Comparative studies of mymarid diversity from three different zones of paddy ecosystem in Tamil Nadu, India

ENTOMON ◽  
2019 ◽  
Vol 44 (3) ◽  
pp. 173-182 ◽  
Author(s):  
J. Alfred Daniel ◽  
K. Ramaraju ◽  
A. Rameshkumar
Keyword(s):  
Tamil Nadu ◽  
Wiener Index ◽  
Diversity Indices ◽  
Alpha And Beta Diversity ◽  
High Rainfall ◽  
Paddy Ecosystem ◽  
Species Similarity ◽  
Western Zone ◽  
Cauvery Delta ◽  
Rice Ecosystem

Surveys were conducted to explore the mymarid fauna from three different rice growing zones viz., western zone, Cauvery delta zone and high rainfall zone in Tamil Nadu during 2015-16. In the present study, 92 mymarid parasitoids comprising of 8 species under 7 genera viz., Anagrus sp., Anaphes sp., Camptoptera sp., Dicopus longipes (Subba Rao), Lymaenon delhiensis Narayanan and Subba Rao, Lymaenon munnarus Mani and Saraswat, Mymar pulchellum Curtis and Ptilomymar dictyon Hayat and Anis were collected. Alpha and beta diversity were computed for the three zones and the diversity indices (Simpson’s index, Shannon-Wiener index, Pielou’s index) revealed high rainfall zone as the most diverse zone, while Cauvery delta zone being the least diverse. Dicopus longipes is found to the predominant species in rice ecosystem. Jaccard’s index of species similarity comparison revealed 42.5 per cent similarity between western and Cauvery delta zones and 62.5 per cent similarity between high rainfall and Cauvery delta zones and 62.5 per cent similarity between high rainfall and western zones. Correspondence analysis and Bray-curtis cluster analysis were also done to understand the diversity assemblage of the mymarids that were collected.

Collecting parasitic Aculeata (Hymenoptera) from rice ecosystems of Tamil Nadu, India

2020 ◽  
Vol 12 (8) ◽  
pp. 15828-15834
Author(s):  
J. Alfred Daniel ◽  
K. Ramaraju
Keyword(s):  
Beta Diversity ◽  
Tamil Nadu ◽  
Wiener Index ◽  
Diversity Indices ◽  
Alpha And Beta Diversity ◽  
High Rainfall ◽  
Rice Ecosystems ◽  
Western Zone ◽  
Cauvery Delta

Surveys were conducted to explore the parasitic aculeate fauna in rice ecosystems of Tamil Nadu in 2015–2016 in three different rice growing zones, viz., the western zone, the Cauvery delta zone and the high rainfall zone.  The study recorded a total of 32 aculeates that represent 12 species under seven families belonging to three super families, viz., Apoidea (Apidae), Chrysidoidea (Bethylidae, Chrysididae, & Dryinidae), and Vespoidea (Mutillidae, Scoliidae, & Thiphiidae).  Alpha and beta diversity were computed for the three zones and the diversity indices (Simpson’s index, Shannon-Wiener index, Pielou’s index) revealed the high rainfall zone as the most diverse zone, with the Cauvery delta zone being the least diverse.  On comparing the species similarities using the Jaccard’s index in between the three zones taken in pairs, it was found that 42 per cent similarity existed between the western and Cauvery delta zone and 11 per cent similarity between high rainfall and Cauvery delta zones and 16 per cent similarity between the high rainfall and western zones.

scholarly journals Diversity of parasitic Hymenoptera in three rice-growing tracts of Tamil Nadu, India

2019 ◽  
Vol 11 (13) ◽  
pp. 14681-14690
Author(s):  
Johnson Alfred Daniel ◽  
Kunchithapatham Ramaraju
Keyword(s):  
Species Diversity ◽  
Tamil Nadu ◽  
Pairwise Comparison ◽  
Vital Role ◽  
High Rainfall ◽  
Parasitic Hymenoptera ◽  
Rice Ecosystems ◽  
Species Similarity ◽  
Western Zone ◽  
Cauvery Delta

Parasitic hymenoptera play a vital role in rice ecosystems as biocontrol agents of pests.  Surveys were conducted from August 2015 to January 2016 in three rice growing zones in Tamil Nadu: western zone, Cauvery Delta zone, and high rainfall zone.  A total of 3,151 parasitic hymenoptera were collected, of which 1,349 were collected from high rainfall zone, 1,082 from western zone, and 720 from Cauvery Delta zone.  Platygastridae, Ichneumonidae, and Braconidae were the most abundant families in all the three zones.  The species diversity, richness, evenness as well as beta diversity were computed for all three zones via Simpson’s, Shannon-Wiener and Margalef indices.  The results showed the high rainfall zone to be the most diverse and the Cauvery Delta zone the least diverse, but with more evenness.  Pairwise comparison of zones using Jaccard’s index showed 75–79% species similarity. 

scholarly journals Weed management practices in direct seeded rice ecosystem in north western zone of Tamil Nadu

2019 ◽  
Vol 20 (3) ◽  
pp. 145-151
Author(s):  
C. Sivakumar ◽  
◽  
A. Krishnaveni ◽  
M. Pandiyan ◽  
◽  
...  
Keyword(s):  
Weed Management ◽  
Tamil Nadu ◽  
Management Practices ◽  
Direct Seeded ◽  
Western Zone ◽  
Rice Ecosystem ◽  
North Western

scholarly journals FLORISTIC STUDY ON ANGIOSPERMS SURROUNDING THE MEDAVAKKAM LAKE, CHENGALPATTU DISTRICT, TAMIL NADU, INDIA

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Amzad Basha Kolar ◽  
Palanivel. S, ◽  
M. Sheik Noor Mohamed ◽  
S. Sheik Mohamed ◽  
M. Shareef Khan ◽  
...  
Keyword(s):  
Native Species ◽  
Tamil Nadu ◽  
Diversity Index ◽  
Species Abundance ◽  
Wiener Index ◽  
Diversity Indices ◽  
Economic Importance ◽  
The Family ◽  
Species Diversity Indices

Biodiversity plays a significant role in maintaining the ecosystem for their sustainable utilization. A preliminary survey was conducted to document the diversity and economic importance of the angiosperms around the Medavakkam Lake, Chengalpattu district, Tamil Nadu. The study area act as a seed bank for native species and provide suitable conditions to endemic and certain endangered species. Diversity indices of the study area was found significant, in which the species abundance, richness and evenness were found. A total of 71 species belonging to 36 families of angiosperms were documented. Among which the Dicotyledons plants were 87.32% and monocotyledon plants were 12.67% of total flora reported. The study area was dominated by the family fabaceae (14.1%) with ten species. Habit wise classification of plants reveal that trees are predominant with 32%, followed by hers (25%), Shrubs (21%), Climbers (13%), undershrubs (6%) and grasses (3%). The Simpson Diversity Index, Shannon Wiener Index and evenness index of the study area is 0.777, 1.5634 and 0.8725 respectively. These plants was found with enormous benefits to the mankind such as medicinal, edible, timber, ornamental, oil and other sources. This investigation divulges that the Medavakkam Lake has substantial angiosperm diversity served as major source for native plants having greater economic importance.

Yield variability in rainfed crops as influenced by climate variables

2015 ◽  
Vol 7 (4) ◽  
pp. 442-459 ◽  
Author(s):  
Surendran Arumugam ◽  
Ashok K.R. ◽  
Suren N. Kulshreshtha. ◽  
Isaac Vellangany ◽  
Ramu Govindasamy
Keyword(s):  
Climate Change ◽  
Crop Yield ◽  
Tamil Nadu ◽  
Yield Function ◽  
Content Type ◽  
Southern Zone ◽  
Impact Of Climate Change ◽  
Western Zone ◽  
Cauvery Delta ◽  
The Impact

Purpose – This paper aims to explore the impact of climate change on yields and yield variances in major rainfed crops and measure possible changes in yields under projected climate changes in different agro-climatic zones of Tamil Nadu, India. Although many empirical studies report the influence of climate change on crop yield, only few address the effect on yield variances. Even in such cases, the reported yield variances were obtained through simulation studies rather than from actual observations. In this context, the present study analyzes the impact of climate change on crops yield and yield variance using the observed yields. Design/methodology/approach – The Just-Pope yield function (1978) is used to analyze the impact of climate change on mean yield and variance. The estimated coefficient from Just-Pope yield function and the projected climatic data for the year 2030 are incorporated to capture the projected changes in crop yield and variances. Findings – By the year 2030, the yield of pulses is estimated to decline in all the zones (Northeast, Northwest, Western, Cauvery delta, South and Southern zones), with significant declines in the Northeast zone (6.07 per cent), Cauvery delta zone (3.55 per cent) and South zone (3.54 per cent). Sorghum yield may suffer more in Western zone (2.63 per cent), Southern zone (1.92 per cent) and Northeast zone (1.62 per cent). Moreover, the yield of spiked millet is more likely to decrease in the Southern zone (1.39 per cent), Northeast zone (1.21 per cent) and Cauvery delta zone (0.24 per cent), and the yield of cotton may also decline in the Northeast zone (12.99 per cent), Northwest zone (8.05 per cent) and Western zone (2.10 per cent) of Tamil Nadu, India. Originality/value – The study recommends introducing appropriate crop insurance policies to address possible financial losses to the farmers. Prioritizing area-specific stress-tolerant crop varieties without complementing yield would sustain crops cultivation further.

Natural parasitism of eggs of yellow stem borer, Scirpophaga incertulas Walker (Lepidoptera: Crambidae) in rice ecosystem at Tiruchirappalli, Tamil Nadu

ENTOMON ◽  
2020 ◽  
Vol 45 (3) ◽  
pp. 181-188
Author(s):  
T. Sharmitha ◽  
C. Gailce Leo Justin ◽  
S. Sheeba Joyce Roseleen ◽  
P. Yasodha
Keyword(s):  
Field Study ◽  
Tamil Nadu ◽  
Host Density ◽  
Stem Borer ◽  
Scirpophaga Incertulas ◽  
Egg Masses ◽  
Yellow Stem Borer ◽  
Rice Ecosystem ◽  
Natural Parasitism

Three species of parasitoids viz., Telenomus dignus Gahan, Trichogramma japonicum, Ishii and Tetrastichus schoenobii Ferriere were recorded from the egg masses of rice yellow stem borer, Scirpophaga incertulas (Walker) in a field study. The extent of parasitism was high during Rabi (43.33 – 93.33 %) and low during Kharif (0 - 40.00 %). Parasitism by T. dignus was maximum in October (50.00 %), T. japonicum, in November (23.08 %) and T. schoenobii in February (55.55 %). dignus and T. schoenobii in combination parasitized maximum number of egg masses (41.82 %). Multiple parasitism by the three species was high in December (8.33 %) and January (7.14%). Parasitic potential was maximum, when T. schoenobii alone parasitised the egg masses followed by T. dignus and T. schoenobii in combination. Host density in the field influenced the extent of parasitism.

Yield and quality evaluation of ginger (Zingiber officinale Rosc) genotypes under high rainfall zone of Tamil Nadu

1970 ◽  
pp. 95
Author(s):  
R Balakumbahan ◽  
J P Joshua
Keyword(s):  
Tamil Nadu ◽  
Quality Evaluation ◽  
Zingiber Officinale ◽  
Fibre Content ◽  
Research Station ◽  
Local Strains ◽  
High Rainfall ◽  
Yield And Quality ◽  
Rainfall Region ◽  
Horticultural Research

An experiment on ginger was undertaken between April 2012 to March 2015 at Horticultural Research Station, Pechiparai with an objective to identify suitable ginger cultivar or accession with higher yield and quality attributes suitable for high rainfall zone of Tamil Nadu. Twenty four ginger genotypes, local strains and varieties were collected from different ginger growing tracts of India and evaluated for their performance in high rainfall region. Among the twenty four genotypes tested, the accession Z. O- 4 recorded higher fresh rhizome yield (22.16 ha-1) than other genotypes whereas Z. O - 6 recorded highest dry recovery per cent (22.47%). Higher oleoresin and fibre content was recorded in genotypes Z. O – 5 (9.56%) and Z . O – 17 (11.20%) respectively. 

Evolving appropriate zinc fertilization strategy for rice-rice (Oryza sativa) cropping system in Cauvery Delta Zone

2019 ◽  
Vol 56 (3) ◽  
pp. 294-304
Author(s):  
C Sharmila Rahale
Keyword(s):  
Oryza Sativa ◽  
Tamil Nadu ◽  
Field Experiments ◽  
Foliar Spray ◽  
Cropping System ◽  
Green Leaf ◽  
Farm Yard Manure ◽  
Zinc Fertilization ◽  
Initiation Stage ◽  
Cauvery Delta

Six field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai to evolve suitable zinc fertilization method for rice - rice (Oryza sativa L.) cropping system in Cauvery delta zone. The treatment includes: T1 : Control, T2 : 100 g zinc sulphate (ZnSO4)/cent in nursery alone., T3 : root dipping alone in 2 % zinc oxide (ZnO) solution, T4 : 25 kg ZnSO4 ha-1, T5 : 37.5 kg ZnSO4 ha-1, T6 : 25 kg ZnSO4 ha-1+ Farm Yard Manure (FYM) 12.5 t ha-1, T7 : 25 kg ZnSO4 ha-1 + Green Leaf Manure (GLM) 6.5 t ha-1, T8 : Tamil Nadu Agricultural University Micro Nutrient (TNAU MN) mixture 25 kg ha-1 as Enriched Farm Yard Manure (EFYM), T9 : TNAU MN mixture 37.5 kg ha-1 as EFYM, T10 : Foliar spray of 0.5% ZnSO4 + 1 % urea at tillering and panicle initiation stage, T11 : 100g ZnSO4 /cent in nursery alone + Foliar spray of 0.5 % ZnSO4 + 1 % urea at tillering and panicle initiation stage (T2+ T10), T12 : root dipping alone in 2 % ZnO solution + Foliar spray of 0.5 % ZnSO4 + 1 % urea at tillering and panicle initiation stage (T3 + T10), T13: 100 g ZnSO4 /cent in nursery alone + root dipping alone in 2 % ZnO solution + Foliar spray of 0.5 % ZnSO4 + 1 % urea at tillering and panicle initiation stage (T2 + T3 + T10). The treatments T5, T6, T7 and T9 were skipped in rabi season to know the residual effect of these treatments in the subsequent season. Among the treatment combinations, application of 25 kg ZnSO4 ha-1 + FYM 12.5 t ha-1 recorded higher grain yield in both kharif (6232 kg ha-1) and rabi (6236 kg ha-1) seasons. The same treatment combination recorded higher Zn content and Zn uptake as well. Regarding soil nutrient content, the same treatment recorded higher N, P and K content. This treatment was followed by application of 25 kg ZnSO4 ha-1 + green leaf manure 6.5 t ha-1. The experimental findings suggested that combination of organic and inorganic sources not only increased the yield but also improves soil health in Cauvery delta zone.

scholarly journals The Fecal Bacterial Microbiota in Horses with Equine Recurrent Uveitis

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 745
Author(s):  
Michelle Martin de Bustamante ◽  
Diego Gomez ◽  
Jennifer MacNicol ◽  
Ralph Hamor ◽  
Caryn Plummer
Keyword(s):  
Beta Diversity ◽  
High Throughput Sequencing ◽  
Illumina Miseq ◽  
Diversity Indices ◽  
Rrna Gene ◽  
Linear Discriminant ◽  
Alpha And Beta Diversity ◽  
Bacterial Microbiota ◽  
Healthy Control ◽  
Equine Recurrent Uveitis

The objective of this study was to describe and compare the fecal bacterial microbiota of horses with equine recurrent uveitis (ERU) and healthy horses using next-generation sequencing techniques. Fecal samples were collected from 15 client-owned horses previously diagnosed with ERU on complete ophthalmic examination. For each fecal sample obtained from a horse with ERU, a sample was collected from an environmentally matched healthy control with no evidence of ocular disease. The Illumina MiSeq sequencer was used for high-throughput sequencing of the V4 region of the 16S rRNA gene. The relative abundance of predominant taxa, and alpha and beta diversity indices were calculated and compared between groups. The phyla Firmicutes, Bacteroidetes, Verrucomicrobia, and Proteobacteria predominated in both ERU and control horses, accounting for greater than 60% of sequences. Based on linear discriminant analysis effect size (LEfSe), no taxa were found to be enriched in either group. No significant differences were observed in alpha and beta diversity indices between groups (p > 0.05 for all tests). Equine recurrent uveitis is not associated with alteration of the gastrointestinal bacterial microbiota when compared with healthy controls.

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