scholarly journals Abundance, damage severity and management of guava mealybug, ferrisia virgata ckll

2019 ◽  
Vol 16 (2) ◽  
pp. 73-82
Author(s):  
MMH Khan
Keyword(s):  
Relative Humidity ◽  
Leaf Area ◽  
Negative Correlation ◽  
Untreated Control ◽  
Soap Solution ◽  
Maximum Temperature ◽  
Water Spray ◽  
Positive Correlation ◽  
Middle Leaf ◽  
Percent Mortality

The research was carried out to know the abundance and damage severity of mealybug on sarupkathi variety of guava and to evaluate the efficacy of jet powder and Fighter 2.5EC for suppressing populations of mealybug during January to October 2014. Results revealed that the highest number of guava mealybug was observed on middle leaf (42/leaf) while the lowest number was on lower leaf (13/leaf). The highest percent leaf area covered by mealybug was found on middle leaf (78%) while the lowest was on fruit (18%). Maximum temperature and relative humidity had a positive correlation on the mealybug population while the rainfall showed a negative correlation. The highest percent mortality was observed in T2 treatment (Jet powder applied @ 5.0 g L-1 of water) at 24 HAT (hours after treatment) (86.05%) and 48 HAT (93.83%), respectively. At 72 HAT, the highest percent mortality was observed T3 treatment (Jet powder applied @ 7.5 g L-1 of water). In case of insecticidal control, the highest percent mortality was observed in T2 (100%) and T3 (100%) treatments, respectively followed by T1 (98.03%) at 24 HAT. Similar trends were also observed among all treatments at 48 HAT and 72 HAT, respectively. No significant differences were found among three doses of Fighter 2.5EC. The lowest percent mortality of mealybug population was found in T4 (Water spray forcibly) at 24 HAT, 48 HAT and 72 HAT, respectively. No mortality was recorded in untreated control at different HAT in both application of soap solution and insecticides. SAARC J. Agri., 16(2): 73-82 (2018)

scholarly journals Reproductive performance of spiralling whitefly on guava and impact of weather parameters on its immature stages

2018 ◽  
Vol 15 (2) ◽  
pp. 207-214
Author(s):  
I Hossain ◽  
MMH Khan ◽  
SMH Jahan
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Reproductive Performance ◽  
Significant Positive Correlation ◽  
Instar Nymph ◽  
Maximum Temperature ◽  
Immature Stages ◽  
Positive Correlation ◽  
Aleurodicus Dispersus ◽  
Weather Parameters

The study was conducted to know the reproductive performance of spiralling whitefly on guava. Number of colony, eggs, 1st instar, 2nd instar, 3rd instar and 4th instar nymphs per five leaves ranged from 6 to 15, 8 to 32, 0 to 44, 0 to 22, 0 to 45 and 0 to 28, respectively. Maximum number of adults and nymphs were found in the month of January. Highest longevity of Aleurodicus dispersus (21.5 days) was recorded in adult while the lowest was in 2nd instar nymph (6.4 days). The number of colony/leaf and number of 3rd and 4th instar nymphs of A. dispersus had significant positive correlation with minimum and maximum temperature while non-significant positive correlation is observed between the number of egg/colony, the number 1st and 2nd instar nymphs with minimum and maximum temperature. A. dispersus showed nonsignificant positive correlation with minimum and maximum relative humidity regarding number of colony/leaf, 2nd instar nymph while nonsignificant negative correlation with 4th instar nymph.SAARC J. Agri., 15(2): 207-214 (2017)

scholarly journals Influence of Abiotic Factors on Population of Aphid Complex and Its Coexisting Natural Enemies in Mustard Agroecosystem

2021 ◽  
pp. 150-154
Author(s):  
Somala Karthik ◽  
U. Mukherjee
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Natural Enemies ◽  
Abiotic Factors ◽  
Maximum Temperature ◽  
Peak Activity ◽  
Rabi Season ◽  
Mustard Aphid ◽  
Positive Correlation ◽  
Syrphid Larvae

A field experiment was conducted to determine the population build-up of mustard aphid and their natural enemies in relation to abiotic factors at TCA, Dholi during the Rabi season of 2018-19 and 2019-20 respectively. The incidence of mustard aphid started in the 2nd and 3rd SMW of 2019 and 2020 respectively and reached maximum in 8th SMW in both the years. However, the predatory activity of coccinellids, syrphid larvae and spiders were started from 3rd SW with their peak activity at 3rd and 4th week of February in both the years. Mustard aphid population exhibited positive correlation with maximum temperature (0.347 & 0.543), minimum temperature (0.317 & 0.152) and negative correlation with relative humidity (-0.083 & -0.479) during 2019 & 2020 respectively and rainfall (-0.35) during 2020. However, natural enemies viz., coccinellids, syrphid larvae and spiders exhibited positive correlation with Tmax, Tmin, rainfall and negative correlation with RH in both the years.

Impact of abiotic factors on seasonal incidence of insect pests of soybean

2016 ◽  
Author(s):  
R. K. Kalyan ◽  
O. P. Ameta
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Positive Impact ◽  
Significant Negative Correlation ◽  
Maximum Temperature ◽  
Larval Population ◽  
Positive Correlation ◽  
Pod Borer ◽  
Rain Fall ◽  
Tobacco Caterpillar

The study was carried out at Agricultural Research Station- Banswara during kharif-2012 and 2013. During the years 2012 and 2013, the peak population of white fly was observed in the 35th SMW and 37th SMW, respectively. The population of whitefly had a positive correlation with the maximum temperature and sunshine (hours) while, negative correlation with rain fall and morning and evening relative humidity during both the years but significant only during 2013. The maximum population of semilooper was recorded in the 36th SMW and 39th SMW, respectively. The semilooper exhibited a significant and positive correlation with minimum temperature, morning evening humidity and rain fall during both the years. The highest girdle beetle damage was recorded in the 35th SMW and 37th SMW, respectively; whereas the maximum incidence of gram pod borer was recorded in the 36th SMW and 39th SMW, respectively. The larval population of gram pod borer exhibited a significant negative correlation with sun shine and minimum temperature during experimental period; whereas, it exhibited a significant and positive correlation with rainfall and relative humidity during both the years. The maximum incidence of tobacco caterpillar in soybean crop was recorded during 41st SMW and 42nd SMW, respectively. The maximum temperature and sun shine hours showed a significant positive correlation with the larval population of tobacco caterpillar while, significant negative correlation with rainfall during both the years. The regression equation indicated that rainfall had significant negative and positive impact on population of white fly and semilooper, respectively. Whereas, maximum temperature had significant positive impact on population of tobacco caterpillar while rainfall had significant negative effect.

scholarly journals Meteorological parameter anomalies and anomalous radio propagation over Nigeria

2020 ◽  
Vol 9 (1) ◽  
pp. 34-50
Author(s):  
I. Emmanuel ◽  
K.D. Adedayo ◽  
B. Adeyemi ◽  
O.S. Ojo
Keyword(s):  
Spatial Distribution ◽  
Relative Humidity ◽  
Negative Correlation ◽  
Meteorological Parameter ◽  
Radio Propagation ◽  
Monthly Variation ◽  
Wet Season ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Seasonal Movement

Distribution and variation of anomalous radio propagation, temperature and relative humidity anomalies were obtained and analyzed using six years (2010-2015) Era interim data. Seasonal spatial distribution of refractivity gradient and its components were analyzed. The result showed that about 90% of wet component contributed to the variation of refractivity gradient. Highest range of refractivity gradients and its wet components were obtained during the wet season. The result of correlation between ducting occurrence and temperature showed strong negative correlation except in Lagos where positive correlation of 3% was observed. However, positive correlation which ranges between 39% and 70% exist between duct occurrence and relative humidity except in Lagos in Nigeria. Refractivity gradients, relative humidity anomaly and temperature experience a monthly variation. These variations can be attributed to the seasonal movement of inter-tropical discontinuity (ITD) across Nigeria. Keywords: anomalous, anomaly, correlation, ITD

scholarly journals Influence of prevailing weather parameters on population dynamics of fruit borer, Helicoverpa armigera (Hübner) on tomato in Haryana

2021 ◽  
Vol 21 (2) ◽  
pp. 193-196
Author(s):  
SHIVANI KHOKHAR ◽  
KRISHNA ROLANIA ◽  
GAURAV SINGH ◽  
ANIL KUMAR
Keyword(s):  
Relative Humidity ◽  
Helicoverpa Armigera ◽  
Significant Positive Correlation ◽  
Linear Regression Analysis ◽  
Maximum Temperature ◽  
Population Fluctuations ◽  
Larval Population ◽  
Positive Correlation ◽  
Helicoverpa Armígera ◽  
Weather Parameters

A field experiment was conducted for two years (2016-17 and 2017-18) at Entomological Research Area, Department of Entomology, CCS Haryana Agricultural University, Hisar to ascertain the influence of various meteorological parameters on population fluctuations of Helicoverpa armigera on tomato. The maximum oviposition (4.60 eggs/ plant) was recorded during 15th standard meteorologicalweek (SMW) whereas larval population was at peak (4.91 larvae/ plant) during 16th SMW. The larval population showed significant positive correlation with maximum temperature (r=0.617*) and highly significant negative correlation with morning (r=-0.784**) as well as evening relative humidity (r=-0.814**). Maximum eggs parasitization (12.85 %) by Trichogramma sp. was recorded during 16th SMW. These trichogrammatid parasitoids exhibited non-significant correlation with weather parameters and highly significant positive correlation (r=0.976**) with egg counts of H. armigera. Multiple linear regression analysis showed that 77 per cent (R2=0.77) variability in larval population was accounted by weather parameters particularly maximum temperature, morning and evening relative humidity. 

scholarly journals Relationship between Weather Parameters and Incidence of Gram Pod Borer, Helicoverpa armigera on Chickpea

2021 ◽  
Author(s):  
Keshav Mehra ◽  
Veer Singh
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Significant Positive Correlation ◽  
Significant Negative Correlation ◽  
Larval Population ◽  
Positive Correlation ◽  
Minimum Relative Humidity ◽  
Pod Borer ◽  
Sunshine Hours ◽  
Weather Parameters

Background: Chickpea, Cicer arietinum which is considered as a “King of pulses” get adversely affected by several biotic and abiotic stresses, out of which gram pod borer, Helicoverpa armigera (Hübner) is the major one. The damage caused by H. armigera starts from vegetative growth and continues till maturity of the crop. This pest is causes 25 to 70 per cent pod damage in chickpea but in favorable conditions pod damage goes upto 95 per cent. Methods: Present study was carried out during, rabi, 2014-15 and 2015-16 at Research Farm, College of Agriculture, Bikaner (Rajasthan). Correlation coefficient was worked out with weather parameters such as temperature (maximum and minimum), relative humidity (maximum and minimum), rainfall and sunshine hours. Multiple linear forms of regression model were also used to assess the effect of the weather parameters on the incidence of pod borer. Result: The studies revealed that peak larval population of gram pod borer was recorded in the second fortnight of February thereafter, population declined abruptly. The larval population of pod borer on chickpea occurred low at vegetative and flowering stages and high at pod formation as well as at grain developmental stages. The temperature (maximum and minimum) and sunshine hours had significant positive correlation with larval population during rabi, 2015-16. The maximum relative humidity showed significant negative correlation during rabi, 2015-16 whereas, minimum relative humidity showed significant negative correlation with larval population during both the seasons. The rainfall showed significant positive correlation during rabi, 2014-15.

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 Effects of environmental factors on population dynamics of rice earhead bug and their management with newer insecticide combinations and sole insecticide

2019 ◽  
Vol 48 (4) ◽  
pp. 973-979
Author(s):  
Kamal Ravi Sharma ◽  
S.V.S. Raju ◽  
D. Rakshith Roshan
Keyword(s):  
Population Dynamics ◽  
Relative Humidity ◽  
Environmental Factors ◽  
Correlation Analysis ◽  
Negative Correlation ◽  
Untreated Control ◽  
Significant Negative Correlation ◽  
Average Temperature ◽  
Average Relative Humidity ◽  
Weather Parameters

An experiment was conducted to study the population dynamics of rice earhead bug and to evaluate the efficacy of newer insecticide combinations and sole insecticide along with untreated control. The rice earhead bug population was first recorded on 36th standard week as 1 nos./10 sweep nets and peak population (17 nos./10 sweep nets) was observed during 44th standard week. The correlation analysis revealed that rice earhead bug showed significant negative correlation with rainfall while the remaining weather parameters like average relative humidity and average temperature were found negative and non-significantly correlated. The overall data of efficacy revealed that all insecticidal treatments were significantly superior over untreated control. However, the plots treated with fipronil 5% + buprofezin 20% SC recorded the lowest number of rice earhead bug population (2.10 and 3.51 nos./5 sweep nets) after first and second insecticidal sprays, respectively, followed by indoxacarb 10% + thiamethoxam 10% WG (2.47 and 4.25 nos./5 sweep nets, respectively). Whereas, application of thiamethoxam 25% WG and buprofezin 25% singly SC were recorded as third and fourth best treatments, respectively.

scholarly journals WEATHER PARAMETERS AFFECTING THE POPULATION DYNAMICS OF LEAF FOLDER AND POD BORERS ON MUNGBEAN

2020 ◽  
Vol 5 (1) ◽  
pp. 36-40
Author(s):  
Kazi Nazrul Islam ◽  
Md. Mahbubul Islam ◽  
Dr. Md. Mohasin Hussain Khan
Keyword(s):  
Population Dynamics ◽  
Relative Humidity ◽  
Negative Correlation ◽  
Insect Pests ◽  
Population Mobility ◽  
Positive Correlation ◽  
Pod Borer ◽  
Legume Pod Borer ◽  
Weather Parameters

The experiment was conducted to know the abundance of major insect pests on 15 mungbean varieties viz., BARI Mung-1, BARI Mung-2, BARI Mung-3, BARI Mung-4, BARI Mung-5, BARI Mung-6, BINA Moog-4, BINA Moog-5, BINA Moog-6, BINA Moog-7, BINA Moog-8, BU Mug-1, BU Mug-2, BU Mug-4 and Patuakhali local Mung and the role of weather parameters on the population mobility of insects at the farmer’s field of sadar upazila of Patuakhali district, Bangladesh during late Robi season 2016. Variety BARI Mung-4 had the lowest number of leaf folder while variety BARI Mung-6 had the highest number of leaf folder indicating higher susceptibility to leaf folder. Variety BARI Mung-4 had the lowest number of gram pod borer and BARI Mung- 6 had the highest abundance of gram pod borer followed by BINA Moog-7. Variety BINA Moog-4 had the lowest number of legume pod borer and BARI Mung-6 had the highest abundance of legume pod borer followed by BINA Moog-7. Population of leaf folder showed a negative correlation (R2= -0.020) with temperature. Similarly, gram pod borer (R2= -0.317) and legume pod borer (R2= -0.014) showed a negative correlation with temperature. In case of relative humidity, population of leaf folder (R2= -0.175) showed a negative correlation while gram pod borer showed a positive correlation (R2= 0.031) but legume pod borer (R2= -0.086) showed a negative correlation.

scholarly journals Effect of canopy relative humidity on growth and yield of pigeonpea + kalmegh intercropping system

2021 ◽  
Vol 17 (2) ◽  
pp. 442-445
Author(s):  
J. P. Bholane ◽  
V. M. Bhale
Keyword(s):  
Relative Humidity ◽  
Field Experiment ◽  
Grain Yield ◽  
Seed Yield ◽  
Negative Correlation ◽  
Dry Matter ◽  
Growth And Yield ◽  
System Effect ◽  
Positive Correlation ◽  
Herbage Yield

A field experiment was conducted at Nagarjun Medicinal Garden, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during 2009-10 to determine suitable row proportion for pigeonpea + kalmegh intercropping system. Effect of weather parameter such as canopy relative humidity on growth and yield of pigeonpea and kalmegh was studied. Further, canopy relative humidity showed decreasing pattern with the advancement in age of the crop. In pigeonpea maximum morning canopy relative humidity was observed with 2:1 row proportions, however evening canopy relative humidity was maximum with 2:2 row proportion. Dry matter and grain yield of pigeonpea showed positive and negative correlation with morning and evening canopy relative humidity, respectively. While herbage yield, seed yield and andrographoloide yield of kalmegh reported negative and positive correlation with morning and evening canopy relative humidity, respectively.

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