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Sugi Panneerselvam, Nina Diklich, Jonathan Tijerina, Michelle M Falcone, Kara M Cavuoto Department of Ophthalmology, Bascom Palmer Eye Institute/University of Miami Miller School of Medicine, Miami, FL, USACorrespondence: Kara M Cavuoto, Department of Ophthalmology, Bascom Palmer Eye Institute/University of Miami Miller School of Medicine, 900 NW 17th Street, Miami, FL, 33136, USA, Tel +1-305-326-6324, Fax +1-305-547-3675, Email kcavuoto@med.miami.eduPurpose: To explore public interest in myopia progression and management and to correlate these trends to available treatments.Methods: Keywords were chosen for interest in myopia overall and those signifying interest in myopia treatments. Treatment options were separated into four main categories: atropine, glasses, contact lenses, and orthokeratology. Search terms were queried across ten years of Google Trends data and the relative search volume was analyzed to quantify the change in search volume over time.Results: A positive linear trend over time was present for all myopia interest keywords except “nearsighted” (p = 0.074) and “near work myopia” (p = 0.086). Interest in the four myopia treatment categories included in this study also displayed a significant positive trend over time. There is also a statistically significant positive correlation between all four treatment options and four of the seven categories of population interest, “myopia control”, “myopia”, “myopia progression”, and “screen time myopia”.Conclusion: This study demonstrates the utility of GT to correlate public interest in myopia treatments over time. All treatment terms had statistically significant linear search volume growth over a ten-year period. The positive correlation between interest in myopia as a health problem and available treatments supports existing evidence that GT can track rising public health concerns and corresponding treatment-seeking behaviors.Keywords: myopia, Google Trends, nearsighted, orthokeratology, atropine

Randhir Chavan,1,* Swati Panneerselvam,1,* Parul Adhana,1 Nirodhini Narendran,1 Yit Yang1,2 1Eye Infirmary, New Cross Hospital, Royal Wolverhampton Hospitals NHS Trust Wolverhampton, West Midlands, UK; 2Faculty of Life and Health Sciences, Aston University, Birmingham, UK *These authors contributed equally to this paper Background: The aim of this study was to describe bilateral visual outcomes and the effect of incomplete follow-up after 3 years of ranibizumab therapy for neovascular age-related macular degeneration. Secondarily, the demands on service provision over a 3-year period were described. Methods: Data on visual acuity, hospital visits, and injections were collected over 36 months on consecutive patients commencing treatment over a 9-month period. Visual outcome was determined for 1) all patients, using last observation carried forward for missed visits due to early discontinuation and 2) only those patients completing full 36-month follow-up. Results: Over 3 years, 120 patients cumulatively attended hospital for 1,823 noninjection visits and 1,365 injection visits. A visual acuity loss of

This study suggests an asymmetric multilevel inverter based on DSTATCOM that employs SVPWM techniques to produce higher output levels. There are two steps in the suggested inverter. One full bridge and two half bridges make up the inverter's main stage. A full bridge converter had four switches and a single DC source, while half bridges have separate DC sources with a voltage ratio of 1:3:3. Every cell has a fixed neutral point and is connected in a cascaded fashion. The inverter's performance is not improved by setting the DC source values equally. A folded cascaded H-bridge circuit running at a line frequency makes up the second circuit. Control plan PWM's space vector modulation was used to verify the suggested topology. Each control scheme's specific methodology as well as switching pulses are covered in great detail. In MATLAB/Simulink, the suggested system has been simulated with an output voltage of 350 V and an output current of roughly 3.5 A.

Land use land cover (LULC) change detection is essential for sustainable development, planning and management. This study was an attempt to evaluate the LULC change in the lower bhavani basin from 2014 to 2019, using Landsat 8 data integrating Google Earth Engine (GEE) as a web-based platform and Geographic Information System. The CART and Random Forest classifiers in GEE were used for performing supervised classification. The classified map accuracy was assessed using high resolution imagery and evaluated using a confusion matrix implemented in GEE. Five major LULC classes, viz., agriculture, built up, current fallow, forest and waterbody, were identified, and the dominant land use in the study area was agriculture and current fallow, followed by dominant land use of forest. During the study period (2014-2019) the change in built-up area 7.37% in 2019 and 5.45% in 2014, was noted due to urban sprawl. GEE showed significant versatility and proved to be an effective platform for LULC detection. [ABSTRACT FROM AUTHOR]

Sesuvium portulacastrum, a coastal medicinal plant with traditional uses has shown promising biological activities including anti-inflammatory, antioxidant and antimicrobial properties. However, the mechanisms of action active ingredients of this plant have not been studied. Aim of the current study is to investigate the anticancer activity of Sesuvium portulacastrum using in vitro and in silico analysis. The in vitro assays included NO radical scavenging activity, total phenolic and flavonoid content determination. The data were analysed by one-way-ANOVA and p

Climate change is no longer a distinct prognosis but become a reality and also proved to have its impacts on crop production. Blackgram, a C3 short duration pulse crop was considered in this study to identify the adaptability with respect to changing climate. Dynamically downscaled data (CCSM4 data using REGCM4.4 model) for 1971 to 2099 (RCP 4.5 scenario) was used for the study. The popular Blackgram cultivars CO6 and VBN6 were considered for the study after calibration and validation using DSSAT model. The impact assessment was carried out with August 1st as sowing date. The yield of Blackgram was found to have beneficial stimulus towards the changing climate under enriched CO2. Considering cultivars, difference was noticed spatially and temporally. The average yield of VBN6 was less than CO6 during base and near century, but it got reverse with time. [ABSTRACT FROM AUTHOR]

Scrub typhus is one of the important vector borne illness which is largely underdiagnosed, particularly in children. It causes mild febrile illness to severe complications. More than 20 genotypic clusters are documented from various geographical regions based on sequence variations of 56kDa type specific antigen gene of Orientia tsutsugamushi, the causative agent of scrub typhus. Adequate knowledge about epidemiology and genetic diversity in endemic regions is an important tool for clinical management, development of diagnostic kit and vaccines. Limited studies are available based on genotypic characterization of Orientia tsutsugamushi in children. The present study determined the prevalence and genotypic characterization of Orientia tsutsugamushi in febrile pediatric patients admitted in tertiary care hospital of Chennai, South India. Both serum and blood samples were collected from 239 scrub typhus suspected febrile pediatric patient’s aged between 6 months to 12 years. IgM ELISA and 56kDa nested PCR were performed on all the patient samples. Nested PCR positive samples were sequenced and analyzed for genotypic differences. Among 239 samples, 103 were positive for IgM ELISA and 35 were positive for nPCR analysis. Out of the 108 scrub typhus positive cases, 45.31% (58/128) were male and 45.05% (50/111) were female. Eschar was positive in 56.48% of patients. Pneumonia (4/108), hypotensive shock (3/108), and myocarditis (1/108) were the most common clinical complications associated with scrub typhus positive children. Karp (56.6%) was the most common genotypic cluster found in our study, followed by TA716 (33.33%), TA763 (2/30), and Gilliam (1/30).

Estimating evapotranspiration's spatiotemporal variance is critical for regional water resource management and allocation, including irrigation scheduling, drought monitoring, and forecasting. The Surface Energy Balance Algorithm for Land (SEBAL) method can be used to estimate spatio-temporal variations in evapotranspiration (ET) using remote sensing-based variables like Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), surface albedo, transmittance, and surface emissivity. The main aim of the study was to evaluate the actual evapotranspiration for the lower Bhavani basin, Tamil Nadu based on remote sensing methods using Landsat 8 data for the years 2018 to 2020. The actual evapotranspiration was estimated using SEBAL model and its spatial variation was compared over different land covers. The estimated values of daily actual evapotranspiration in the lower Bhavani basin ranged from 0 to 4.72 mm day-1. Thus it is evident that SEBAL model can be used to predict ET with limited ground base hydrological data. The spatially estimated ET values will help in managing the crop water requirement at each stage of crop and irrigation scheduling, which will ensure the efficient use of available water resources. [ABSTRACT FROM AUTHOR]

Background: Majority of the sheep farmers in our country (semi arid region) do not supplement with concentrate feed even in critical physiological stages. It was observed that concentrate supplementation in addition to free grazing substantially improved production performance of ewes and lambs. Methods: In this study the parameters such as conception rate, birth weight of lambs, fortnightly body weight changes, rumen fermentation pattern and blood parameters were recorded. Result: Out of twenty sheep in each group 16, 18 and 19 were exhibited oestrous symptoms and the percentage of heat observed were 80, 90 and 95 in the G1, G2 and G3, respectively. The numbers of animals conceived were 12, 14 and 17 and the conception percentage was 75, 77 and 89. The concentrate supplemented group showed higher conception rate. The numbers of lambs born were 12, 14 and 17 and the lambing percentages were 75, 78 and 89 for the G1, G2 and G3, respectively. The rumen pH was found to be decreasing in G3 group followed by G2 group when compared to G1 group whereas, the production of VFA was found to be higher in G3 group followed by G2 group when compared to G1 group. There were increased levels of total nitrogen, TCA nitrogen and NP nitrogen in sheep at 4 hours after feeding of concentrate feed in G3 group followed by G2 group when compared to G1 group. The results indicated that the higher levels of blood glucose, triglycerides, cholesterol and BUN were observed in G3 group followed by G2 group when compared to G1 group. [ABSTRACT FROM AUTHOR]

Dry chilli, which stands third in production from the spice industry, has influenced the Indian diet to a greater extent. The impact of climate change conditions on chilli crop could, in turn, impart the economy deeply. Hence, the future projection of dry chilli production will surely enrich knowledge about crop performance. Climate data from CCSM4 being downscaled from RegCM 4.4 was used in yield projection till the end of 21st century through DSSAT crop simulation for two major cultivars of chilli in Tamilnadu viz., TNAU chilli hybrid CO1 and K1 variety under rainfed conditions. TNAU chilli hybrid CO1 and K1 varieties have shown negative yield deviations for all the agroclimatic zones of Tamilnadu under variable time scales. However, southern zone was exclusive in exhibting positive yield by 7 percent and 5 percent, respectively, during the end of century. [ABSTRACT FROM AUTHOR]

Assessing the pulse of an important legume crop, red gram (Cajanus cajan L.) of Tamil Nadu under changing climate and framing adaptation strategies were formulated using the DSSAT model. The assessment was done for the popular variety of red gram, viz., CO(RG)7 with August 1st as sowing date, under constant CO2 (380ppm) and CO2 enrichment. The adaptation strategies such as altering the sowing date and 25 per cent increment in nitrogenous fertilizer were carried out with CO2 enrichment conditions. The yield was found to be adversely affected by the warming scenario of the climate system without CO2 fertilization. With the incorporation of enriched CO2 data, the average yield increases until the end of the century, but with temporal and spatial variations. Among the different agro climatic zones of Tamil Nadu, highest yield was recorded in Western Zone and lowest in Southern Zone. There was no response to application of Nitrogenous fertilizer. July 15 sowing was identified to be the best sowing for the base as well as future period for CO(RG)7.

Microbes play a key role in ice nucleation that facilitates bioprecipitation, which enables the plants to survive under limited water conditions. In order to test the hypothesis, a laboratory experiment was conducted to confirm ice nucleation using two phyllosphere microorganisms viz., Pseudomonas fluorescens and pink-pigmented facultative methylotrophs (PPFM). The bioprecipitation impacts on tomatoes were assessed using a set of physiological parameters such as relative water content, stomatal conductance, leaf temperature besides colony forming unit/cm2 and tube nucleation test. A field experiment was carried out in tomato (PKM 1) involving spraying of these inoculants in 3 moisture regimes (0.6, 0.8, 1.0 IW/CPE ratio) replicated four times in a factorial RBD. The data revealed that both the microbial sprays did not significantly alter the physiological parameters of tomato with an exception of leaf temperature of P. fluorescens sprayed plants with the scheduling of irrigation at 1 IW / CPE which was significantly lower (19.7°C) than PPFM sprayed ones. On the other hand, the higher relative water content of 77.4% was registered in PPFM sprayed plants irrigated at 1.0 IW/CPE ratio. In both microbial sprays, the RWC increased progressively with the advancement of the experiment from day 1 to 10 DAS and declined thereafter. However, the average stomatal conductance of the PPFM sprayed tomato plants (0.43 mmol/m2/sec) at 15 DAS was significantly higher than P. fluorescens sprayed plant (0.34 mmol/m2/sec) under all levels of moisture regimes. The PCR amplification confirms the presence of inaW genes (ice nucleation active W gene) in P. fluorescens while it was absent in PPFM. The tube nucleation tests were proved the ice crystallization induced by the P. fluorescens. Overall, the study suggests that P. fluorescens may assist in ice nucleation activity that enables tomato plants to maintain lower leaf temperature while RWC and stomatal conductance were comparable with PPFM. [ABSTRACT FROM AUTHOR]

Foxtail millet is a short duration crop grown in the arid and semi-arid regions of the world. The increasing global temperature may lead to a shift in cropping pattern across the world. Hence it is essential to understand the effect of elevated temperature on foxtail millet, as it is predominantly grown crop in the underdeveloped countries of the world. A study was conducted to investigate the effect of elevated temperature on the growth parameters of foxtail millet in Open Top Chamber at Tamil Nadu Agricultural University during 2017-2018. The experiment included exposing four different phenological stages of foxtail millet to three temperature levels. The Study revealed that the growth parameters such as plant height, leaf area and dry matter production decreased with increase in temperature. Thus the temperature rise had a negative impact on the growth parameters of foxtail millet. [ABSTRACT FROM AUTHOR]

Sugarcane is an important cash crop, contributing to 4.6 per cent of total agricultural output. In a few regions, though sugarcane had widespread area, the productivity is very less. In a few other regions, the productivity is very high but acreage under sugarcane is low. This warrants delineation of effective cropping zones for sugarcane. District wise statistics on area, production and productivity of sugarcane for southern Indian states was collected to compute Relative Spread Index (RSI) and Relative Yield Index (RYI) to classify the zones into Most Efficient Cropping Zone (MECZ), Area-Efficient Cropping Zone (AECZ), Yield Efficient Cropping Zone (YECZ) and Inefficient Cropping Zone (IECZ). Analysis indicated that the maximum efficient cane growing zone is in Tamil Nadu, followed by Karnataka, Andhra Pradesh and Telangana. Sugarcane is not preferred in Kerala due to the prevailing climatic conditions. This analysis helps in the identification of options for improving the sugarcane area and production. [ABSTRACT FROM AUTHOR]

Astrometeorology is a great science and gift from our ancestors known to humankind. Compared to statistical and numerical methods of forecasting, astrometeorology method has no time restrictions and weather could be forecasted for the next hour to a date far in the future. Wind speed is the weather parameter plays an important role in crop production. A study on the relationship between the wind speed events and the planet's azimuth was conducted at Tamil Nadu Agricultural University during 2017-18 as a part of the formulation of astrometeorological rules for wind speed events. Hourly wind speed observed between 2011 and 2016 from each one location from 31 districts of Tamil Nadu were correlated with the ephemeris developed for the same period in Alcyone ephemeris calculator. It could be concluded from the correlation study on individual planet azimuth and wind speed events that the azimuth range of 61 - 120 of all the planets and 240 - 300 had a good influence on wind speed. The 61 - 90 degrees azimuth of the Sun, Mercury, Saturn and Neptune had good influence on calm to light air wind speed events (0 - 12 km). The 91 - 120 degrees azimuth of all the planets had influenced moderately to heavy wind (19 - 45 km/hour). The Moon, Mars, Jupiter, and Neptune at 60 - 90 degrees azimuth had influenced the extreme wind speed events. The Moon, Mars and Saturn at 271 - 300 degrees azimuth had influenced the moderate to heavy wind (19 - 45 km/hour). [ABSTRACT FROM AUTHOR]

Weather Research and Forecasting (WRF) model is a numerical weather prediction system and having wide range of applications. It offers multiple physics options that could be combined in any way to improve the accuracy of forecast suitable to particular region. Each physics option has it's own individuality and no single scheme could perform better in all locations. In this context, a study was carried out to identify the best WRF microphysics scheme for improvingmedium range rainfallforecastissued by Tami Nadu Agricultural University at block levelforTamil Nadu. Based on the review of previous studies, the present study was restricted to three microphysics options which are suitable for tropical conditions viz. Kessler scheme, WSM3 and WSM6 class schemes. Forecast wasdeveloped daily at 3 km resolution with a lead time of six days for 32 locations of Tamil Nadu and for the first fortnight of November 2017. The simulated forecast values were verified with the observed data collected from the Automatic Weather Stations of TamilNadu Agricultural Weather Network (TAWN) using skill score and root mean square error verification methods. Input data resolution and microphysics option had huge impact on model performance. Data resolution of 0.25 degree performed better than 0.50 degree in all microphysics schemes considered for the study. Among the three microphysics options, the Kessler scheme had higher rainfall forecast accuracy than WSM 3 class scheme and WSM 6 class scheme. Root mean square error was also low in Kessler scheme compared to other two schemes. Kessler scheme produced highly usable forecast than WSM 3 and 6 class schemes. Hence, it is concluded that the Kessler scheme with 0.25o input data resolution produced higher rainfall forecast accuracy for Tamil Nadu region. [ABSTRACT FROM AUTHOR]

Climate change induced extreme weather events such as drought and flood condition are likely to become more common and associated impacts on crop production will be more without proper irrigation planning. The present investigation was undertaken for assessing the impact of Climate change on tomato yield and water use efficiency (WUE) using AquaCrop model and RegCM 4.4 simulations. The water driven AquaCrop model was validated based on observation of field experiment conducted with four different dates of sowing (1st November, 15th November, 1st December, 15th December) at Ponnaniyar basin, Tiruchirappalli. Validation of AquaCrop model indicated the capability of AquaCrop in predicting tomato yield, biomass and WUE close to the observed data. Seasonal maximum and minimum temperatures over Tiruchirappalli are projected to increase in the mid-century under both RCP4.5 and RCP8.5 scenarios. Maximum temperature is expected to increase up to 1.7 °C/2.5 °C in SWM and 1.9 °C/2.9 °C in NEM by the mid of century as projected through stabilization (RCP 4.5) and overshoot emission (RCP 8.5) pathways. Minimum temperature is expected to increase up to 1.6 °C/2.2 °C in SWM and 1.6 °C/2.1 °C in NEM by the mid of century as projected through stabilization (RCP 4.5) and overshoot emission (RCP 8.5) pathways. Seasonal rainfall over Tiruchirappalli is expected to decrease with RCP4.5 and RCP8.5scenarios with different magnitude. Rainfall is expected to change to the tune of −1/−11 per cent in SWM and −2/−14 per cent in NEM by the mid of century as projected through stabilization (RCP 4.5) and overshoot emission (RCP 8.5) pathways. [ABSTRACT FROM AUTHOR]

Among the pulses, bengal gram (Chickpea) has been considered for the present study in the scenario of uncertain monsoon behaviour where it is an excellent crop benefiting the farmers since its ability to withstand drought condition with lesser rainfall. The present study was under taken intentionally to assess the trends in area, production, productivity and Efficient cropping zones (ECZ) of the emerging pulse crop (Bengal gram) of Tamil Nadu, to identify and analyse the factors influencing the area, production and productivity of bengal gram as well as to key note the available niches over the state (Tamil Nadu). The zones were identified for latest 10 year average (2005-2014). The trend analysis was carried out for 1950-2014, 1950-1979 and 1980-2009 and at decadal scale for state level. The results showed that the trend in area, production and productivity were increasing with the new technologies that could further extend the crop over the efficient cropping zones. The compound growth rate of 2.44 per cent per annum over Tamil Nadu during the time period of 1950-2014 could be achieved as a whole. Coimbatore, Tiruppur, Dindigul and Dharmapuri districts of Tamil Nadu during the latest ten years, 2005 to 2014 were found to be the efficient cropping zones for bengal gram from this study. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore during late Samba season (2017-18) to study the effect of varieties and methods of planting on productivity of organic rice. The experiment was laid out in split plot design with three replications. Four varieties (V1 - Rice CO-52, V2 - Jeeraga samba, V3 - Kitchili samba and V4 - Improved white ponni) were grown in main plot and three planting methods (P1 - Random planting, P2 - Line planting and P3 - SRI method) were allotted to sub-plots. The experimental results revealed that Rice CO-52 registered lesser plant height (113.2 cm), higher drymatter (10330 kg ha-1), LAI (4.70), total number of tillers (441/m²), number of productive tillers (394/m²), total number of grains and filled grains, grain yield (3780 kg ha-1) and harvesting index. Among methods of planting, SRI method of planting registered higher growth characters, yield attributes and yield of rice than other methods of planting. Hence, it is inferred that SRI method enhanced productivity of rice under organic farming. [ABSTRACT FROM AUTHOR]

New EC formulations (10, 20, 30 and 40 EC) were developed using combination of lemongrass oil, cinnamon oil and thyme oil for the management of post harvest anthracnose of pomegranate caused by Colletotrichum gloeosporioides and tested at 0.1% concentration in vitro. Among them, essential oils based new 30 EC formulation, completely (100%) inhibited the pathogen growth at 0.1% concentration. The formulation was named as THYCILEM 30 EC and tested for its physical stability. The formulation was stable in all physical stability tests and was not inhibitory to antagonistic micro organisms. The in vivo results revealed that pre harvest spraying with new THYCILEM 30 EC (0.1%) followed by post harvest dipping with new THYCILEM 30 EC (0.1%) for 5 min was more effective in reducing pomegranate anthracnose which had the minimum PDI of 13.43 after 24 days of treatment under post harvest conditions, compared to 87.50 PDI in untreated control. The application of new THYCILEM 30 EC as pre harvest spray and post harvest dipping did not show any drying, scorching of leaves and browning of fruits which was noticed by visual observation. [ABSTRACT FROM AUTHOR]

Temperature is one of the most important environmental factors that influence the crop growth, its development, and yield. With the increase in the accumulation of GHGs in the atmosphere, there is a rise in surface temperature as compared to pre- industrial period. An experiment was conducted during rabi season of 2013- '14 to study the impact of elevated temperature with and without CO2 fertilization on rice (C3) and maize (C4) crops, using Temperature Control Chamber and Soil plant Atmospheric Research system at the Agro Climate Research Centre of Tamil Nadu Agricultural University, Coimbatore. Temperature elevation of 4 °C from the ambient level in the TCC and temperature elevation of 4 °C with 550 ppm CO2 in the SPAR chamber were considered for experimentation. Increase in temperature with or without CO2 enrichment affected the phenology and productivity of C3 and C4 plants under different magnitude. Rice and maize crops grown under 4 °C elevated temperature attained panicle initiation, flowering and maturity earlier than the crop grown under ambient condition. The treatment 4 °C elevated temperature also recorded reduced number of tillers in rice, number of leaves in maize and dry matter production in rice and maize. This treatment did record lower rice grain and straw yields . Maize grain and stover yields also got reduced. As far as the physiological response of C3 (rice) and C4 (maize) was considered, the photosynthetic rate was significantly low when the plants were kept under warmer environment than under ambient condition and the rate of decrease was higher in rice compared to maize. However, the CO2 enrichment compensated this reduced photosynthetic rate. The interaction effect between temperature and CO2 in rice indicated that CO2 enrichment had minimized the yield loss by 10 per cent as compared to three per cent obtained under maize crop. The transpiration rate and stomatal conductance were significantly increased in both rice and maize crops under elevated temperature compared to ambient condition and the rate of increase was higher in rice than in maize, yet, CO2 enrichment compensated these ill effects of elevated temperature to certain extent in maize, and to a considerable extent in rice. [ABSTRACT FROM AUTHOR]

An investigation to assess the greenhouse gases (GHG's) fluxes in rice cultivation under current and elevated temperature was carried out at Agro Climate Research Centre, Tamil Nadu Agricultural University, Coimbatore, during rabi season (November 2014 - March 2015). This experimentation was carried out with two temperature levels viz., current temperature at open environment and +2°C elevated temperature at Temperature Controlled Chamber. During the experimentation, GHG emission rate was evaluated. The nitrous oxide emission attained maximum at 15 DAT followed by 45 DAT and then decreased towards maturity. The methane emission rates increased with age of the crop, but attained maximum at harvesting stage. The methane emission rates from rice crop grown under open environment were higher than elevated temperature. The nitrous oxide emission rates from rice crop grown under +2°C elevated were higher than open environment. Methane is normally translocated through rice plants and the higher biomass generation under open environment led to higher methane translocation. The nitrous oxide emission was normally through microbial activity and the higher microbial activity was in elevated temperature led to more nitrous oxide emission. The tradeoff between CH4 and N2O emission has to be analyzed critically and developing appropriate nutrient and water management strategies and maintaining the soil redox potential at an intermediate range (-100 to +200 mV) would minimize emissions of both CH4 and N2O. Overall, the data have shown clear evidence that rice cultivation in future reduced methane emission but increase nitrous oxide emission. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore in the rabi season in order to assess the sustainability of SRI in changing climate. Three aspects of rice cultivation, GHG emission, water use, and Energy consumption were accounted to vindicate the sustainability of SRI over other cultivation systems. Three rice cultivation systems SRI (System of Rice Intensification), AWD(Alternate Wetting and Drying) and conventional were selected which differ in agronomic and water management practices. CH4, N2O and CO2 gas emissions from field were collected using static closed chamber and was analyzed using a gas chromatograph equipped with FID. Water irrigated to the field was measured in m3 using a water meter. The results showed that SRI method of cultivation recorded less GHG emissions and water use with higher yield. Alternate wetting and drying method of water management reduced methane emission in AWD by 41 per cent and SRI by 44.3 per cent when compared with conventional system. [ABSTRACT FROM AUTHOR]

The lowland rice cultivation is recognized as one of the major methane sources. The application of amendments that contain high amount of electron acceptors would inhibit the methanogenic activity and hence methane emission. Fly ash is a by-product containing ferro- alumino- silicate minerals whereas gypsum is sulphate of calcium. A field experiment was conducted to estimate the effect of fertilizers like Urea and Neem treated Urea and soil amendments like fly ash and gypsum along with recommended dose of fertilizers on the methane emission from the rice field. Gas samples were collected from the field using Static open-bottom perplex chamber technique and estimated in a Shimadzu GC-2014 gas chromatograph equipped with FID. The rate of methane emission was found to be lesser at the active tillering stage which attained a peak at the panicle initiation stage and then got declined till maturity stage. This trend was noticed irrespective of the treatments evaluated. The substitution of neem treated urea instead of urea had no significant impact on the methane emission whereas the application of either gypsum or fly ash or in combination along with RDF significantly decelerated the methane emission. [ABSTRACT FROM AUTHOR]

Weeds are one of the important biotic factor, compete the crop for its resources and difficult to eliminate completely from agricultural system. Weeds respond very quickly to stress and adopt easily than crops to climatic stress. In this context, a pot culture experiment in climate control chamber with three temperature levels (0°C, +2°C and +4°C increase over the ambient) and two moisture levels (supply of moisture at 100 %, and 60 % ET of previous day) was carried out at Agro Climate Research Centre, Tamil Nadu Agricultural University, Coimbatore during 2015 -16 to understand weeds response to future climate scenarios. The results inferred that, the problematic weed Cynodon dactylon had high acclimatization capacity and produced more growth under elevated temperature up to +4°C with sufficient moisture. The C4 pathway of bermuda grass helps that weed to utilise the moisture and temperature more efficiently even during stress and produce more growth. Moisture stress with increased temperature had negative effect on growth, but induced the early flowering and more seed production in Cynodon dactylon. It is concluded that, in near future with elevated temperature, the crop production in both dry and wet seasons would suffer from severe Cynodon dactylon menace. Hence, necessary precaution measures against Cynodon dactylon have to be included in climate change adaptation technologies. [ABSTRACT FROM AUTHOR]

In India, agriculture sector provides the largest livelihood support and contributes by 17.3 percent to the Gross Domestic Product (GDP). Maize is the third most important food crop after rice and wheat, occupying about 7.5 million hectares of land area in India. In Tamil Nadu maize is cultivated mainly as rainfed crop during Rabi season. Requirement of maize is growing fast and given the importance, a study was carried out at Agro Climate Research Centre, Tamil Nadu Agricultural University, Coimbatore during 2015-2016 to assess the impact of climate change on rainfed maize productivity over Tamil Nadu during mid-century (2040 to 2069) period. The Representative concentration pathway 4.5 and 8.5 was selected to represent the stabilization and over shoot pathways of emission. Maximum temperature was expected to increase to a maximum up to 4.7°C while minimum temperature to 5.7°C. Rainfall is anticipated to vary from a decrease of -33.0 percent to and increase of +45.1 percent.The future climate projected by these models was integrated with DSSAT to simulate the impact on rainfed maize productivity over Tamil Nadu. Under changing climate, rainfed maize productivity is expected to decline to a maximum of 30 percent from the current yield levels. [ABSTRACT FROM AUTHOR]

A study was conducted at Agro Climate Research Centre, Tamil Nadu Agricultural University, Coimbatore, during 2015-16 to improve the accuracy of numerical model rainfall forecast using astrometeorological principles. Daily rainfall forecast were developed for each one location from seven agro climatic zones of Tamil Nadu, through different source and methods viz., WRF (numerical model), astrometeorology (planet), probability, a private agency forecast and hybrid forecast (superimposing astro and probability forecast on WRF) and were compared using forecast accuracy ratio and critical success index. In general, irrespective locations and seasons, the hybrid forecast had higher forecast accuracy (0.75 to 0.88) and critical success index (0.56 to 0.76). Among the different individual forecasts, the astrometeorological forecast had highest forecast accuracy (0.74 to 0.87) and critical success index (0.52 to 0.71). The study concluded that, astrometeorology could be a good option for alternate forecasting method to numerical weather forecast and hybrid forecast developed by integrating astrometeorology, numerical and probability methods will improve the rainfall forecast accuracy and critical success index, in turn will increase the usability of forecast in agriculture. [ABSTRACT FROM AUTHOR]

Rainfall is a nature's gift carrying certain essential plant nutrients from atmospheric reactions. Rainfall contribute considerable amount of Nitrogen as equal parts of nitrate (NO3) and ammonical (NH3) forms and sulfur (SO4) for plant use. These nutrients in the rainfall had good impact in agricultural production during those days, when environmental conditions was better with less toxic substances in atmosphere. The throughfall, precipitation that drips from the foliage and runs down the boles of trees are substantially enriched with leached bio elements and which are mostly essential plant nutrients. Study during North East Monsoon 2015 (NEM) and Summer 2016 (SUM) inferred that, both the rainfall and through fall are potential source of plant nutrients and the amount of nutrients delivery varies with type of vegetation. It is quite interesting to note that the amount of nitrogen (both nitrate and ammoniacal form) delivered by rainfall and throughfall were worked out to nearly 33 and 68 kg/ha which is sufficient for the most of rainfed crops. Among the agro forestry tree species, throughfall from Azadirachta indica had higher N, K and Mg, throughfall from Casuarina equisetifolia had Ca which resulted in higher pH and EC, throughfall from Peltophorump terocarpum had P2O5 and Na and throughfall from Cassia fistula had more SO4.The study periods imputes collection, conservation and recycling of rainfall to sustain the productivity of crop, particularly rainfed agriculture. [ABSTRACT FROM AUTHOR]

The article focuses on the study on the impact of El Niño-Southern Oscillation (ENSO) induce rainfall on the productivity of maize farm in Tamil Nado, India. Topics discussed include the measurement of ENSO condition using the Southern Oscillation Index (SOI), the influence of SOI phases on the characteristics of rainfall during the rainfed cropping period, and the statistical analysis of the effect of SOI phase son maize growth and yield.

Drought is one of the recurrent climate phenomenon that crippling the societal and economic development of the agrarian country. It occurs almost everywhere, although its features vary from region to region. The present study was undertaken to assess the drought in Tamil Nadu using the precipitation data of historic climatic period (1981-2017) with high spatial resolution (17 Km). Rainfall deviation from the long term mean during SWM, NEM and annual time scale was calculated at district level for identifying the drought prone districts in Tamil Nadu. The results showed that the frequency of the drought events was higher during the SWM as compared to NEM. Results indicated that Tirunelveli, Theni, Tiruppur, Karur, Tiruchirapalli districts were prone to the drought during SWM. As the NEM is the primary rainfall season and active crop growing period, suitable drought mitigation strategies need to be designed for the districts viz., Kanyakumari, Salem, Thiruvallur, which are highly affected due to deficit rainfall during NEM. [ABSTRACT FROM AUTHOR]

Several factors are responsible for recent climatic anomalies includes seasonal and inter-annual variability of rainfall in the region in which regional and global sea surface temperature (SST) changes is the most significant factor. It is well recognized that El Niño Southern Oscillation (ENSO) is the dominant mode of climate variability on seasonal to inter-annual scales and its impacts are felt worldwide. Seasonal to inter-annual rainfall fluctuations strongly affect the success of agriculture and the abundance of water resources. Daily rainfall data at district scale was obtained from India Meteorological Department (IMD) for a period of 43 years (1971–2013) was categorized based on the ENSO episodes and the analysis was performed for the rainfed cropping period (RCP, September–December). A week (7 days) with the cumulative rainfall amount of 50 mm was considered as one wet spell. Non rainy days observed continuously for a decade (10 days) that period was considered to be one dry spell. Results revealed that El Niño conditions positively influenced the rainfall. Compared to neutral years, La Niña years received less rainfall as it showed the negative deviation in most of districts of Tamil Nadu. More wet spell and lesser dry spell weeks was observed under El Niño condition while the lesser wet spell and more dry spell was observed under La Niña conditions. Higher amount of rainfall during El Niño led to more number of wet spells under El Niño event. [ABSTRACT FROM AUTHOR]