scholarly journals Population dynamics of natural enemies on bt / non bt cotton and their correlation with weather parameters

2017 ◽  
Vol 9 (4) ◽  
pp. 2360-2365 ◽  
Author(s):  
Roomi Rawal ◽  
K. K. Dahiya ◽  
Roshan Lal ◽  
Adesh Kumar
Keyword(s):  
Population Dynamics ◽  
Natural Enemies ◽  
Maximum Temperature ◽  
Adult Plant ◽  
Bt Cotton ◽  
Crop Season ◽  
Cotton Genotypes ◽  
Weather Parameters ◽  
Two Peaks ◽  
Cotton Cultivar

The field study was carried out at Research Farm of cotton section, Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar, India to determine the effect of environmental factors and seven cotton genotypes (Bt and non Bt) on three natural enemies namely chrysoperla, coccinellids beetle and spi-ders. Natural enemies remained active throughout the crop season (with two peaks) with little differences among them. Chrysoperla and coccinellids both were remained active from 25th to 40th SMW (June to October, 2014) while spiders were active from 25th to 41st. It was observed that highest population of Chrysoperla (1.17 eggs/plant) and spiders (1.59 adult/plant) was observed on Bt cotton cultivar namely RCH-134 and JK-1947 respectively. However, coccinellids preferred non Bt genotype (HHH-223) for their population build-up. Chrysoperla and coccinellids popula-tion was significantly negatively correlated with maximum temperature (r = -0.527 at 5% and r = -0.626 at 1% re-spectively); positively correlated with RHm, RHe; negatively correlated with minimum temperature and wind speed without significance. While, spiders population showed negative correlation with all weather parameters except sun-shine hours. It was observed that population of the natural enemies fluctuated under different environmental conditions during cotton season.

scholarly journals Influence of prevailing weather parameters on population dynamics of spotted stem borer, Chilo partellus (Swinhoe) and its natural enemies on maize in Haryana

2021 ◽  
Vol 22 (3) ◽  
pp. 295-304
Author(s):  
GAURAV SINGH ◽  
MAHA SINGH JAGLAN ◽  
TARUN VERMA ◽  
SHIVANI KHOKHAR
Keyword(s):  
Population Dynamics ◽  
Chilo Partellus ◽  
Natural Enemies ◽  
Minimum Temperature ◽  
Significant Positive Correlation ◽  
Maximum Temperature ◽  
Positive Correlation ◽  
Average Maximum ◽  
Weather Parameters ◽  
Average Minimum Temperature

The experiment was conducted at CCS Haryana Agricultural University Regional Research Station, Karnal to ascertain the influence of prevailing meteorological parameters on population dynamics of Chilo partellus and its natural enemies on maize during Kharif, 2017. Maximum oviposition (0.75 egg masses per plant) was recorded during 28th standard meteorological week (SMW) whereas larval population was at peak during 31st SMW (3.8 larvae per plant). Cumulative (47.5%) and fresh plant infestation (11.5%) were maximum during 34th and 28th SMW, respectively. Maximum egg parasitisation (6.53%) by Trichogramma sp. and larval parasitisation (31.64%) by Cotesia flavipes was recorded during 28th and 33rd SMW, respectively. Changes in pest population were correlated and regressed with weather parameters. Egg and larval populations of C. partellus and parasitisation by Trichogramma sp. exhibited significant positive correlation with average minimum temperature whereas C. flavipes exhibited significant negative correlation with average maximum temperature (r = -0.741) and highly significant positive correlation with evening relative humidity (r = 0.695). Plant infestation and dead heart formation were significantly correlated with average minimum temperature and non-significantly correlated with all other weather parameters. The multiple linear regression analysis explained the variability due to various weather parameters. This information can be utilised while formulating integrated management tactics against this pest.

scholarly journals Population dynamics of exotic rugose spiralling whitefly, Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) on coconut as influenced by weather factors and natural enemies

2020 ◽  
pp. 120-125
Author(s):  
K. Elango ◽  
S. Jeyarajan Nelson
Keyword(s):  
Population Dynamics ◽  
Negative Correlation ◽  
Natural Enemies ◽  
Tamil Nadu ◽  
Abiotic Factors ◽  
Climatic Conditions ◽  
Weekly Interval ◽  
Maximum Temperature ◽  
Weather Factors ◽  
Extent Of Damage

The rugose spiralling whitefly, Aleurodicus rugioperculatus Martin is a new exotic pest occurring in several crops including coconut since 2016 in India. Due to variation in the agro-climatic conditions of different regions, arthropods show varying trends in their incidence also in nature and extent of damage to the crop. Besides, abiotic factors also play a key role in determining the incidence and dominance of a particular pest and their natural enemies in a crop ecosystem. The population dynamics of new exotic whitefly species, A. rugioperculatus and their associated natural enemies was assessed on five-year-old Chowghat Orange Dwarf coconut trees at Coconut Farm of Tamil Nadu Agricultural University. The study indicated that RSW was found throughout the year on coconut and the observation recorded on weekly interval basis shows that A. rugioperculatus population escalated from the first week of July 2018 (130.8 nymphs/leaf/frond) reaching the maximum during the first week of October (161.0 nymphs/leaf/frond) which subsequently dwindled to a minimum during April. The parasitisation by E. guadeloupae on RSW ranged from 31.60 percent in Aug. 2018 to 57.60 percent in December 2018. The association of biotic and abiotic factors with A. rugioperculatus population showed a negative correlation with E. guadeloupae and C. montrouzieri. There was a significant positive correlation between maximum temperature and minimum temperature as well as relative humidity. However, rainfall showed a negative correlation with A. rugioperculatus population.

Effect of weather parameters on the population dynamics of White backed planthopper, Sogatella furcifera (Horvath) in rice

2021 ◽  
Vol 58 (1) ◽  
pp. 15-20
Author(s):  
ADVSLP Anand Kumar ◽  
N Mallikharjuna Rao ◽  
CV Rama Rao ◽  
S Krishnam Raju
Keyword(s):  
Population Dynamics ◽  
Andhra Pradesh ◽  
Agricultural Research ◽  
Abiotic Factors ◽  
Research Station ◽  
Sogatella Furcifera ◽  
Correlation Studies ◽  
Weather Parameters ◽  
Two Peaks ◽  
Second Peak

A field experiment on the population dynamics of White backed planthopper (WBPH), Sogatella furcifera (Horvath) carried out during kharif and rabi 2016-17 at Regional Agricultural Research Station, Maruteru, West Godavari District of Andhra Pradesh, India revealed that the incidence of WBPH was observed during 36th SMW (September 3-9). Its activity increased during successive weeks up to 44th SMW with two peaks, first peak at 38th SMW (September 17-23) with population of 46/10 hills and second peak at 42nd SMW (October 15-21) with population of 170/ 10 hills during kharif 2016, while WBPH was first noticed during 7th SMW (February 12-18) and population increased gradually during successive weeks and attained peak number during 13th SMW (March 26-April 1) in rabi 2016-17. Correlation studies revealed that WBPH had significant negative relation with morning relative humidity of current week during kharif 2016. None of the abiotic factors has showed significant relationship with the population of WBPH during rabi 2016-17.

Population dynamics of aphid, Myzus persicae (Sulzer)(Hemiptera: Aphididae) on different Brassica species

2017 ◽  
Author(s):  
Joni Kumar ◽  
Bishwajeet Paul
Keyword(s):  
Population Dynamics ◽  
Abiotic Factors ◽  
Correlation Coefficients ◽  
Brassica Species ◽  
Significant Negative Correlation ◽  
Aphid Population ◽  
Maximum Temperature ◽  
Rabi Season ◽  
Rapid Multiplication ◽  
Weather Parameters

Present studies deal with continuous observation of aphid population on different brassica species at every fourteen days interval. Five plants were selected randomly from each plot. The top 10cm terminal portion was used for counting of aphid population. The first appearance of aphid population was found at end of December in Brassica rapa var toria, B. rapa var yellow sarson and Brassica juncea. The correlation coefficients between aphid population and abiotic factors revealed contradictory results. Except for a few instances the abiotic parameters show a low order of association with aphid population. A significant negative correlation of aphid population was found with maximum temperature in B. rapa var toria (r= -0.963**), B. rapa var yellow sarson (r= -0.877*) and B. juncea (r= -0.913*). The population dynamics study of coccinellid beetles revealed that its population increased gradually with the increase of aphid population and vice-versa. In our experiment none of the weather parameters alone was responsible for the multiplication and growth of the aphid but it is assumed that during major part of rabi season, the meteorological parameters remained conducive for the rapid multiplication of aphid.

scholarly journals Studies on population dynamics of major pests of Ailanthus excelsa Roxb

2021 ◽  
Vol 42 (4(SI)) ◽  
pp. 1168-1173
Author(s):  
V. Manimaran ◽  
◽  
M. Suganthy ◽  
A. Balasubramanian ◽  
P. Pretheepkumar ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Insect Pests ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Pest Population ◽  
Peak Period ◽  
Ailanthus Excelsa ◽  
Major Pest ◽  
Weather Parameters ◽  
R Value

Aim: To study the peak period of incidence of major pest of Ailanthus excelsa. Methodology: Seasonal abundance of major insect pests of A. excelsa viz., ailanthus defoliator and ailanthus webworm were studied in 5-year-old plantation at Forest College and Research Institute, Mettupalayam from April, 2018 to March, 2019. Weekly observations were made on the abundance of major insect and pest population which were correlated with weekly weather parameters. Results: Monitoring the population dynamics of insect pests revealed that the major key pests were ailanthus defoliator and webworm. The highest number of ailanthus defoliator (38.00 larvae per tree) and webworm (33.90 larvae per tree) were recorded during 44th standard week in 5-year-old plantation. Correlation analysis revealed that maximum temperature (Tmax) was negatively correlated with ailanthus defoliator with the r value of -0.299. Regarding webworm, wind velocity and evaporation rate were negatively correlated with the r value of -0.412 and -0.361 and was found to be statistically significant at 1% level. Interpretation: Seasonal abundance of this information helps us to take decision for the management of A. excelsa pests.

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).

Comparative Effectiveness Of Seed Treating And Foliar Insecticides Against Sucking Pests Of Cotton And Impact On Their Natural Enemies

2013 ◽  
Vol 38 (1) ◽  
pp. 61-70 ◽  
Author(s):  
SMA Hossain ◽  
MA Baque ◽  
MR Amin
Keyword(s):  
Natural Enemies ◽  
Untreated Control ◽  
Seed Treatment ◽  
Foliar Spray ◽  
Cost Ratio ◽  
Research Station ◽  
Benefit Cost Ratio ◽  
Benefit Cost ◽  
Thrips Population ◽  
Cotton Cultivar

The Imidacloprid insecticide, Gaucho 70 WS at 1.5, 2.5, 3.5, 4.5 and 5.5 g/kg seed was used as seed treatment and monocrotophos 40 WSC at 1120 ml/ha was applied as foliar spray on CB9 cotton cultivar to suppress aphid, whitefly and thrips, and impact on their natural enemies during 2008-2011 at the Regional Cotton Research Station, Dinajpur, Bangladesh. The activity of natural enemies, such as ladybird beetle, lacewing, syrphid, and spider population on the sucking pests attacking cotton cultivar CB9 and yield of cotton were recorded. Imidacloprid significantly reduced aphid, whitefly, and thrips population on cotton crops compared to untreated control or foliar spray of monocrotophos 40 WSC at 1120 ml/ha. Ladybird beetles, lacewings, syrphids, and spiders were abundant in the field but their population decreased in the treated plots compared to untreated control. The CB9 cotton cultivar produced significantly higher yield (1.73 t/ha) with a benefit cost ratio 12.47 when seeds were treated with Imidacloprid at 5.5 g/kg fuzzy seed. This study indicated that Imidacloprid (Gaucho 70 WS) used as a seed treatment may be suggested to the cotton growers for controlling sucking pests. Bangladesh J. Agril. Res. 38(1): 61-70, March 2013 DOI: http://dx.doi.org/10.3329/bjar.v38i1.15190

Seasonal Incidence of Pulse Aphid (Aphis craccivora Koch.) and its Natural Enemies on Field Pea (Pisum sativum L.) in Relation to Some Abiotic Factors in Alluvial Zone of West Bengal

2021 ◽  
Author(s):  
S. Pal ◽  
S. Samanta ◽  
A. Banerjee
Keyword(s):  
Relative Humidity ◽  
Pisum Sativum ◽  
Natural Enemies ◽  
West Bengal ◽  
Insect Pests ◽  
Field Pea ◽  
Pest Population ◽  
Pisum Sativum L ◽  
Aphis Craccivora Koch ◽  
Weather Parameters

Background: Field pea, Pisum sativum L. is an important winter-season pulse crop. It is subjected to damage by both field and storage insect pests and approximately 10-15 per cent reduction in yield was reported due to the infestation of different insect pests. Among these, pulse aphid (Aphis craccivora Koch.) affects plant physiology directly by removal of nutrients or indirectly by dispersal of various viral diseases. The present investigation has been aimed to study the seasonal fluctuations of aphids and their natural enemies as well as their correlation. Another objective was to know the effect of various weather parameters on pulse aphids and their natural enemies which ultimately would be helpful to develop a forewarning model.Methods: The field experiment was conducted at the A-B Block Farm of Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal using two varieties of field pea (KPMR 935 and IFPD 122) during rabi seasons of two consecutive years of 2017-18 and 2018-19 following a Randomized Block Design with three replications. After recording the total population of both pests (nymphs and adults) and their natural enemies across the season, the mean population was worked out and used for correlation and regression studies along with the weather parameters. Result: Maximum aphid population was noticed during the peak pod formation stage of the crop irrespective of the varieties. The pest population was very strongly correlated with the incidence of coccinellid and ant population in both test varieties. Among the weather parameters, both maximum and minimum temperature and sunshine hour showed a positive correlation with the pest population and their natural enemies but relative humidity and rainfall showed a negative correlation. Regression studies indicated that temperature and relative humidity were the most influencing factors over the incidence of aphid in both the seasons.

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