very small water droplets in the air. In fact Fog is cloud at surface level. This phenomenon matters to us in our daily activities due to its effect on life, public health, road safety, and economic prosperity.  Its knowledge is essential to meet critical societal needs. In India, radiation and advection fog are most common which occur mostly over north India in winter. This study presents results of spatial variability of average number of days having visibility less than 1000 m at 0300 UTC during winter season over Indian subcontinent (0° N-35° N and 60° E-100° E) using synoptic hour daily surface data. Analysis of Fog events based on half hourly METAR observations for winter months             (December 2010-February 2011) at selected ICAO stations of India is also presented.    The monthly spatial variability of average number of days with fog having visibility less than 1000 m indicates presence of fog over Indo-Gangetic plains on an average of 7 to 10 days during December and more than 8 days during January. South Gangetic West Bengal is susceptible to fog during February. Seasonal variation of fog shows that there is prominence of fog over Indo-Gangetic plains on an average of more than 6.5 days. Significant incidences of foggy days occur over South Interior Karnataka and Coastal Karnataka has incidence of foggy days on an average of 6.5 days. North India is susceptible to dense fog on average of 2.5 days during the season while Gangetic West Bengal, West Rajasthan and adjoining parts of east Rajasthan and East Uttar Pradesh have occurrence of fog on an average of 3.5 days. Thick fog occurs on an average of 3 days over northern India during the winter season. Analysis of time series of air temperature, dew point temperature, dew point depression, visibility, zonal and meridional components of wind and its magnitude at selected ICAO stations indicate that visibility reduces to below 1000 m while light winds are southeasterly at Ahmedabad, northerly to northwesterly at Amritsar, northerly to northeasterly at New Delhi, westerly to southwesterly at Kolkata, Guwahati and dew point depression is below 3 °C during such conditions. Long period 1971-2010 analysis of visibility conditions less than 1000 m over Indian subcontinent shows Indo-Gangetic plains region to have average wind speed to be 0.6 m/s, air temperature in the range 9 °C to 15 °C during December-February at 0300 UTC. Long period 1971- 2010 analysis of relative humidity shows Indo-Genetic plains region to have relative humidity in the range 72% to 84% at 0300 UTC during December-February.

scholarly journals Cultivation of Berseem (Trifolium alexandrinum) and Oats (Avena sativa) Fodder Crops by Using Biofertilizers and Biopesticide: An Experience from Farmers’ Field in Nadia District of West Bengal

2021 ◽  
Vol 12 (3) ◽  
pp. 211-215
Author(s):  
Asif Mohammad ◽  
◽  
Anupam Chatterjee ◽  
Keyword(s):  
Crop Production ◽  
West Bengal ◽  
Soil Health ◽  
Winter Season ◽  
Animal Husbandry ◽  
Chemical Fertilizers ◽  
Fodder Crop ◽  
Fodder Quality ◽  
Fodder Production ◽  
Fodder Crops

Indiscriminate and unscientific application of chemical fertilizers and pesticides, adversely affect the agricultural production system by damaging soil health, contaminating natural water bodies and ground water. As a result of prolonged use of excessive chemical fertilizers and pesticides, the yield of field crops are decreasing due to poor soil health and produced crops also adversely impact human health. For animal husbandry enterprise, fodder production is one of the major activities. Injudicious use of chemicals can reduce fodder production as well as productivity of livestock can also be reduced. Under these circumstances, demonstration of fodder berseem and oats cultivation by using biofertilizers and biopesticides were carried out in farmer’s field at three blocks of Nadia district of West Bengal, India. The study was conducted in the winter season of the year 2020-21; the selected farmers were trained and method demonstrations of fodder crop production were carried out. The demonstration results suggested that average yield of berseem fodder crop was 53.33±2.80 t ha-1 whereas oats fodder crop was 43.07±2.16 t ha-1. The BC ratio of fodder crop cultivation suggested that, by the cultivation of both fodder crops farmers got substantial economic return. Fodder produced by the using biofertilizers and biopesticide contain good amount of dry matter as well as crude protein. From the study it can be concluded that both the fodder crops can be grown in the farmers’ field of the study area by using the biofertilizers and biopesticide without deteriorating the fodder yield and fodder quality.

scholarly journals Studies of some aspects of rodent ecology in the four districts of the gangetic plain of West Bengal, India

1970 ◽  
Vol 27 ◽  
pp. 85-90 ◽  
Author(s):  
Lalyan Brata Santra ◽  
Chanchal Kumar Manna
Keyword(s):  
West Bengal ◽  
Rattus Rattus ◽  
Winter Season ◽  
Late Winter ◽  
Gangetic Plain ◽  
Norway Rat ◽  
Clear Cut ◽  
Mole Rat ◽  
Average Litter Size ◽  
Field Rodents

This study has been conducted in four Districts (i.e., Nadia, North 24-Parganas, Hooghly and Burdwan) of the Gangetic plain of West Bengal, India. The results of the present study indicate that these Districts are badly infested by various types of rodents. Among them wild Indian house rat (Rattus rattus) is quite preponderant followed by field mice (Mus musculus), Norway rat (Rattus norvegicus) and Indian mole rat (Bandicota sp). Percentage of the female individual of these species is higher than the male individual. They cause severe types of damages in the fields and houses. In the District Nadia, Hooghly, North 24-Parganas and Burdwan, paddy and potato were damaged and estimated during the study period. Other crops and vegetables such as wheat, gourd, cauliflower, cabbage and jute were also damaged by the rodents. Household properties e.g., books, clothes, utensils and electronic goods were also destroyed by the rats. Damages were maximum in the mud built houses. They build their nest and burrows in the upland, trees and periphery of the field but extensive damages were noticed in the centre of the field. Rodents breed throughout the year but peak breeding seasons are August to October and late winter season and average litter size is about 6 to 8. The present study also points out the migratory behavior, hoarding materials in the burrows, nature of damages in relation to field conditions. For the control operation of the rodents and especially the rats, it is essential to have a clear-cut idea about the species present in the area, their habit and habitat, mode of burrowing, their movements, preference of food and a detailed life history of predominant rodent species. These aspects have been thoroughly studied in the present investigation. Key words: Gangetic plain, West Bengal, rodents, Rattus rattus, paddy, burrow.    doi:10.3329/ujzru.v27i0.1961 Univ. j. zool. Rajshahi Univ. Vol. 27, 2008 pp. 85-90

scholarly journals Rainfall trend analysis and its future projection over Gangetic West Bengal (GWB) region of India during post-monsoon and winter season

2016 ◽  
Vol 8 (3) ◽  
pp. 1152-1156 ◽  
Author(s):  
Pramiti Kumar Chakraborty ◽  
Lalu Das
Keyword(s):  
Trend Analysis ◽  
West Bengal ◽  
Winter Season ◽  
Policy Formulation ◽  
Rainfall Data ◽  
Future Projection ◽  
Short Term ◽  
Winter Rainfall ◽  
Post Monsoon ◽  
Increasing Trend

Studying the variability of rainfall and its future projection during post-monsoon and winter season is important for providing the information to the farmers regarding crop planning. For evaluating rainfall scenario, long (1901-2005) and short term (1961-2005 and 1991-2005) rainfall data of nine selected IMD stations of South Bengalwas collected and subdivided into 30 year period up to 1990 and a 15 year period from 1991 to 2005. The data were subjected to trend analysis and available GCM data were compared with the observed rainfall data. The postmonsoon and winter rainfall changes during 1901-2005 were positive (except Krishnangar, -47.67 mm) and negative (except Alipore and Berhampur) respectively. During 1991-2005 all the stations recorded a positive change during post-monsoon, while reverse was true for winter. Among the different GCMs, INGV-ECHM4 estimated the postmonsoon rainfall at the best, whereas winter rainfall successfully estimated by MIROC-Hi. Future projection of both post-monsoon and winter rainfall over the region showed an increasing trend. This will help in policy formulation for water management in agriculture.

scholarly journals Occurrence and diversity of microalgae in phytoplankton collected from freshwater community ponds of Hooghly District, West Bengal, India

2019 ◽  
Vol 6 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Papiya Halder ◽  
Manojit Debnath ◽  
Samit Ray
Keyword(s):  
Light Intensity ◽  
West Bengal ◽  
Diversity Index ◽  
Winter Season ◽  
Late Summer ◽  
Diversity Indices ◽  
Chemical Parameters ◽  
Wiener Diversity Index ◽  
Physico Chemical ◽  
Multiple Variables

A study on diversity, seasonal occurrence, distribution percentage of microalgal taxa and physico-chemical parameters of five community ponds, located in Chinsurah town, Hooghly district of West Bengal, has been carried out. Correlation between occurrence of microalgal genera and some parameters of environment, physico-chemical nature of natural water bodies were explored by Canonical Correspondence Analysis (CCA). Diversity indices have been calculated using PAST software program. A total of 23 microalgal taxa belonging to four algal classes were recorded and the study indicated that the microalgal diversity vary with variation in physico-chemical parameters of water and light intensity. Out of these genera, occurrence of Chodatella sp. in late summer and Tetrallantos sp. and Synechocystis sp. in winter season were specific. In CCA, multiple variables (dissolved oxygen, water temperature, electrical conductivity, pH, light intensity and inorganic phosphorous) played a significant role in occurrence of microalgal taxa. Observation concluded that the Chlorophycean members were dominant throughout the study period and the Shannon–Wiener diversity index was highest for a site with large number of Chlorophycean member. This study will help in future to assess water quality.

scholarly journals Study of Limnological Status of Two Selected Floodplain Wetlands of West Bengal

2021 ◽  
Author(s):  
Golam Ziauddin
Keyword(s):  
Dissolved Oxygen ◽  
Physicochemical Parameters ◽  
West Bengal ◽  
Winter Season ◽  
Trophic Levels ◽  
Healthy Population ◽  
Floodplain Wetlands ◽  
Secchi Disc ◽  
Physico Chemical ◽  
The Status

Abstract Limnology is the study of all aquatic systems, both lentic and lotic fresh, fresh, and saline including lakes, wetlands, marshes, bogs, ponds, reservoirs, streams, rivers, oceans, etc. about their physical, chemical, and biological characteristics. Among this phytoplankton, Zooplankton, periphyton, benthos are a minute aquatic free-floating microscopic organism, which acts as a larger food source of larval and higher vertebrates and invertebrates including carnivorous and omnivorous fishes. They are related to the growth of juvenile fishes and are also play important role in the transfer of energy from the primary phytoplankton to higher trophic levels. The plankton community fluctuates according to the physicochemical parameters and the relative environment of the water body especially the Rotifers as they are known to change immediately along with the change in water quality . Realizing the importance of floodplain wetlands and the paucity of literature on the limnology of this ecosystem present investigation was carried out in two floodplain wetlands having characteristics of open (Kole beel, an ox-bow lake formed near Somra Bazar in Hooghly district), and closed beel Suguna beel situated in Nadia District of West Bengal) system during the period 2011–2013. The physicochemical parameters of the investigated beels' water and soil were, for the most part, favorable for planktonic development. It has an alkaline pH of 7.5–8.4 and is alkaline. The dissolved oxygen content and Secchi Disc transparency values indicate that the water is in excellent condition. The water was moderately hard, with only trace amounts of nutrients present. Seasonal fluctuations in the water column were apparent, and they were mainly attributable to replenished supplies and volume. The plankton population of the studied ecosystem was made up of a mixed and healthy population of diverse fauna. The greatest diversity was observed during the winter season, when favorable temperature, dissolved oxygen, and other physicochemical parameters of water, as well as optimal solar penetration, coincided. In a closed system (Suguna), the richness of planktonic structure resulted in higher fish production (1570.05 kg/ha/yr) than in an open system (Kole) (384.4 kg/ha/yr). The status of floodplain wetlands was determined to be eutrophic based on various Physico-chemical and biological parameters.

scholarly journals Growth, Yield, Seed and Seedling Quality Parameters of Rapeseed-mustard Varieties under Different Seed Priming Options

2020 ◽  
pp. 1-14
Author(s):  
Rupa Das ◽  
Saikat Biswas ◽  
Utpal Biswas ◽  
Amitava Dutta
Keyword(s):  
Seed Yield ◽  
West Bengal ◽  
Laboratory Data ◽  
Winter Season ◽  
Growth Yield ◽  
Seed Priming ◽  
Quality Parameters ◽  
Seedling Quality ◽  
Growth And Yield ◽  
Peg 6000

Rationale: Crop production and quality of produce get affected by drought, stand establishment and low availability of nutrients. Apart from various prevailing methods, seed treatment through priming now-a-days has been found to noticeably improve crop establishment for increasing seed yield and quality. Aim: To study the effect of various seed priming options on rapeseed-mustard varieties. Place of Study: A field experiment was conducted at AB Block Farm, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia, West Bengal, India during winter season of 2017-2018. Methodology: Experiment comprised six rapeseed-mustard varieties (Anushka, Sanchita, TBM-143,TBM-204, Kranti and Pusa Bold) in main plot and five seed priming options (KH2PO4 @ 0.15 mol 100 ml water-1 5 g seeds-1, KNO3 @ 0.1 mol 100 ml water-1 5 g seeds-1, PEG 6000 @ -0.3 MPa 100 ml water-1 5 g seeds-1, hydro priming @ 100 ml 5 g seeds-1 and control) in subplot, replicated thrice in a split plot design. Observations on growth and yield contributing parameters were recorded from the field. Further, various quality parameters of seed and seedlings were evaluated in the laboratory. Data on all the parameters were finally statistically analyzed. Results: Among the varieties, Pusa Bold performed better in terms of growth, yield contributing parameters and seed yield under seed priming through either KH2PO4 @ 0.15 mol 100 ml water-1 5 g seeds-1 or PEG 6000 @ -0.3 MPa 100 ml water-1 5 g seeds-1. Seed and seedling quality parameters such as root and shoot lengths, seedling fresh and dry weights, germination % and vigour index were also improved under the same. Conclusion: Cultivation of mustard variety, Pusa Bold by seed priming through any of those two chemicals (KH2PO4 or PEG 6000) can be recommended for New alluvial zone of West Bengal, India.

scholarly journals A relative study of diversity of endophytic fungi in a Lianas Butea superba from Belpahari and their seasonal variation

2020 ◽  
Vol 23 ◽  
pp. 27-34
Author(s):  
Biplab Bagchi ◽  
Keyword(s):  
Endophytic Fungi ◽  
Forest Floor ◽  
West Bengal ◽  
Fungal Endophytes ◽  
Winter Season ◽  
Nutrient Contents ◽  
Leaf Petiole ◽  
Determining Factors ◽  
Fusarium Sp ◽  
Butea Superba

Fungal endophytes from Butea superba were studied collecting from Belpahari of Jhargram district of West Bengal during three seasons-winter, summer and monsoon. A total of 159 plant tissue segments were resided by endophytic fungi among 225 tissue segments and endophytic fungi of the number of 201 were isolated from 159 various tisue specimens such as leaf, petiole and stem. The fungal isolates belong to the genera as many as 25, along with 5 unidentified fungi and few sterile mycelia. Beltrania sp., Lasiodiplodia sp., Fusarium sp., Penicillium sp., Pestalotiopsis sp. were found most commonly and dominantly found out of all isolates. Majority of the endophytic isolates were during winter season and least in summer. Colonization frequencies in winter, summer and monsoon are 73.33%, 60% and 78.66% respectively. This difference in CF % might be due to variation of moisture content in various seasons inside it and variation of absorbable nutrient contents in forest floor. It has been observed that microenvironment and microclimate were determining factors for assuring endophytic biodiversity.

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