Impact of root architecture and transpiration rate on drought tolerance in stay-green sorghum

Sorghum [Sorghum bicolor (L.) Moench] yield loss due to terminal drought stress is common in semiarid regions. Stay-green is a drought adaptation trait, and a deeper understanding of stay-green-associated traits is necessary for sorghum breeding. We hypothesize that the stay-green trait in sorghum may be associated with the root architecture and transpiration rate under drought stress. The objectives were to (i) identify the relationship among stay-green-associated traits, (ii) compare the root system architecture and transpiration rate of stay-green (B35 and 296B) and senescent (BTx623 and R16) genotypes under drought stress, and (iii) quantify the impacts of reproductive stage drought stress on gas exchange and grain yield of stay-green and senescent genotypes. A series of drought experiments were conducted with these genotypes. Under drought stress, the stay-green genotypes had an increased total root length in the top 30–60 cm (18%) and 60–90 cm of soil (45%) than the senescent genotypes. In contrast, under progressive soil drying, stay-green genotypes had a decreased transpiration rate (9%) than senescent genotypes by an early (∼1 h) partial closure of stomata under high vapor pressure deficit conditions. The increased seed yield (43%) in stay-green genotypes is due to an increased photosynthetic rate (30%) and individual seed size (35%) than senescent genotypes. Overall, it is concluded that stay-green phenotypes had two distinct drought adaptive mechanisms: (i) increased root length for increased soil exploration for water and (ii) an early decrease in the transpiration rate to conserve soil moisture. Identifying genomic markers for these traits would accelerate drought-tolerant sorghum breeding

A Study on Astrometeorological Relationship between Planet Azimuth and Temperature

Temperature is one of the key weather parameters, which is a necessity for all life on Earth. Any variation from the normal can impede the physical, chemical, and biological processes of life. Extremes would produce permanent changes that would halt the plant's growth and may cause complete withering. Advance information on temperature events will be helpful in protecting the plant and sustain the productivity under any temperature related disasters. Astrometeorology is one of the oldest organized knowledge systems that interplay between planetary movement and weather. In Tamil Nadu Agricultural University (TNAU), Astrometeorological weather forecast rules for rainfall, wind speed and cyclone events were already well defined. In continuation of this research, identification of Astrometeorological rules for the temperature events had been taken up during 2021-2022 at Agro climate Research Centre, TNAU, Coimbatore. Hourly temperature data from 2011-2016 was collected for 30 districts of Tamil Nadu. In each districts one particular location is selected and is correlated with ephemeris developed for a particular location using Alcyone ephemeris calculator. The findings clearly demonstrated the differential impact of individual planets and their azimuth on the temperature events. The study revealed that low temperature events were influenced when most planets are away (271- 300 degree azimuth) whereas the high temperature events were influenced by the planets that are directly above the location (91 to 120 degrees azimuth) and the in between temperature events were influenced by both 61-90 and 241-270 degrees. The specific azimuth of the Sun, Mercury, Venus, Jupiter, Saturn, Uranus, and Neptune had a makeable influence on a particular temperature event, however all the azimuths of the Moon and Mars had only a mild effect on any temperature event. Based on the results, Astrometeorological rules for the temperature events could be defined and used for the development of hybrid forecasting by overlapping the astromet forecast output on the numerical forecast output. This will produce more accuracy than individual forecast, reduce missing forecast, falls alarms, and improve the usability of forecast

Association of Different Satellite Driven Products with Evapotranspiration in Tamil Nadu, India (2010-2020)

Evapotranspiration is an important phenomenon of hydrological cycle mainly influenced by meteorological factors and other vegetation characteristics. In this study, the relationship between Actual Evapotranspiration (AET) with Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) were analysed using Moderate Resolution Imaging Spectroradiometer (MODIS) TERRA satellite data products with the help of Geographic Information System (GIS) software. The duration of study was during South West Monsoon (SWM) season from June to September, over a period of ten years (2011 to 2020) for all seven Agro Climatic Zones (ACZ) of Tamil Nadu, India. The results showed that moderate to strong positive correlation were observed between AET and NDVI (r= 0.3 to 0.9) in all seven ACZ. The AET and LST showed a weak to strong negative correlation (r= -0.4 to -0.7) in six ACZs except High Rainfall Zone (HRZ) which might be due to lower LST and high NDVI values recorded in the HRZ which exhibited a weak positive relationship (r=0.2). Relationship between AET, LST and NDVI are highly useful for parametrizing evapotranspiration in different climatic conditions, analyzing different crop growth and production and helps in planning water management strategies at regional scale

Influence of Weather Parameters and Thermal Time Approach on Green Gram at Coimbatore, Tamil Nadu

An investigation was carried out at the Agro Climate Research Centre, Tamil Nadu Agricultural University, on the effect of weather parameters on the green gram yield sown at various sowing dates during the rabi season of 2019. At various sowing dates, two green gram cultivars, VBN 4 and ADT 3, were sown. For both cultivars, the phonological crop length decreased with delays in sowing dates beyond October 23rd. The yield of green gram sown on 23rd October was significantly higher than the crops sown on 30th October and 6th November. The weather parameters Maximum Temperature (Tmax), Diurnal Range (Trange), Bright Sunshine Hours (BSS), Relative Humidity (RH I), Wind Speed (WS) were found to be negatively correlated with seed yield whereas Minimum Temperature (Tmin), Relative Humidity (RH II), Vapour Pressure (VP) were found to be positively correlated with the yield of green gram. The accurate prediction of green gram yield could be done with the maximum temperature, bright sunshine hours, wind speed and with thermal indices especially hygrothermal unit II with 82 percent, accuracy level

Biochemical analysis of female mice urine with reference to endocrine function: a key tool for estrus detection.

Species-specific chemical signals released through urine, sweat, saliva and feces are involved in communication between animals. Urinary biochemical constituents along with pheromones may contribute to variation across reproductive cycles and facilitate to estrus detection. Hence, the present study was designed to analyze such biochemical profiles, such as proteins, carbohydrates, lipids, fatty acids, in response with steroid hormones such as estradiol and progesterone. The experimental groups were normal, prepubertal, ovariectomized, and ovariectomized with estrogentreated female mice. In normal mice, the protein and lipid concentrations in urine were significantly higher in proestrus and estrus phases and the quantity of fatty acids was also comparatively higher in estrus. Furthermore, certain fatty acids, namely tridecanoic, palmitic and oleic acids, were present during proestrus and estrus phases, but were exclusively absent in ovariectomized mice. However, the carbohydrate level was equally maintained throughout the four phases of estrous cycle. For successful communication, higher concentrations of protein and specific fatty acids in estrus are directly involved. The significant increase in estradiol at estrus and progesterone at metestrus seems to be of greater importance in the expression pattern of biochemical constituents and may play a notable role in estrous cycle regulation. Thus, we conclude that the variations observed in the concentration of the biochemical constituents depend on the phase of the reproductive cycle as well as hormonal status of animals. The appearance of protein and specific fatty acids during estrus phase raises the possibility to use these as a urinary indicators for estrus detection

Spatial Vulnerability Assessment and Diurnal Climatology of Lightning Events in Tamil Nadu, India

The research probes into the seven agro climatic zones in Tamil Nadu which are highly vulnerable to lightning strikes, as well as the human fatalities caused by Cloud to Ground lightning. The purpose of the study is to find out the vulnerable hotspots and diurnal climatology of the Cloud to Ground lightning strikes during the northeast monsoon, southwest monsoon, and summer seasons. Heat maps are used for the lightning strikes using ArcGIS software and the diurnal climatology was performed by interpolating the data from the lightning location network into a 3-hour resolution. In vulnerability analysis, Northeastern zone is more prone to lightning during Southwest and Northeast Monsoon. On the other hand, High rainfall zone and Hilly zone are vulnerable to lightning in summer season. The Northeast monsoon has the highest lightning frequency ratio, followed by the summer. The maximum rate of strikes occurred between 10-15 hrs IST and showed a peak range between 10:00 to 12:00 hrs IST. A labor-intensive agricultural economy is linked to higher rates of lightning-related deaths and injuries. The results of this research could be useful in developing lightning climatology for the future climatic condition for Tamil Nadu