Renewable energy for sustainable development is a subject of a worldwide debate since continuous utilization of non-renewable energy sources has a drastic impact on the environment and economy; a search for alternative energy resources is indispensable. Microalgae are promising and potential alternate energy resources for biodiesel production. Thus, our efforts were focused on surveying the natural diversity of microalgae for the production of biodiesel. The present study aimed at identification, isolation, and characterization of oleaginous microalgae from shola forests of Nilgiri Biosphere Reserve (NBR), the biodiversity hot spot of India, where the microalgal diversity has not yet been systematically investigated. Overall the higher biomass yield, higher lipid accumulation and thermotolerance observed in the isolated microalgal strains have been found to be the desirable traits for the efficient biodiesel production. Species composition and diversity analysis yielded ten potential microalgal isolates belonging to Chlorophyceae and Cyanophyceae classes. The chlorophytes exhibited higher growth rate, maximum biomass yield, and higher lipid accumulation than Cyanophyceae. Among the chlorophytes, the best performing strains were identified and represented by Acutodesmus dissociatus (TGA1), Chlorella sp. (TGA2), Chlamydomonadales sp. (TGA3) and Hindakia tetrachotoma (PGA1). The Chlamydomonadales sp. recorded with the highest growth rate, lipid accumulation and biomass yield of 0.28 ± 0.03 day−1 (μexp), 29.7 ± 0.69% and 134.17 ± 16.87 mg L−1 day−1, respectively. It was also found to grow well at various temperatures, viz., 25 °C, 35 °C, and 45 °C, indicating its suitability for open pond cultivation. The fatty acid methyl ester (FAME) analysis of stationary phase cultures of selected four algal strains by tandem mass spectrograph showed C16:0, C18:1 and C18:3 as dominant fatty acids suitable for biodiesel production. All the three strains except for Hindakia tetrachotoma (PGA1) recorded higher carbohydrate content and were considered as potential feed stocks for biodiesel production through hydrothermal liquefaction technology (HTL). In conclusion, the present investigation is a first systematic study on the microalgal diversity of soil and water samples from selected sites of NBR. The study resulted in isolation and characterization of ten potent oleaginous microalgae and found four cultures as promising feed stocks for biodiesel production. Of the four microalgae, Chlamydomonadales sp. (TGA3) was found to be significantly thermo-tolerant and can be considered as promising feedstock for biodiesel production.

Agroforestry benefits farmers, making it a sustainable alternative to monoculture. To create a viable Eucalyptus clone-based agroforestry system, a field experiment was carried out in Tamil Nadu, India. The economics and changes in the soil qualities were evaluated by growing agricultural and horticultural crops, namely pearl millet, sorghum, maize, sesame, small onions, green gram, and red gram, as intercrops under eight-month-old eucalyptus clone trees using a randomised block design in three replications at a spacing of 3 m × 1.5 m. The plots for the intercrops and the eucalyptus clones were kept apart for comparison. Maize showed the greatest drop in plant height during all the phases, including 30 DAS, 60 DAS, and harvest, while small onions showed the least reduction in plant height. Sesame and small onions showed the greatest drop in dry matter production, whereas sorghum showed the least. In terms of the intercrop yield reduction, maize had the biggest reduction and green gram had the lowest. Red gram had the largest crop equivalent yield, whereas maize had the lowest. The volume of the trees was generally increased more favourably by red gram than by green gram. The intercrops had some effects on the nutrients in the soil. Red gram intercropping had the highest levels of EC, soil organic carbon, available soil nitrogen, available soil phosphorus, and available soil potassium, while the sole tree treatment had the lowest levels. Small onions, red gram, and sesame were the crops; tree + small onion, tree + red gram, and tree + sesame were the intercrop combinations with the highest gross income, net income, and B:C in the intercropping treatment alone. Tree + green gram had the highest land equivalent ratio (LER) and the red gram, sesame, and small onion intercrops were shown to be the most profitable. Although the present study supports a complementary relationship, the lack of awareness among farmers of Eucalyptus allelopathy formed the major limitation.

Moringa (Moringa oleifera Lam.) is an incredible plant with a storehouse of essential nutrients such as proteins, vitamins, minerals, and phytochemicals such as phenols, flavonoids, glycosides, and sterioids. From the qualitative screening, phytochemical was highly present in hydroethanolic extracts. Through hydroethanolic extraction, the recovery of these biomolecules could be achieved throughadvanced novel extraction methods such as microwave-assisted extraction. The main aim of this experimental trial is to optimize three independent factors including power (500W700W), temperature (30C50C), and extraction time (20min40min) consisting of two levels of dependent variables such as extraction yield (EY) and total phenol content (TPC) using Response Surface Methodology (RSM) constructed by Central Composite Design (CCD) with 20 trial runs. The optimized extraction method recorded 14.64 to 17.65 of extraction yield and 63.36 to 76.40mgGA/gram of total phenol content. As a result of the optimization of microwave-assisted extraction, the recovery of biomolecules from the dried moringa leaves is achieved by increasing the extraction temperature and time with the microwave power of the instrument.

Production of guttation droplets in the cultures of Colletotrichum falcatum was often noticed. Hence, formation of guttation droplets, exudation of toxin in guttation, and guttation droplet chemical composition were assessed to find the ecological importance of guttation. Among the tested culture media, more guttation was noticed in oat meal agar medium and host extracts broth medium. Assessing the effect of five different carbon sources on guttation of C. falcatum showed that among solid media, sparse guttation droplets were noticed in glucose-, fructose-, and starch-amended media, whereas in broth cultures except fructose-amended media no other carbon sources induced guttation in mycelium. The guttation phenomenon was noticed only in sporulating mycelia, and it also followed a specific pattern in connection with sporulation. Bioassay of guttation exudates on sugarcane leaves produced pronounced necrotic lesions with large, yellow halo similar to positive control, thus confirming the presence of toxin. The guttation fluid initiated browning symptom on sugarcane leaves at a concentration of 1000 ppm and produced pronounced necrotic lesions of 3.7 cm at 10 000 ppm. The toxicity of crude fraction was thermostable up to 60 C. The gas chromatography–mass spectrometry (GC-MS) analysis of crude guttation droplets identified the presence of 24 compounds belonging to fatty acids, derivatives of fatty acids, flavonoids, flavonoid glycosides, sterols, quinone derivatives, amides, and glycol ethers, and among them fatty acids were dominant. The two compounds, viz., hexadecanoic acid methyl ester and 9-octadecenoic acid (Z) methyl ester, were abundant (18.14% and 17.98%, respectively) and identified as probable toxic compounds.

Fruits play a crucial role in human nutrition by providing essential vitamins, minerals, antioxidants and dietary fiber, which support overall health and help prevent chronic diseases. Although India, being the second-largest fruit producer globally, but faces significant challenges in fruit production, including environmental stress, postharvest losses and the adverse effects of chemical-intensive agriculture. The increasing demand for sustainable farming solutions has led to the exploration of biostimulants, particularly seaweed-based formulations, which enhance plant growth, nutrient uptake and stress tolerance. Seaweed extracts are rich in bioactive compounds such as phytohormones, amino acids and antioxidants. The role of seaweed based biostimulants in modern agriculture is significant, as they positively impact on soil health, plant metabolism and on improving fruit yield, quality and resilience to abiotic stresses, environmental sustainability. Additionally, the application of seaweed extracts in fruit crops, particularly grapes, apples and citrus, has shown promising results in enhancing yield, improving fruit quality attributes and mitigating stress-related damages. The seaweed at 1 g/L was treated as a foliar treatment that can boost the anthocyanin content, increasing the yield and number of berries in grapevine Vitis vinifera L. The foliar application of seaweed extract at 4 mL/L increases the mineral nutrients like nitrogen, potassium, iron and zinc in the leaves of mango Mangifera indica L. The integration of seaweed biostimulants with precision agriculture techniques further strengthens their role in sustainable farming. Future trends in biostimulant research focus on developing cost-effective, environmentally friendly formulations with enhanced bioactivity. This study underscores the significance of seaweed-based biostimulants as a sustainable alternative to chemical fertilizers and pesticides, contributing to improved agricultural productivity while ensuring ecological balance. By adopting such innovative solutions, the agricultural sector can enhance fruit production efficiency, minimize losses and promote long-term sustainability in horticulture.