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Aim: The present study was taken up to assess the imidacloprid residue pattern in order to define strategies for improvement of quality and safety mainly healthfulness in grapes. Place and Duration of Study: The present study was carried out in Tamil Nadu during the period 2020-2021. Methodology: Dissipation studies were carried out in a farmer’s field at Theni, India (9o N latitude and 76o E longitude and 375m above mean sea level) with all good agricultural practices. During this study Grapes (Muscat Hamburg variety) was grown and the commercial formulation of imidacloprid 17.8% SL was applied at recommended dose (53 a.i ha-1) and double dose (106 a.i ha-1) Two sprays were given with an interval of 10 day by using a power operated sprayer as 500 L ha-1 spray fluid for dissipation study. The samples were processed by adopting modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method. Results: The initial deposit imidacloprid in grape berries was 0.65 and 1.56 mg kg-1 at the recommended dose (53 g a.i ha-1) and double dose respectively (106 g a.i ha-1). The insecticide exhibited a slower dissipation rate and reached below its quantification level (

Climate influences the spread of the any crop by imposing environmental restrictions. The present investigation was carried to understand the effect of climate on cocoa in various cocoa growing regions. In order to establish the relationship between weather parameters and cocoa productivity, Coimbatore, Theni, and Tenkasi were chosen as the study regions. Historical climate data was acquired from India Meteorological Department (IMD) for the past 30 years (1991-2020). Cocoa yield was simulated by using the Agricultural Policy/Environmental eXtender (APEX) and it was correlated with the weather variables such as rainfall, maximum temperature, minimum temperature, atmospheric water demand (PET), and crop water requirement (ET). Cocoa crop had positive correlation with rainfall and Actual Evapotranspiration. Whereas, both maximum and minimum temperature had significantly negative effect. Climatic conditions, such as decrease in rainfall, increase in temperature and increase in PET, would significantly reduce the cocoa bean yield. The anticipated increase in temperature and erratic rainfall distribution requires suitable management measures for sustainable cocoa productivity.

Climate change, as well as an increase in extreme weather, are posing a serious threat to socioeconomic and livelihood security. For this study, the Cauvery delta zone (CDZ) was chosen to examine current and anticipated climate variability and trend. The four largest districts of Tamil Nadu's Cauvery delta region are Thanjavur, Thiruvarur, Mayiladuthurai, and Nagapattinam. The Indian meteorological agency provided the baseline data sets (IMD). Using IPCC AR5 RCP4.5 and RCP8.5 scenarios, the maximum and minimum temperatures, as well as precipitation, were investigated. The maximum temperature could rise to 1.1oC to 3.6oC, while the minimum temperature could rise to 2.8 to 4.5oC, according to the findings. It was also concluded that there will be 15-16% rise in the rainfall during end of the century.

Increased concentration of greenhouse gases is expected to alter the radiative balance of atmosphere, causing increase in temperature and changes in precipitation patterns. Climate variability has been principal source of fluctuations in Indian food production. Even though there is no long-term trend, inter - annual variability of Indian monsoon rainfall leading to frequent droughts and floods has profound influence on agriculture and intern, national economy. 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. ENSO often affects seasonal temperature, precipitation and thus crop yields in many regions, however, the overall impacts of ENSO on global yields are uncertain Maximum and minimum average temperature was calculated for different seasons such as Cold Weather Period (CWP), Hot Weather Period (HWP), South West Monsoon (SWM), North East Monsoon (NEM) for each El Niño, La Niña and neutral years at various districts of Tamil Nadu. Relation between ENSO and temperature was analyzed by computing the anomaly in temperature at different districts of Tamil Nadu. The temperature deviation between the ENSO and neutral phases was not significant as the deviation was within + 0.3oC in all the seasons.

Drought happen aimlessly and there is no periodicity in its event and can't be anticipated ahead of time. In semiarid stations, the event of precipitation is occasional and is known something else for its changeability regarding reality. Meteorological drought is characterized as the time of drawn-out dry weather pattern because of underneath ordinary precipitation. Drought is an extensive stretch of incredibly low precipitation that essentially affects crop result and individuals' prosperity. Recent study has made substantial progress in understanding drought in Tamil Nadu, as well as the implications of climate change, but more research is needed because regional climatic responses remain unknown. The Meteorological Drought Indicator was also a useful and appropriate index for drought monitoring in the research area since it provided drought analysis on a variety of timeframes. This study might help us better understand the features of drought.

Rainfall is one of the most important climatic variables that determine the spatial and temporal patterns of climate variability of a region, which also provides useful information for the planning of water resources, agricultural production, and others. Climate change is one of the most significant worldwide issues talked among scientists and researchers, and one of the consequences of climate change is the alteration of rainfall patterns. 'India's population and the economy is linked to climate-sensitive activities, including rainfed agriculture and excess climate anomalies, deficient and flooded rainfall years have a dramatic impact on the economy as well as on the living conditions of the inhabitants of the affected region. An understanding of current and historical trends and variation is inevitable to her future development, especially in agricultural and hydrological sectors. In the present study, historical weather data for 33 years (1981-2013) was analyzed for rainfed cropping season (September - December) to understand the climatic variability in the Kanyakumari district of Tamil Nadu. The maximum daily air temperature increased on average by 0.02°C per year, whereas minimum daily air temperature remained constant during the rainfed cropping season. The high rainfall zone receives an annual and rainfed cropping average rainfall of 1307and 672 mm, respectively. Analysis of rainfall during rainfed cropping period over 33 years showed ten years had standard RF, nine years had deficit rainfall, six years had below standard RF, one year had above standard RF and seven years had excess RF. Analysis indicates that the deficit condition prevailed in every alternate year in recent decades. The onset of rainfed cropping season varied over the years (1981-2013), 13 years had onset in the slot from 1st to 5th September, and in others, years onset occurred between 6 and 30th September. Cessation also had a variation over 33 years and 16 years had cessation from 26 to 31st December while remaining years had cessation in the period of 1-25th December. LGP ranged from 57 to 143 days, with an average LGP of 106 days. Dry spell varied from 3 to 12 days with the mean of 6 days, and wet spell varied from 2 to 8 days with an average of 5 days.

Rainfall has a greater impact on agricultural, hydrological, economic, environmental and social systems. Inconsistencies in rainfall pattern could lead to extremities like drought and flood. Drought is a long period of unusually low rainfall that severely affects crop production and welfare of the people. Understanding the impacts of drought is crucial for planning, mitigation and responses. The Standardized precipitation index (SPI) method was employed for identifying drought occurrence in Parambikulam aliyar basin based on rainfall data of 37 years (1981–2017). SPI method indicated PAP basin had drought once in 4 years. In 19 per cent times, wet situation found to exist in PAP basin, five years exhibited moderately wet condition (1984, 1996, 2010, 2015 and 2017) and two years (1992 and 2005) fell under extremely wet event. Quantification on the drought events forms the scientific basis for decision makers to reduce the societal vulnerability to drought.

Drought tends to be a creeping phenomenon occurs gradually with the deficiency in rainfall further extending its impact on sectors which are dependent on water. The drought characteristics were analysed in Parambikulam Aliyar Project (PAP) basin based on the European Centre for Medium range Weather Forecasts Interim Reanalysis (ERA-Interim) gridded data with resolution of 0.125° ×0.125° during 1981-2017. Reconnaissance Drought Index (RDI) was applied for monitoring the drought. The variables used in RDI are rainfall and potential evapotranspiration (ETo), the required meteorological data were taken from the ERA Interim dataset and ETo was calculated using Penman-Monteith method. RDI indicated that 41% of the time had drought condition over 37 years. Two years (1982 and 2012) faced severe drought across all the parts of the PAP basin and the highest number of mild drought events were observed than the other drought conditions in PAP basin. Results showed that Plain areas in PAP basin experienced maximum number of drought events compared to the other areas in PAP basin during the investigation period.