Biopriming of seeds with microbial biostimulant (Bacillus megaterium ) on improvement of seedling growth, biochemical and root traits of rice (Oryza sativa L.)

This study aimed to evaluate the potential of Bacillus megaterium in improvingseed germination and rice seedling's morpho-physiological andbiochemical traits. The experiment was conducted using a completely randomizeddesign to evaluate the effect of different concentrations of the biostimulantB. megaterium on rice seedlings growth and development undernursery conditions. Biopriming seeds with B. megaterium significantly enhancedseed germination and seedling traits, such as seedling shoot androot length, seedling height, number of leaves, seedling vigor, and shootand root dry biomass, compared to the untreated control. Among the treatments,biopriming seeds with B. megaterium at a concentration of 10g kg-1resulted in the greatest improvements across all the recorded parameters.Root traits such as total root length, surface area, average root diameter,root volume, and root tips and forks were also significantly enhanced. Additionally,biochemical changes like total chlorophyll and soluble protein contentshowed notable improvements with the concentration of B. megaterium. Hence, these results suggest that biopriming seeds with B. megateriumare an efficient strategy to improve seed germination and shoot and rootvigor in rice seedlings

Thidiazuron as a defoliant to facilitate mechanical harvesting in cotton: A comprehensive review

Cotton is primarily cultivated for its commercial fiber, which plays a significant role in India’s agro-industrial sector. It is one of the primary raw materials for producing feed, oil, fiber, and biofuel. Currently, farmers in India widely employ machine harvesters to harvest cotton. However, excessive leaf vegetation poses challenges in boll picking, adversely affecting fiber quality and reducing mechanical harvesting efficiency. Various chemical defoliants are applied to remove leaves before harvesting to address this issue. These defoliants promote leaf shedding, minimize debris in the cotton, and enhance boll opening and picking efficiency. Thidiazuron is a potent hormonal defoliant used in cotton to induce defoliation by increasing ethylene production while inhibiting the synthesis and transport of auxins. Notably, it interferes with the crosstalk between the phytohormones, such as cytokinin and ethylene, which regulates cotton defoliation. The method and timing of defoliant application are crucial for improving cotton harvesting efficiency. This review aims to provide a clear understanding of thidiazuron’s application in synchronizing harvests, ultimately supporting the mechanization of cotton harvesting

Effect of drought on gas exchange and chlorophyll fluorescence of groundnut genotypes

Drought is one of the major threats to groundnut productivity, causing a greater loss than any other abiotic factor. Water stress conditions alter plant photosynthetic activity, impacting future growth and assimilating mobilization towards sink tissues. The purpose of this study was to investigate how drought impacts the photosynthesis of plants and its links to drought tolerance. The influence of reproductive stage drought on photosynthetic activity and chlorophyll fluorescence of groundnut is well studied. The experiment was conducted in Kharif 2019 (Jul-Sep), where recent series in groundnut genotypes (60 nos) sown under rainfed conditions and water stress was created by withholding irrigation for 20 days between 35-55 days after sowing in the field to simulate drought conditions. Imposition of water deficit stress reduced PS II efficiency, which significantly altered the photosynthetic rate in the leaf. Observation of gas exchange parameters viz., photosynthetic rate, stomatal conductance and transpiration rate after 20 days of stress imposition revealed that of all 60 genotypes, 20 genotypes (VG 17008, VG 17046VG 18005, VG 18102, VG 18077, VG 19572, VG 19709, VG 18111, VG19561, VG19576, VG 19620, VG 19681, VG 19688, etc.,) had better Photosynthetic rate, Stomatal conductance. Similarly, PS II efficiency analyzed through fluorescence meter revealed that among the 60 and all the genotypes given above recorded higher value in Fv/Fm. Results obtained from Cluster analysis and PCA confirmed that photosynthetic rate and Fv/Fm is useful parameter in screening adapted cultivars under drought stress. These findings lay the groundwork for a future study to decipher the molecular pathways underpinning groundnut drought resistance

A case study of turbulence in the nocturnal boundary layer during the Indian summer monsoon

Observations from the Cloud-Aerosol Interaction and Precipitation Enhancement Experiment-Integrated Ground Observation Campaign (CAIPEEX-IGOC) provide a rare opportunity to investigate nocturnal atmospheric surface-layer processes and surface-layer turbulent characteristics associated with the low-level jet (LLJ). Here, an observational case study of the nocturnal boundary layer is presented during the peak monsoon season over Peninsular India using data collected over a single night representative of the synoptic conditions of the Indian summer monsoon. Datasets based on Doppler lidar and eddy-covariance are used for this purpose. The LLJ is found to generate nocturnal turbulence by introducing mechanical shear at higher levels within the boundary layer. Sporadic and intermittent turbulent events observed during this period are closely associated with large eddies at the scale of the height of the jet nose. Flux densities in the stable boundary layer are observed to become non-local under the influence of the LLJ. Different turbulence regimes are identified, along with transitions between turbulent periods and intermittency. Wavelet analysis is used to elucidate the presence of large-scale eddies and associated intermittency during nocturnal periods in the surface layer. Although the LLJ is a regional-scale phenomenon it has far reaching consequences with regard to surface-atmosphere exchange processes

Scale interactions near the foothills of Himalayas during CAIPEEX

Scale interactions associated with small scale (<100 km) dynamics might play a crucial role in the distribution of aerosol in the Himalayan foothills region. Turbulence measurements from a horizontal flight path during Cloud Aerosol Interaction and Precipitation Enhancement EXperiment (CAIPEEX) are used to illustrate the scale interactions in the vertically sheared flow below the high-level subtropical westerly jet, which is important in the transport of pollution. Data analysis reveals the three dimensional property of large eddies that scale 10-12 km near the slopes, which could bring pollution from the valley to the Tibetan Plateau through a circulation adhering to the slopes. This circulation has a subsidence region away from the slopes and may also contribute to the buildup of pollution in elevated layers over the Plains. The vertical velocity and temperature spectra from research flight data showed clear indications of (-5/3) slope in the mesoscale range. The isotropic behavior of the velocity spectra was noticed for cloud-free traverses, while this behavior is distorted for cloudy conditions with the enhancement of energy at smaller scales as well as with low frequency gravity wave generation. A high-resolution cloud allowing model simulation over the flight path is used to examine the representation of these dynamical interactions in the numerical model. Based on the analysis of observational data and model inferences, a conceptual understanding of the flow in the region close to the foot hills and its role in the distribution of aerosol and cloud condensation nuclei is presented