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.

scholarly journals Seasonal abundance and effect of abiotic factors on mango leaf hopper Amritodus atkinsoni (Leth.) population on wild and different cultivators of mango in Jammu region

2013 ◽  
Vol 14 (3) ◽  
pp. 161-168
Author(s):  
Shakha Sharma ◽  
J.S Tara
Keyword(s):  
Relative Humidity ◽  
Minimum Temperature ◽  
Significant Positive Correlation ◽  
Abiotic Factors ◽  
Agricultural Science ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Leaf Hopper ◽  
Series Of Experiments ◽  
Agricultural Science And Technology

The mango leaf hopper Amritodus atkinsoni (Leth.) is a very serious pest of mango in J&K region. A series of experiments were conducted on seasonal abundance and the influence of abiotic factors on the incidence of A. atkinsoni on wild and different cultivars of mango viz Dashehari, Langra, Malda and Amarpalli  at Sher-e-Kashmir University of Agricultural Science and Technology Jammu, and, at a mango orchard at Nagbani. The mango hoppers (adults) started appearing with the panicle emergence during the months of February-March and reached its peak ranging from 9.6 to 14.2 in wild and all cultivars under study during May-June. After this the hopper population started declining, but showed another peak (6.6 to 9.8) during August-September which is comparatively lower than the previous one. This clearly indicates that the species breeds twice a year thus a bivoltine species. From September onwards, the hoppers went on declining and vanished by the end of December as they migrate to cracks and crevices of tree trunk and overwinter as adults. Abiotic factors such as maximum temperature (X1), minimum temperature (X2), morning relative humidity (X3), evening relative humidity (X4) and rainfall (X5) had much impact on the growth of hopper population. The hopper population correlated negatively and significantly with morning relative humidity (r = -0.635 to - 0.816) and evening relative humidity (r = - 0.289 to - 0.556) and showed a significant positive correlation with mean maximum temperature (r = 0.692 to 0.915) and minimum temperature (r = 0.590 to 0.881) in wild and all four cultivars, whereas rainfall remained fluctuating throughout the study period thus didn’t show any significant impact.

scholarly journals Climatic Factors Affecting The Population Dynamics Of Lentil Aphid In Inner Terai Region Of Nepal

2020 ◽  
Vol 17 (2) ◽  
pp. 155-164
Author(s):  
S Neupane ◽  
S Subedi
Keyword(s):  
Population Dynamics ◽  
Relative Humidity ◽  
Minimum Temperature ◽  
Negative Impact ◽  
Climatic Factors ◽  
Block Design ◽  
Winter Season ◽  
Research Field ◽  
Aphid Population ◽  
Maximum Temperature

Population dynamics of lentil aphid Aphis craccivora (Hemiptera: Aphididae) was assessed in relation with climatic parameters at the research field of National Maize Research Program (NMRP), Rampur, Chitwan during winter season of two consecutive years 2016 to 2018. The experiment was organized in randomized complete block design consisting 20 lentil varieties with three replications. The crop was sown during last week of November in both the years. The daily meteorological parameters like maximum temperature (Tmax), minimum temperature (Tmin), relative humidity (RH) and rainfall (Rf) were recorded at the meteorological station located in NMRP, Rampur, Chitwan and then converted into weekly basis as the standard meteorological week (SMW) with correspondence to weekly population of aphid. The incidence of aphid was started from 2nd SMW of January (2 aphid/plant/10 cm apical twigs) during both experimentation years. Initially the population was low and gradually increased and reached to its peak (49 aphid/plant/10cm apical twigs) on 9th SMW i.e. first week of March with correspondence to weather parameters viz. maximum and minimum temperature (°C), relative humidity (%) and rainfall (mm) were 30.80, 15.34, 67.72 and 0, respectively over the years. The aphid population had significant positive correlation with Tmax (r= 0.94) while the Tmin showed highly significant correlation (r=0.99). The relative humidity (RH) had non significant negative correlation (r= -0.90) and rainfall (Rf) showed non significant negative impact (r= - 0.15) with aphid population. The regression model developed could explain 99% variation in aphid population in different cultivars of lentil. SAARC J. Agri., 17(2): 155-164 (2019)

Surveillance of pea leaf miner (P. horticola) infesting pea (Pisum sativum) in relation with abiotic factors

2019 ◽  
Vol 25 (2) ◽  
Author(s):  
Ram Keval ◽  
H.S. Vanajakshi ◽  
Sunil Verma ◽  
Babli Bagri
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Negative Relationship ◽  
Positive Association ◽  
Leaf Miner ◽  
Maximum Temperature ◽  
Seasonal Incidence ◽  
Sunshine Hours

To study the seasonal incidence of insect pests of pea (P. sativum) the investigation was carried out during Rabi session of 2016-17 and 2017-18, at Agricultural Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi. The incidence of pests infesting pea was recorded from 50th SMW to 11th SMW. During the observation it was found that P. horticola showed its appearance in the field from 1st to 11th SMW with peak population (71% leaf infestation) in 7th SMW. When population was correlated with abiotic factors it was found that there was positive association with maximum temperature (r = 0.759**), minimum temperature (r = 0.672**), wind speed (r = 0.449).and sunshine hours (r =0.583*) whereas a negative relationship was maintained with morning relative humidity (r =-0.496) and evening relative humidity (r=-0.515), during 2016- 17. Similarly, during 2017-18 there was a positive association with maximum temperature (r = 0.360), minimum temperature (r =0.431), wind speed (r = 0.544*) and sunshine hours(r=0.493) whereas a negative relationship was maintained with morning relative humidity (r =-0.277) and evening relative humidity (r=-0.365).

scholarly journals Population Dynamics of Natural Enemies in Okra Agro-ecosystem in Relation to Abiotic Factors

2021 ◽  
pp. 61-69
Author(s):  
Ram Kumar ◽  
P. P. Singh
Keyword(s):  
Relative Humidity ◽  
Natural Enemies ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Maximum Temperature ◽  
College Of Agriculture ◽  
Pooled Data ◽  
Weather Parameters ◽  
The Relationship ◽  
Positive Effect

The present experiment was carried out to access the relationship between population fluctuation of natural enemies and abiotic factors in okra agro-ecosystem at the Research Farm, Tirhut College of Agriculture, Dholi, Muzaffarpur (Bihar). From pooled data of two consecutive Kharif seasons i.e. 2018 and 2019 it was inferred that the highest coccinellids population was registered during 35th standard week (4.56 coccinellids/ 5 plant). Thereafter, the population gradually decreases and reached to 1.19 coccinellids/ 5 plant during 41st standard week i.e. end of the crop. Correlation studies of coccinellids population with abiotic factors indicated that the maximum temperature had positive and highly significant effect on coccinellids. While, minimum temperature and relative humidity at 7 hrs showed positive but non-significant effect on coccinellids. The relative humidity at 14 hrs and rainfall had negative and non-significant correlation with coccinellids population. All the weather parameters together governed 49.90 per cent to the coccinellids population build up (R2 = 0.4990). In case of spider, incidence commenced in 27th standard week however, the maximum population (3.94 spiders/ 5 plant) was observed in 35th standard week. Correlation analysis of spider population with abiotic factors exhibited that the maximum temperature had highly significant and positive effect on spider population. Unlike it, minimum temperature and relative humidity at 7 hrs indicated positive and non-significant effect on spider population. However, the effect of relative humidity at 14 hrs and rainfall on spider population was found negative and non-significant. However, all the prevailing weather parameters together contributed 48.23 per cent towards spider incidence (R2 = 0.4823).

scholarly journals Weather parameters vulnerability on tea production in north western Himalaya, India

2016 ◽  
Vol 8 (4) ◽  
pp. 2262-2267
Author(s):  
Parmod Verma ◽  
Ranbir Singh Rana ◽  
Ramesh Ramesh ◽  
Ranu Pathania
Keyword(s):  
Relative Humidity ◽  
Minimum Temperature ◽  
Positive Relationship ◽  
Western Himalaya ◽  
Green Leaf ◽  
Maximum Temperature ◽  
Leaf Yield ◽  
Tea Production ◽  
Weather Parameters ◽  
June July

The study assessed the sensitivity of weather parameters with respect to total green leaf and two leaves and bud (T & B) productivity of tea crop {Camellia sinensis (L.) Kuntze}. The maximum temperature ranging from 20.0 to 29.0 oC during March, May, August and September showed positive relationship with values ranging from 0.26 to 3.38 and 0.22 to 3.22 for green leaf and T & B yield, respectively. Similarly, minimum temperature ranging from 9.1 to 20.0 oC during March and July to October found positive 0.001 to 2.93 and 0.28 to 2.91 for green leaf and T & B productivity, respectively. The mean monthly rainfall amounting 52.7 to 664.7 mm during March, May, July to October and 52.7 to 488.4 mm during June, July, September and October also showed positive sensitivity with values ranging from 0.03 to 0.33 and 0.007 to 0.35 for green leaf and T & B yield, respectively. The relative humidity ranging between 41.2 to 77.3% during April to May for green leaf yield (0.32 to 1.71) and during April to May and October for two leaf and bud yield (0.00 to 1.70) showed positive relationship. So, maximum and minimum temperature between 20.0 to 29.0 oC and 9.1 to 20.0 oC, respectively with rainfall of 52.7 to 488.4 mm and relative humidity 41.2 to 77.3% are the most beneficial weather parameters for tea cultivation at Palampur conditions.

scholarly journals Evaluation of Future Climate and Potential Impact on Streamflow in the Upper Nan River Basin of Northern Thailand

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Miyuru B. Gunathilake ◽  
Yasasna V. Amaratunga ◽  
Anushka Perera ◽  
Imiya M. Chathuranika ◽  
Anura S. Gunathilake ◽  
...  
Keyword(s):  
River Basin ◽  
Minimum Temperature ◽  
Climate Models ◽  
Hydrological Modeling ◽  
Winter Season ◽  
Future Climate ◽  
Maximum Temperature ◽  
Monthly Precipitation ◽  
Northern Thailand ◽  
The Impact

Water resources in Northern Thailand have been less explored with regard to the impact on hydrology that the future climate would have. For this study, three regional climate models (RCMs) from the Coordinated Regional Downscaling Experiment (CORDEX) of Coupled Model Intercomparison Project 5 (CMIP5) were used to project future climate of the upper Nan River basin. Future climate data of ACCESS_CCAM, MPI_ESM_CCAM, and CNRM_CCAM under Representation Concentration Pathways RCP4.5 and RCP8.5 were bias-corrected by the linear scaling method and subsequently drove the Hydrological Engineering Center-Hydrological Modeling System (HEC-HMS) to simulate future streamflow. This study compared baseline (1988–2005) climate and streamflow values with future time scales during 2020–2039 (2030s), 2040–2069 (2050s), and 2070–2099 (2080s). The upper Nan River basin will become warmer in future with highest increases in the maximum temperature of 3.8°C/year for MPI_ESM and minimum temperature of 3.6°C/year for ACCESS_CCAM under RCP8.5 during 2080s. The magnitude of changes and directions in mean monthly precipitation varies, with the highest increase of 109 mm for ACESSS_CCAM under RCP 4.5 in September and highest decrease of 77 mm in July for CNRM, during 2080s. Average of RCM combinations shows that decreases will be in ranges of −5.5 to −48.9% for annual flows, −31 to −47% for rainy season flows, and −47 to −67% for winter season flows. Increases in summer seasonal flows will be between 14 and 58%. Projection of future temperature levels indicates that higher increases will be during the latter part of the 20th century, and in general, the increases in the minimum temperature will be higher than those in the maximum temperature. The results of this study will be useful for river basin planners and government agencies to develop sustainable water management strategies and adaptation options to offset negative impacts of future changes in climate. In addition, the results will also be valuable for agriculturists and hydropower planners.

scholarly journals Phenological study of congeneric Myrcia species and Clethra scabra in wetland and drained habitats in a Montane Forest

2020 ◽  
Author(s):  
Vinícius Londe ◽  
Jaqueline Alves Pereira ◽  
Hildeberto Caldas de Sousa
Keyword(s):  
Relative Humidity ◽  
Abiotic Factors ◽  
Montane Forest ◽  
The Other ◽  
Maximum Temperature ◽  
Wetland Soil ◽  
Congeneric Species ◽  
Abiotic Conditions ◽  
Local Factors ◽  
The Tropics

Abstract Although important, phenological studies comparing congeneric species or the same species growing in different habitats are still scarce for the tropics. Herein, we integrate phylogeny, ecology and biometeorology to verify whether the phenophases of congeneric species Myrcia laruotteana and Myrcia amazonica or Clethra scabra differ when their populations inhabit wetland and drained habitats and to determine what abiotic factors affect the vegetative and reproductive phenophases of these species in distinct habitat patches. We collected data on phenological events of 80 trees for 1 year in Itacolomi State Park, Brazil, and related them to abiotic local factors. Contrary to our expectation, the phenophases of the congeneric species did not differ between habitats, but the reproductive phenophases of C. scabra did and was greater in drained soil. Phenophases of C. scabra were affected by the depth of the water table and maximum temperature in the wetland soil. Insolation, precipitation, maximum temperature and relative humidity influenced Myrcia and Clethra in the drained soil. The differences between C. scabra populations suggest that this species is phenotypically plastic and can present distinct phenophases depending on the habitat it inhabits. On the other hand, the congeneric Myrcia species may have similar phenophases in distinct habitats because of their shared similarities during their evolution. This study provides a better understanding of the ecology of these species and their adaptations to different abiotic conditions. Data of this nature are important in a changing world and can inform strategies for adaptive management.

scholarly journals SEASONAL FLUCTUATION OF ASIAN CITRUS PSYLLA POPULATIONS IN THE CITRUS ORCHARDS INFECTED WITH HUANGLONGBING IN SARGODHA, PAKISTAN

2017 ◽  
Vol 29 (1) ◽  
pp. 175
Author(s):  
Yasir Iftikhar ◽  
Imran U. Haq ◽  
Waqas Raza ◽  
Muhammad I. Ullah ◽  
Sajjad Ali ◽  
...  
Keyword(s):  
High Temperature ◽  
Environmental Factors ◽  
Minimum Temperature ◽  
Management Strategy ◽  
Integrated Management ◽  
Seasonal Fluctuation ◽  
Diaphorina Citri ◽  
Citrus Production ◽  
Citrus Orchards ◽  
Citrus Psylla

A study on seasonal fluctuation in Citrus psylla (Diaphorina citri) (CP) population in citrus orchards infected with Huanglongbing was carried out in relation to environmental factors in six tehsils of Sargodha district. The population of citrus psylla was reached to the peak twice in a year. Young flushes favored the build-up in psylla population. Minimum temperature and rainfall had highly significant correlation with build-up in population of citrus psylla in all the six tehsils of Sargodha. Although, high temperature also favored the high population of citrus psylla in two tehsils. August and mid-March to April were the two times when population of citrus psylla reached to the peak. Therefore, an integrated management strategy can be formulated with this study that will not only help in reducing the HLB incidence but also increase in citrus production.

scholarly journals Studies on some diseases of fruits and vegetable crops in relation to meteorological parameters

MAUSAM ◽  
2021 ◽  
Vol 51 (3) ◽  
pp. 269-274
Author(s):  
S. V. DATAR ◽  
R. C. DUBEY ◽  
N. CHATTOPADHYAY
Keyword(s):  
Relative Humidity ◽  
Minimum Temperature ◽  
Early Blight ◽  
Meteorological Parameters ◽  
Maximum Temperature ◽  
Vegetable Crops ◽  
Correlation Techniques

The role of different meteorological parameters controlling the incidences of some diseases on tomato, guava and fig grown at Pune and Padegaon in Maharashtra state were studied by graphical superimposition and correlation techniques. Peak infestation of rust on fig was observed in January at Padegaon whereas maximum infestation of fruit canker on guava and early blight on tomato were reported respectively from September to first week of October and September to November at Pune. Increase in maximum temperature was found to increase the infestation of both fruit canker and early blight. Decrease in afternoon relative humidity favoured the infestation of fruit canker and rust. Fall of minimum temperature and rise in bright hours of sunshine also aggravated the incidences of fruit canker and rust respectively.

scholarly journals Future climate uncertainty and spatial variability over Tamilnadu State, India

2015 ◽  
Vol 17 (1) ◽  
pp. 175-185
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Minimum Temperature ◽  
Climate Models ◽  
Regional Climate ◽  
Future Climate ◽  
Maximum Temperature ◽  
Projection Data ◽  
Climate Uncertainty

<div> <p>The present study analyses future climate uncertainty for the 21st century over Tamilnadu state for six weather parameters: solar radiation, maximum temperature, minimum temperature, relative humidity, wind speed and rainfall. The climate projection data was dynamically downscaled using high resolution regional climate models, PRECIS and RegCM4 at 0.22&deg;x0.22&deg; resolution. PRECIS RCM was driven by HadCM3Q ensembles (HQ0, HQ1, HQ3, HQ16) lateral boundary conditions (LBCs) and RegCM4 driven by ECHAM5 LBCs for 130 years (1971-2100). The deviations in weather variables between 2091-2100 decade and the base years (1971-2000) were calculated for all grids of Tamilnadu for ascertaining the uncertainty. These deviations indicated that all model members projected no appreciable difference in relative humidity, wind speed and solar radiation. The temperature (maximum and minimum) however showed a definite increasing trend with 1.8 to 4.0&deg;C and 2.0 to 4.8&deg;C, respectively. The model members for rainfall exhibited a high uncertainty as they projected high negative and positive deviations (-379 to 854 mm). The spatial representation of maximum and minimum temperature indicated a definite rhythm of increment from coastal area to inland. However, variability in projected rainfall was noticed.</p> </div> <p>&nbsp;</p>

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