D Rajakumar

Abiotic stresses, particularly drought, salinity, heat and heavy metal toxicity, increasingly constrain crop productivity and threaten sustainable food production. Although nanoformulations have demonstrated considerable potential for stress mitigation, the evidence remains fragmented across nanoparticle types, crops, stress conditions and application doses and a critical synthesis linking dose response, underlying mechanisms, multi-omics evidence, field performance and safety is still lacking. This review critically synthesises advances in nanoformulations for abiotic stress management, emphasising dose-dependent responses, physiological and biochemical mechanisms, molecular regulation, multi-omics insights, environmental implications and agricultural applications. Nanoformulations are broadly categorised into metal and metal-oxide, silicon-based, carbon-based, biopolymeric and composite or smart systems to provide a focused assessment of their functional roles. Their stressalleviating effects are primarily associated with enhanced antioxidant defence, osmotic adjustment, photosynthetic protection, ion homeostasis, nutrient utilisation and stress responsive signalling. Quantitative evidence highlights their potential; for example, foliar application of zinc oxide nanoparticles (ZnO NPs) at 100 mg L-1 increased grain yield by 42.2 % and root dry weight by 63.1 % in salt-stressed wheat under experimental conditions. Multi-omics approaches integrating transcriptomics, proteomics, metabolomics and ionomics are increasingly revealing NP–plant interactions and stress-response networks. Their convergence with artificial intelligence (AI)-assisted precision agriculture could further support prediction of stress responses and optimisation of nanoformulation dose, timing and crop-specific application. However, dose standardisation, multi-season and multi-location field validation, NP transformation and persistence, soil microbiome effects, food-chain transfer and harmonised safety assessment remain major challenges. Future research should integrate smart nanoformulations, multi-omics and AI-driven precision deployment with rigorous field and environmental safety validation. Nanoformulations therefore represent a next-generation strategy for precise, sustainable and climate-resilient agriculture.

Fusarium oxysporum f. sp. lycopersici, the causal agent of Fusarium wilt in tomato, posed a significant threat to tomato cultivation. This study investigated the biocontrol potential of yeast isolates and Arbuscular Mycorrhizal Fungi (AMF) against this pathogen. Soil and phyllosphere samples were collected from tomato fields in Tamil Nadu, India, leading to the isolation of 120 yeast strains using serial dilution and leaf imprinting techniques. Morphological characterization grouped the isolates with 35 unique colonies were selected for further analysis. Molecular characterization identified three key yeast isolates: Rhodosporidium toruloides (Y2), Moesziomyces antarcticus (Y14) and Pichia kudriavzevii (Y16). Under pot culture conditions, the combined application of AMF and yeast isolates significantly reduced Fusarium wilt incidence. Treatment T5 (AMF liquid-based inoculum + soil yeast Y14) exhibited the highest root colonization (86.66 %), maximum spore load (10397 spores) and minimal disease incidence (11 %), with an 89 % disease reduction compared to the control. This treatment also enhanced tomato plant growth metrics, including height (121.00 cm), root length (61.10 cm) and antioxidant enzyme activity (peroxidase: 0.392 min/g, polyphenol oxidase: 0.791 min/g). Yield parameters were also improved, with maximum fruit weight (19.45 g) and fruit count (6.24) observed in T5-treated plants.

A field trial was conducted at the Anbil Dharmalingam Agricultural College and Research Institute (ADAC & RI), Tamil Nadu Agricultural University (TNAU), Tiruchirappalli during the Samba season of 2020 and 2021 to evaluate the effect of foliar applications of vermiwash, panchagavya and jeevamrutha on rice productivity. The chosen experimental design was Randomized Block Design (RBD) with three replications, comprising seven treatments. These included the standard recommended fertilizer dose (187.5:50:50 kg NPK ha-1) alone and in combination with either a 2.5 % or 5 % spray of vermiwash, panchagavya, or jeevamrutha. Foliar applications of vermiwash, panchagavya and jeevamrutha were applied at panicle initiation, tillering and flowering stages in the variety TNAU Rice TRY 3. The results demonstrated that combining the recommended dosage of the fertilizers (187.5:50:50 kg NPK ha-1) with 5 % vermiwash foliar spray remarkably enhanced growth parameters such as total number of tillers, plant height and total accumulation of dry matter while also improving physiological traits (e.g., SPAD value) and yield components, including productive tillers, test weight, grains per panicle and both grain and straw yield.

An investigation was carried out at Tamil Nadu Agricultural University to utilize tapioca waste from the sago industry, a major waste left unutilized, which may be effectively used for bio ethanol production. Sago industry waste is abundantly available in Tamil Nadu, India, especially in the southern belt comprising of Salem, Erode and Bhavani. In the present study, amylase and the chemical agents HCl and H2SO4 were used separately to determine the most effective saccharifying agent. In comparison with different concentrations (0.1 to 0.8 N) of HCl and H2SO4 treatments, the amylase enzyme at a concentration of 67.5 Ug-1 of 0.6 ml for 60 hr at a temperature of 45 0C served as effective saccharifying agent. It effectively recovered reducing sugar level of 80.2 % from sago industry wastes. The saccharified substrate was subjected to fermentation with an effective yeast strain Saccharomyces cerevisiae YS10 isolated from sugarcane molasses. In the cell free extracts, alcohol recovery of 16.8 % was noticed in sago industry wastes after 15 days of fermentation. Thus, proving its potentiality in the current scenario of recycling the sago industry wastes into bioethanol as a gift to biofuel ultimately to mankind by which the current alarming problem of price rise and demand in the fuel sector can be minimized.

Conservation agriculture (CA) is an approach to optimize farm and watershed performance. It integrates local and national economic systems while considering societal, environmental and institutional frameworks. This approach engages value chains supported by public, private and civil sectors. CA seeks to harmonize the use of natural resources with population needs, employing sustainable intensification to meet human demands effectively and preventing the loss of arable land. Conservation agriculture directly influences all sustainable development goals (SDGs) by leveraging the core principles of minimum soil disturbance, permanent soil cover and crop rotation. Conservation agriculture can prove to be a viable option for meeting the targets of the sustainable agenda. This practice supports environmental, social and economic justice, which creates a holistic developmental route that supports the burgeoning population. Conservation agriculture relies on a knowledge-based strategy to reduce production costs, enabling farmers to adopt new technologies more readily. While CA demonstrates significant benefits across scales, its adoption remains constrained by socioeconomic factors and limited mechanization in the smallholder context. Advancing CA requires a multidisciplinary, participatory research paradigm coupled with policy support, institutional support and capacity building for farmers. CA offers a sustainable framework that ensures sustainable intensification and environmental stewardship in the long term.

An experiment was conducted during 2021 and 2022 in Anbil Dharmalingam Agricultural College and Research Institute, TNAU, Tiruchirappalli, to know the overall allelopathic impact of horse purslane on the germination and seedling growth of rice, ragi, maize, green gram and sunflower. A Completely Randomised Design (CRD) was used to test 6 treatments, including a control and 1%, 2%, 3%, 4% and 5% concentrations of horse purslane whole-plant extract, with 4 replications. Seed germination and subsequent growth and development of selected crops were negatively affected by the extract of horse purslane. The minimum germination was recorded in 5% horse purslane extract, while maximum germination was recorded in control. A consistent decline in germination percentage was observed with increasing extract concentrations. The extract of horse purslane significantly reduced the root length, shoot length, seedling length and seedling vigour index (SVI) of the tested crops. The highest seedling mortality rates were observed at the 5% extract concentration, with values of 83.8%, 78.9%, 47.3%, 51.6% and 81.3% for rice, ragi, maize, sunflower and green gram respectively. The study indicates that horse purslane needs to be controlled effectively in the cropped fields, otherwise, it could reduce the growth and development of field crops. The allelochemicals in horse purslane present significant opportunities for further research on their impact on other weed species, which could contribute to the development of effective weed management strategies in field crops.

The evolution of weed management strategies from basic cultural techniques to novel, integrated approaches reflects technological advancements that promise further improvements in weed management strategies, fostering more efficient and eco-friendly farming practices. Using legume crops as living mulches for weed suppression has gained considerable attention in agricultural systems. This method involves strategically planting leguminous cover crops as intercrops to inhibit weed growth and improve soil health, potentially boosting crop yields through reduced weed pressure and enhanced nutrient availability. The successful implementation of living mulches requires careful selection of crop species, optimal planting density, and appropriate management practices. Choosing compatible legumes, optimizing planting geometry and employing suitable termination methods are essential for maximizing the weed-suppressing and soil-enhancing benefits of living mulches. The efficacy of intercropping systems in controlling weeds largely depends on intercrop components' growth rate and duration. Weed management strategies rely on understanding plant interactions, including the competitive ability of main crops at various growth stages to inhibit weed expansion. While intercropping shows promise for enhancing crop dominance over weeds, weed control efficiency varies among different intercrops due to factors affecting the intercrop-weed relationship. Smallholder farmers find this practice appealing for improving labour productivity and land use through intensification and resource utilization for maximum yield. Research on developing genotypes suitable for weed suppression and studies on combined herbicide applications and optimal dosage determination for effective control of mixed weed flora is necessary. The shift towards integrating pulse crops as a cornerstone in weed management strategies presents a promising avenue for research and application. The comparative analysis underscored in this review showcases the capacity of legumes to offer a viable alternative to synthetic herbicides and mechanical controls, paving the way for their increased adoption in diverse farming systems.

Conventional monocrop rubber farming, while profitable, has led to significant environmental and socio-economic issues. These include deforestation, reduced soil fertility, loss of biodiversity, and increased carbon emissions. Economically, smallholder farmers face risks due to fluctuating rubber prices and income dependency on a single crop. This situation has resulted in low incomes, labour shortages, and, in some cases, abandonment of rubber plantations. Intercropping, or modern rubber agroforestry, offers a promising solution to these challenges. This approach involves planting other crops or trees alongside rubber, increasing revenue, enhancing soil properties, conserving moisture, reducing erosion and improving overall rubber crop yield. Various crops such as fruits (Salaca palm, gnetum, banana and lemon), vegetables (Cucumber, arrowroot, french bean, chilli, mung bean, broad leaf pumpkin, yam, cowpea and egusi melon), spices (Ginger, turmeric, coriander, fenugreek, black pepper, vanilla, cinnamon and nutmeg) and medicinal plants (Sarpagandha, kalmegh, lesser galangal, satavar and long pepper) can be successfully grown with rubber. However, implementing intercropping systems comes with challenges, including potential adverse effects on rubber growth and yield if not appropriately managed. Farmers must implement good agricultural practices and integrated farming strategies to achieve sustainable economic and ecological benefits from rubber-based intercropping. This includes careful selection of cultivars, optimal planting and spacing, regular maintenance and balanced fertilizer application. This review explored essential intercropping practices and highlighted successful case studies within rubber plantations. While more complex than traditional monocropping, a well-managed intercropping system can provide diverse income sources, improve agro-biodiversity and contribute to more sustainable rubber farming practices.

Aims: This study aims to document indigenous technical knowledge (ITK) practices used by farmers in the Tirunelveli district for managing pests and diseases in agricultural crops. It focuses on understanding traditional methods and their relevance in sustainable pest and disease control. Study Design: This is a descriptive field study employing a mixed-method approach, combining a literature review and qualitative data collection from farmers. Place and Duration of Study: The study took place in Tirunelveli district of Tamil Nadu, India. The research was conducted over three months from January to March. Methodology: The research was conducted in three phases 1) Literature Review: Existing studies on indigenous pest and disease management techniques in the region were reviewed. 2) Data Collection: Interviews and focus group discussions were held with farmers to gather traditional knowledge on pest and disease control practices. 3) Data Analysis: The collected information was analysed for common practices and evaluated for effectiveness. Results: The study uncovered numerous indigenous techniques, including the use of neem leaves, cow urine, and plant-based remedies for pest control. Out of 150 farmers interviewed, 80% used traditional methods, with 60% reporting success in reducing crop damage. These practices were found to be cost-effective and eco-friendly, reducing dependence on chemical pesticides. Conclusion: The research highlights the potential of ITK in sustainable agriculture particularly for pest and disease management. It underscores the importance of preserving and promoting these traditional methods as viable alternatives to modern chemical practices.