Tamil Nadu Agricultural University Research Articles

Drone-assisted herbicide optimization for energy efficiency, weed control and economics in transplanted rice (Oryza sativa)

The experiment was conducted during summer and rainy (kharif) seasons of 2021 and 2022 at Agricultural Research Station (Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu), Bhavanisagar, Tamil Nadu to evaluate the efficiency, economics and energetics of drone-based herbicide spray (fluid) application in transplanted rice (Oryza sativa L.). During the experiment the application of pre-emergence and post-emergence herbicides was done using drone and knapsack sprayer to assess the weed control efficiency (WCE). Treatments included 3 herbicide combinations, viz. pyrazosulfuron ethyl as pre-emergence (PE); pyrazosulfuron ethyl as pre-emergence (PE) fb bispyribac sodium as PoE; and pyrazosulfuron ethyl as PE fb metsulfuron methyl + chlorimuron ethyl as PoE; and 4 spray fluids applied using drone and knapsack sprayer (25, 37.5, 75 and 500 litre/ha). Weed free and unweeded check plot were used as reference for calculating WCE. Application of pyrazosulfuron ethyl fb bispyribac sodium using knapsack sprayer reduced weed density from 77.74–86.45% and weed dry weight from 89.60–91.40% over unweeded plot. Moreover, it was found on par with drone application of 37.5 litre/ha using herbicides during both the seasons. Interaction effect between herbicides and drone spray fluids was found to be non-significant. Pyrazosulfuron ethyl fb bispyribac sodium application through knapsack sprayer (500 litre/ha) and drone (37.5 litre/ha) produced higher grain yield and straw yield. Higher net return, benefit: cost ratio (2.49 and 2.40), energy-use efficiency (13.44 and 13.40 MJ) and energy productivity (0.414 and 0.416 kg/MJ) were noticed with drone application of pyrazosulfuron ethyl fb bispyribac sodium using 37.5 litre/ha spray fluid in both the seasons. From the experiment, drone application of pyrazosulfuron ethyl fb bispyribac sodium with spray volume of 37.5 litre/ha was found as an effective strategy to manage weeds in transplanted rice and more advantageous in terms of energy-use efficiency and profitability.

Efficacy of new generation herbicide mixtures in irrigated maize (Zea mays)

The experiment was conducted during rainy (kharif) seasons of 2020 and 2021 at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu to study the efficacy of new generation herbicide mixtures in irrigated maize (Zea mays L.). The experiment was laid out in a randomized complete block design (RCBD) consisted of 9 treatments including pre-emergence herbicides, new generation post emergence herbicides and other weed management practices [T1, Weedy check; T2, Weed free check; T3, Spraying of atrazine @1 kg/ha as pre-emergence + Hand weeding on 25 DAS (days after sowing); T4, Spraying of atrazine @0.75 kg/ha as pre-emergence + Spraying of topramezone @25.2 g/ha as post-emergence on 25 DAS; T5, Spraying of atrazine @0.75 kg/ha as pre emergence + Tembotrione @120 g/ha on 25 DAS; T6, Spraying of atrazine @1 kg/ha as pre-emergence + Topramezone @25.2 g/ha on 25 DAS; T7, Spraying of atrazine @1 kg/ha as pre-emergence + Tembotrione @120 g/ha on 25 DAS; T8, Spraying of topramezone @25.2 g/ha + atrazine @0.75 kg/ha on 15 DAS; and T9, Spraying of tembotrione @120 g/ha + atrazine @0.75 kg/ ha on 15 DAS], replicated thrice. The results evinced that application of topramezone at 25.2 g/ha + atrazine at 0.75 kg/ha on 15th day after sowing significantly reduced the weed density and dry weight leading to higher weed control efficiency and lower weed index of 62.0% and 3.1%, respectively, during both the years of study. This treatment resulted in higher grain yield (7675 kg/ha), net returns (₹72884/ha) and benefit cost (B:C) ratio (2.33) in irrigated maize.

Enhancing Blackgram (Vigna mungo L.) Productivity through Good Agricultural Practices in Tamil Nadu, India

Large scale pulse seed production demonstrations on black gram under the TN IAMP scheme conducted by Agricultural College and Research Institute, Tamil Nadu Agricultural University, Vazhavachanur, Tiruvannamalai district, Tamil Nadu, India in 2 cluster villages at 50 farmer’s holdings during 2019-2020 and 2020-2021, respectively. The result and data analysis show an extension gap of 0.09 q/ha over farmers' traditional practices. The results revealed that TNIAMP intervention demonstrated registered higher growth and yield parameters viz., no. of clusters per plant, no. of pods per plant, grain yield and benefit-cost ratio compared to farmer’s practice grain yield and benefit cost ratio. TNIAMP pulse seed production intervention has had a good impact on pulse growing farmers of the Aliyar sub-basin, as they were motivated by good agricultural practices in the TNIAMP intervention plots and yielded an increase of 15.8 % higher than farmer’s practices.

Bridging the Gap: Enhancing Career Readiness for Agricultural Graduates in India

Agricultural Educational institutions are striving to enhance their methodologies to equip graduates with skills that meet diverse industry demands. While graduates are trained in foundational agricultural science, there is a growing recognition that securing suitable employment requires competencies beyond technical expertise. The study identifies notable gaps in these skill sets among graduates, indicating that while educational programs assess technical abilities rigorously, there is room for improvement in developing broader employability skills. The research involved final-year undergraduate students, alumni, and employers from Tamil Nadu Agricultural University (TNAU). A 67-item questionnaire was administered to students, alumni and employers. The 67 items were grouped into 16 skill categories and percentage analysis was carried out for better understanding. The analysis revealed that a significant portion of students (67.12%) are female, reflecting a positive trend in gender participation in agricultural education. However, the preference for government jobs among 85% of students raises concerns about their willingness to explore opportunities in the private sector, which may limit their career options. The study’s findings also reveal discrepancies in perceptions of essential employability skills among students, alumni, and employers. Students and alumni rated "Listening" as the most critical skill, while employers prioritized "Problem Solving and Analytic" skills. Furthermore, the study advocates for robust career guidance programs that encourage students to consider diverse career paths, including the private sector. Additionally, addressing gender disparities in the workforce is crucial to ensure equitable opportunities for all graduates.

Assessment of growth and essential oil profiling in leafy coriander (Coriandrum sativum L.) genotypes

Coriander is a versatile plant prized for its dual role as a culinary spice and a medicinal herb. Leafy coriander, an herbaceous plant, is particularly noted for its rich content of bioactive compounds, such as essential oils, flavonoids, and vitamins. The experiment was conducted at the Department of Spices and Plantation Crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore. A study was conducted using a Randomized Block Design (RBD) with two replications, focusing on critical growth and yield traits. Among the fifteen genotypes evaluated, the CSL1 genotype illustrates superior performance in various growth and yield parameters. Coriander leaves are extensively studied for their antioxidant, anti-inflammatory, and antimicrobial properties, underscoring their significance in nutritional and medicinal contexts. In this research, coriander leaf oil was extracted and analysed using gas chromatography-mass spectrometry (GC-MS) to determine its chemical composition. The GC-MS analysis identified 60 distinct compounds in the essential oil, with the major constituents being 3-dimethylamino acrylonitrile, trans-2-Dodecen-1-ol, Cyclooctane, Decanal, 13-Octadecenal, 9-Decen-1-yl acetate and 2-Propen-1-amine. These results offer valuable insights into the unique chemical profile of coriander leaf oil, contributing to its distinctive aroma and potential applications in flavouring fragrance and therapeutic formulations.

Effect of Land Configuration and Rainfall on Pennisetum glaucum (L.) R. Br. under Saline Irrigation

Field experiment was conducted in Eastern Block Farm of Tamil Nadu Agricultural University, Coimbatore to evaluate the effect of land configuration and rainfall on growth and yield of pearl millet under saline water irrigation in summer, 2024. The study was carried out in split plot design with three main plots (flatbed (M1), ridges and furrows (M2) and raised bed paired row planting (M3)) along with four subplot treatments (direct sowing (S1), 10 Day Old Seedlings (DOS) (S2), 15 DOS (modified dapog) (S3) and 20 DOS (S4)) which was replicated thrice. Water availability is a critical factor in influencing the length of the growing period while water quality significantly influences crop growth and yield. Consequently, rainfall received during the growing period affects plant height, Leaf Area Index (LAI), effective tillers and yield. The cumulative rainfall received 208 mm in 22 days and with 10 rainy days during the crop growth period. Rainfall between 40 to 60 Days After Sowing/Planting (DAS/P) corresponded with Crop Growth Rate (CGR). Among main plot treatments, ridges and furrows (M2) recorded higher plant height (173 cm) and effective tillers (2.6) at harvest. Grain and stover yields (t ha-1) were also higher in ridges and furrows (M2) (3.31 and 6.12, respectively) which was statistically on par with raised bed paired row planting (M3) (3.31 and 6.12, respectively).

Effective weed control through post-emergence herbicides to enhance blackgram (Vigna mungo L.) productivity in South India

Pulses are essential components of vegetarian diet and play a pivotal role in addressing malnutrition by providing a vital source of dietary protein. However, weed competition remains as a significant obstacle to blackgram (Vigna mungo L) production, resulting in 25 to 35% yield losses. A field experiment was carried out at the National Pulses Research Centre, Tamil Nadu Agricultural University, Vamban, Pudukkottai, India during Kharif seasons of 2020 and 2021, to assess the suitable post-emergence herbicides for appropriate weed control in blackgram grown under irrigated conditions. The experimental field was observed to contain notable grass weed flora, specifically Dactyloctenium aegyptium and Chloris barbata, as well as broadleaved weeds, such as Flaveria australica, Cleome gynandra, Eclipta alba, Convolvulus arvensis, Digera arvensis, Vicia spp., and Celosia argentea. The results demonstrated that among the chemical weed management methods, spraying of Fomesafen @ 220 g + Fluzifop p-butyl @ 220 g ha−1 at 20 days after sowing (DAS) as a post-emergence herbicide treatment exhibited superior weed control efficiency, recording 66.80% and 68.53% at 30 and 45 DAS, respectively and recorded higher seed yield of 1088 kg ha−1. Additionally, this method generated 8.1% higher net income and 12.5% more benefit–cost ratio than hand weeding, making it an economically profitable strategy for maximizing blackgram yield and effective labour management.

Assessing population structure and morpho-molecular characterization of sunflower (Helianthus annuus L.) for elite germplasm identification.

Sunflower (Helianthus annuus L.), known for its adaptability and high yield potential, is vital in global edible oil production. Estimating genetic diversity is a key pre-breeding activity in crop breeding. The current study comprised of 48 genotypes which were assessed for their biometrical traits at department of Oilseeds, Tamil Nadu Agricultural University, during the rainy season of 2022. The lines were subsequently characterised using 103 simple sequence repeat (SSR) markers for molecular diversity analysis. The results indicated that the net nucleotide distances indicated varying genetic divergence, with subpopulations II and V showing the highest (0.056) and I and IV the lowest (0.014). Subpopulation IV exhibited the highest heterozygosity (0.352), while subpopulation III had the lowest heterozygosity and a low Fst (0.173). Principal components analysis (PCA) and hierarchical cluster analysis were employed for assessing the morphological diversity, facilitating genotype grouping and parent selection for breeding programs. The first four components cumulatively accounted for 86.72% of the total variation. Cluster Analysis grouped 48 sunflower genotypes into three clusters based on genetic diversity. COSF 13B stands out for its high head diameter, oil content, seed yield, and oil yield based on mean performance of morphological data. Principal coordinate analysis (PCoA) mirrored the groupings from the Neighbor Joining method, with the first three components explaining 27.24% of the total variation. Molecular data analysis identified five distinct clusters among the germplasm. By integrating morphological and molecular marker data with genetic distance analysis, substantial diversity was revealed with the genotypes RHA 273 and GMU 325 consistently demonstrated high oil yield per plant. The genotypes GMU 477, GMU 450, COSF 13B, RHA 102, CMS 1103B, and RHA GPR 58 have been identified as suitable parents for enhancing oil content in sunflower breeding programs. These findings also aid in selecting SSR markers for genotype characterization and in choosing diverse parents for breeding programs.

Physiological and enzyme dynamics of tomato under drought stress

Climate change leads to an increase in the frequency and severity of droughts, which have a negative impact on agriculture by altering plant growth and lowering water availability, placing food production systems at risk of sustainability. In order to improve drought resistance and ensure food security in the face of growing water shortages, this research was conducted to determine the physiological and enzymatic responses of tomato plants to drought stress. This study was conducted at Tamil Nadu Agricultural University, Coimbatore, involving 3 hybrids, viz., H1: EC169966 × LE118, H2: EC177824 × LE118 and H3: Arka Ashish × LE 27, along with their parents, P1: EC177824, P2: LE27, P3: EC169966, P4: LE118 and P5: Arka Ashish, under 50 % and 100 % field capacity conditions in factorial completely randomized design (FCRD) with 3 replications. Results indicated a significant change in physiological and enzymactic activities. Here, the parent P2 and hybrid H2 showed superior tolerance, with higher relative water content, proline, leaf water potential, membrane and chlorophyll stability index. Added to that, the response of enzyme activities including peroxidase, nitrate reductase, catalase, polyphenol oxidase and superoxide dismutase was found to be increase notably in drought-tolerant hybrids and parents, which correlated strongly with physiological markers of drought resistance. These modifications highlight the capacity of some genotypes to preserve photosynthetic efficiency and cellular integrity in water-limited environments. The results highlight the significance of choosing and developing drought-tolerant cultivars in order to maintain agricultural production in areas vulnerable to drought and address issues related to global food security.

Deciphering the Biocontrol Potential of Trichoderma asperellum (Tv1) Against Fusarium-Nematode Wilt Complex in Tomato.

The study assessed Trichoderma spp. as a biocontrol agent for managing wilt-nematode complex in tomato crops, aiming to mitigate yield losses. Fusarium sp. and Meloidogyne sp. were isolated from infected plant samples and confirmed molecularly and morphologically as Fusarium oxysporum f.sp. lycopersici and Meloidogyne incognita. Four Trichoderma spp. procured from the Department of Plant Pathology, Tamil Nadu Agricultural University, India were identified molecularly as Trichoderma asperellum (Tv1), Trichoderma asperelloides (Tasd1), Trichoderma harzianum (Th1), and Trichoderma koningiopsis (Tk1) utilizing ITS and TEF1 primer pairs. Among them, Tv1 effectively inhibited the mycelial growth of pathogen isolates. Furthermore, crude metabolite of Tv1 exhibited similar effects. The mortality rate of M. incognita J2s ranged from 90.48% to 100% after 24-72 h of incubation and inhibition percentage of egg hatching reached 90.20%. The shoot length, root length, fresh weight, and dry weight of the tomato plants treated with Tv1 conidia were increased. In a pot experiment, Tv1 treatment reduced disease incidence by 64.57%, comparable to carbendazim treatment (82.32%). Tv1-treated plants had fewer root galls, egg masses, and J2s per 100 g of roots than the inoculated-untreated control plants. The root-knot index (RKI) was significantly lower in plants treated with carbafuran (1.98 ± 0.047) and Tv1 (3.06 ± 0.086) than in control (4.47 ± 0.109). The bio-control efficiency of Tv1 against M. incognita was 21.04%, and the nematodes' reproductive factor (RF) declined to 0.53 in Tv1 treatment group. Based on the findings above, it was established that Tv1 effectively controlled nematode populations and wilt disease when applied in soil.

A comparative study of drone and manual herbicide application for weed management in wet direct-seeded rice (Oryza sativa L.)

A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore, during the Navarai season (January-April) of 2024 to assess the efficiency of drone-based herbicide application in terms of weed control, energy use, and cost effectiveness in wet direct-seeded rice (Oryza sativa L.). The study compared the effectiveness of weed control using herbicide combinations applied as pre-emergence followed by early post-emergence, with both drone and knapsack sprayer. The treatments included the application of pretilachlor followed by early post-emergence bispyribac sodium, and pyrazosulfuron followed by penoxsulam + cyhalofop butyl, using both drone and knapsack sprayer. Additionally, weed-free and unweeded control plots were included. Results indicated that the application of pretilachlor followed by bispyribac sodium using a drone sprayer significantly reduced weed density and weed dry weight compared to the unweeded plot. This treatment also resulted in a higher grain yield (5286 kg ha-1). Moreover, drone application of pretilachlor followed by bispyribac sodium provided a higher net return (? 51631/ha), benefit-cost ratio (2.17), energy-use efficiency (9.53), and energy productivity (0.30 kg/MJ). The experiment concluded that drone-based spraying of pretilachlor followed by bispyribac sodium is an effective weed management strategy for wet direct-seeded rice, offering superior yield attributes, energy use efficiency, and profitability.

Study on performance of cabbage (Brassica oleraceae var. capitata L.) under different production systems

Coimbatore is located in the western part of Tamil Nadu and nestled against the foothills of the Western Ghats. This region's cool climate and favourable terrain make it ideal for cultivating hill vegetables. Cabbage (Brassica oleracea var. capitata L.) is a significant cole crop known for its high nutritional value. Excessive chemical usage in cabbage cultivation leads to residual effects on soil and produce. This study aimed to identify the best production system for cabbage cultivation in the northwestern parts of Tamil Nadu. An experiment was conducted during the winter season of 2023-2024 at the Tamil Nadu Agricultural University, Coimbatore. The experiment was laid out in a randomized block design (RBD) with four treatments and five replications. The organic farming system exhibited the highest values for plant height (21.47 cm), stalk length (8.49 cm), dry matter accumulation (71.34 g per plant), days to head formation (18.75 days), days to harvest (56.25 days), head diameter (17.70 cm), head compactness (33.91), head weight (945.35 g per plant) and cabbage yield (24.92 t ha-1), surpassing both conventional and natural farming systems. A similar pattern was observed in quality parameters, including TSS (6.54 °Brix), shelf life (12.21 days) and ascorbic acid content (44.26 mg per 100 g). This study highlights an efficient cabbage cultivation system in the Coimbatore region, leading to improved yield, soil health and quality.

Multivariate genetic analysis and diversity assessment in lotus (Nelumbo nucifera) accessions

The present study was carried out during 2019 to 2022 at the Floriculture Research Station (Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu), Thovalai, Kanyakumari, Tamil Nadu to access the genetic variability in lotus accessions (Nelumbo nucifera) collected from 6 diverse locations. The research presents significant insights into the growth and flowering characteristics of these extraordinary aquatic plants and their adaptability to various environmental conditions. The analysis of mean performance showcases noteworthy variations in plant height, leaf dimensions, flowering time and the number of leaves, and flowers/plant across different collection sites, highlighting the profound influence of local environmental conditions on lotus growth. Lotus traits with significant genetic diversity and heritability, presenting opportunities for targeted selective breeding were identified. Principal component analysis uncovers key trait influencers, while cluster analysis categorizes accessions based on similarities, streamlining research and cultivation. Correlation and path analysis unveil relationships among lotus traits, enhancing our understanding of growth factors. D2 cluster composition reveals distinct groupings; Cluster I includes KNn1 and KNn5, Cluster II features KNn2, Cluster III comprises KNn6, Cluster IV contains KNn3, and Cluster V houses KNn4. Genetic divergence analysis identifies the number of flowers/plant as the primary driver of genetic diversity, emphasizing its importance for breeding. It underscores the need to consider both genetic and environmental factors in lotus cultivation and highlights the importance of targeted breeding efforts to unlock the full potential of lotus.

Unveiling the genetic variability, character association and principal component analysis for yield and yield contributing traits in brinjal (Solanum melongena) genotypes

The experiment was conducted during rainy (kharif) and winter (rabi) seasons of 2023 and 2024 at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu to assess 45 brinjal (Solanum melongena L.) genotypes for growth and yield related parameters. The experiment was laid out in randomized block design (RBD) with three replications. The result showed high genotypic coefficient of variance (GCV) and phenotypic coefficient of variance (PCV) values for plant height, number of primary branches/plant, length of fruit and weight of fruit and yield/plant. Whereas, the traits such as days to first flowering, days to 50% flowering, fruit girth, fruit borer infestation and number of fruits/ plant exhibited medium GCV and PCV values. The registered high heritability values ranged from 94.29–99.49% and genetic advance as a percentage of the mean ranged from 19.25–70.25%. Correlation analysis on number of fruits/ plant showed positive and significant association with fruit yield/plant. Principal component analysis showed four principal components with eigen values of unity and accounted for 75.81% of total variance.

Serological and morpho-molecular characterization of papaya ringspot virus (PRSV) infecting the papaya (Carica papaya) in Tamil Nadu

Papaya ringspot virus (PRSV) is wreaking havoc on papaya cultivation, leading to significant crop losses. Present study was carried out during 2022 and 2023 at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu aimed to identify and characterize PRSV in four districts of Tamil Nadu. The incidence of the PRSV ranged from 32–100% in the surveyed districts. Samples displaying symptoms such as mosaic patterns, mottling, yellowing, puckering, shoestring appearance, oily stains on stems and petioles, deformed fruits, and concentric rings on fruits were collected for PRSV confirmation. The preliminary diagnosis of samples using DAS-ELISA showed the presence of PRSV in leaf and fruit skin samples but the absence of the virus in flower and seed samples. The existence of flexuous, filamentous rod- shaped particles measuring 809 nm × 15 nm in the tested leaf sample showed the incidence of Potyvirus, as revealed by transmission electron microscopy (TEM). Molecular characterization of PRSV in leaf and fruit skin samples was carried out using PCR with PRSV coat protein-specific primers, resulting in the amplification of an 850 bp product. Sequencing of the amplified products showed that the partial sequences of isolates CBE1-TN and ANR1-TN were 99.99% identical. Early detection of PRSV is imperative for implementing effective management strategies.

Standardization of Hormone-Based Seed Coating Formulation for Coriander Dosage and Formulation Optimization

Aims: This study aimed to standardize the dosage of hormone-based seed coating formulations to enhance germination and seedling growth in coriander seeds. Study Design: Completely Randomized Design. Place and Duration of Study: Department of seed science and technology, Tamil Nadu Agricultural University, Coimbatore, India. During the year of 2023-2024. Methodology: Coriander seeds were coated with different concentrations of seed coating polymer and germination study was conducted in laboratory using rolled towel method with four replications. Data were analyzed by ANOVA with significance at p ≤ 0.05. Results: The hormone-based seed coating formulation has recorded significantly higher germination% (69%), root length (16.75 cm), shoot length (7.9 cm), dry matter production (0.058 g/10 seedlings), Vigour Index I (1706) and II (3.9) at 10 g polymer/kg of seed and 290 mL of water. Conclusion: Seed Coating with 10 seed coating formulation dissolved in 290 mL of water enhanced the seed germination and seedling growth.

Effects of Hexanal Based Formulation on Shelf Life of Strawberry (Fragaria x ananassaDuch.)

We evaluated the role of ‘Enhanced Freshness Formulation’ (EFF) having hexanal as the main component on shelf life enhancement of strawberry (Fragaria x ananassa) cv. Sweet Charlie. Hexanal based Enhanced Freshness Formulation was sourced from Centre for Agricultural Nanotechnology, Tamil Nadu Agricultural University, Coimbatore. After crop harvest, a laboratory experiment in completely randomized design was done at ambient temperature (about 22-30°C) with 5-treatments (dipping of freshly harvested berries in hexanal of varying strengths)viz., 1 % hexanal for 2.5 min (V1), 1% hexanal for 5 min (V2), 2% hexanal for 2.5 min (V3) and 2% hexanal for 5 min (V4). Undipped berries were considered as control treatment (V5). Fruit firmness, shelf life, physiological loss in weight, decay loss and anthocyanin content were studied. The study revealed that dipping the berries in 2% hexanal for 2.5 min proved most effective to prolong the shelf life of strawberry. Maximum shelf life (5.90 days) and fruit firmness (5.88 N mm-1) were obtained in the most efficacious treatment, thereby extending the marketing period.

Econometric Analysis and Intercropping Nutri-Cereals with Legumes (Urad Bean, Arhar) on Climate Resilience in North Eastern Zone of Tamil Nadu

Background: Nutri cereal - Legume intercrop systems are particularly beneficial in North Eastern Zone of Tamil Nadu, which are characterized by high levels of malnutrition, resource limitation and rainfall variability. These conditions are further exacerbated by climate-related risks and uncertainty. Apart from enhancing water and nutrient use efficiency, improving soil fertility and financial gains, Millet-legume intercrop systems have become a better bet for increased food and nutrition security in marginal farming communities. Methods: A study conducted during the year of 2022 to 2024 at the Center of Excellence in Millet, Tamil Nadu Agricultural University, Athiyandal, Tamil Nadu. The study evaluated various intercropping ratios of finger millet with black gram and red gram across seven treatments, focusing on productivity, compatibility and economic viability. Result: Results indicated that intercropping finger millet with black gram at a 4:1 ratio produced taller plants (92.7 cm), more protective tillers (5.7 per plant), extensive root systems (19.9 cm), and higher chlorophyll content (3.67 mg/g). This combination resulted in the highest equivalent grain yield (2895 kg/ha) and demonstrated a favourable benefit-to-cost ratio (2.84), highlighting its potential for improving profitability and soil fertility. Conversely, intercropping with red gram yielded lower finger millet yields and less favourable economic returns, underscoring the importance of selecting suitable intercrops to maximize agricultural productivity and sustainability.

Variability and Correlation Studies in Dolichos bean (Dolichos lablab L.)

Background: Dolichos bean (Dolichos lablab L.), 2n = 22 is an important leguminous vegetable crop which provides protein, minerals and vitamins. The exploitation of variability is of great importance and is a prerequisite for the effective screening of superior genotypes. Keeping this in view, the present investigation was carried out to assess the variability and correlation for yield and other components which are useful to select the promising genotypes. Methods: The study on variability and correlation in Dolichos Bean genotypes for yield and quality was conducted at the College Orchard, Tamil Nadu Agricultural University, Coimbatore. Twenty lablab genotypes, sourced from various locations, were planted in a randomized block design with three replications during the kharif and rabi seasons of 2021 and 2022. Observations on growth, yield and quality traits were recorded and analysed for variance, variability and correlations. Result: In the kharif season, Ankur Gold yielded the highest green pods per plant (487.50 g), while Acc.7 yielded the lowest (89.59 g). In the pooled analysis, Ankur Gold (469.80 g) had the highest and Acc.6 (87.49 g) had the lowest green pod yield per plant. The study suggests using a selection index based on the number of racemes per plant, raceme length, number of pods per plant, green pod yield per plant and pod length to identify high yielding lablab genotypes.

Screening of Rice Genotypes for Submergence Stress Tolerance

The experiment was conducted at Department of Rice, Tamil Nadu Agricultural University, Coimbatore to study the effect of submergence on growth of various genotypes of paddy. The genotypes viz., AC1303, AC42088, AC38575, SABITA, NAVEEN, SWARNA Sub1, BLACK GORA, BAJKANI, SWARNA, PARUAT, PAU9, BRAHMANNAKHI, MAHULATA, BVD109, IET-18720, IET-18727 and IC-516009 lines were used for submergence screening. The seeds should be pre-heated at 50°C for 2-3 days for breaking the seed dormancy before sowing. The seeds were directly sown inside the tanks using wet-bed direct sowing method. Each genotype was sown in 2 rows (min.) with 3 replications with a row to row spacing of 20 cm and plant to plant spacing of 15 cm. Germinated seedlings were allowed to grown normally till 20–25 days without submergence stress. The observations like plant height (before and after submergence), Number of plants survived (before and after submergence), survival percentage and total starch content were recorded. The genotypes IET-18727, PAU9 and AC38575 had better survival percentage (80.0 to 86.7%) with higher starch content (6.3 to 6.9 mg g-1) under submerged stress conditions. The genotypes of BVD109 and SWARNA registered lesser survival percentage (26.7% and 26.3%) with starch content of 2.1 mg g-1 among the rice genotypes.