Tamil Nadu Agricultural University Research Articles

Enhancing Cotton Production and Sustainability through Multi-Tier Cropping Systems: Growth, Efficiency, and Profitability Analysis

Intercropping presents an opportunity to optimise land use and resource efficiency in cotton cultivation, particularly for small and marginal farmers facing climate-related challenges and rising input costs. This study explores the potential of intercropping short-duration vegetables with cotton to transform this production system into a more economically viable and sustainable one. The study was conducted in the Cotton Department of Tamil Nadu Agricultural University in Coimbatore during the winter irrigated season, from August to January, in both 2020 and 2021. The growth, yield parameters, equivalent yield (3645 and 4234 kg ha−1), and net return (Rs. 123,434 ha−1 and Rs. 154,034 ha−1) were higher in the intercropping system with the paired row planting of Bt cotton with two rows of cluster bean. Upon comparing sole cropping and the paired row method of planting, it was found that adopting the paired row system of planting Bt cotton with two rows of cluster bean was highly profitable in all aspects of crop production. Therefore, the adoption of paired row cropping systems with compatible intercrops that promote synergistic effects on the main crop should be considered for enhancing overall productivity, as well as sustainability.

Piloting Pulse Producer Support System Through ICT Enabled Services for Enhanced Climate Resilience

Background: In peninsular India, the frequency of climate-related risks is significantly lowering agricultural productivity and farmers’ standard of living. Reducing losses in the agriculture sector requires precise and timely weather information, weather based advisories on crop production, protection and post-harvest. Disseminating agromet advisories directly to the farmers using ICT tools allows farmers to adopt appropriate corrective measures, minimize loss and ensure climate resilient agriculture. In this sense, the Tamil Nadu Agricultural University established an Automated Agromet Advisory Web cum Mobile App (TNAU-AAS) in 2018, which sends location, crop and stage specific agromet advisories directly to farmers’ mobile App. Methods: TNAU-AAS App was evaluated in pulse crops as “Piloting pulse produce support system through ICT enabled services” between 2019 and 2021 in three TNAU centers under three different eco systems namely irrigated (Coimbatore), rice fallow (Aduthurai) and rainfed (Kovilpatti). Pulse growing farmers were registered in this smartphone application for agromet advisory based response farming. Result: The TNAU-AAS App had delivered approximately 10-12 advisories to each farmer, tailored to their unique crop and stage during the cropping period. Survey results inferred that the farmers received timely notifications on their mobile phones, 2-3 days in advance, which assisted them in preplanning. Occurrences of pests and diseases were well aligned (68-83%) with TNAU- AAS recommendations and the climate vulnerability of non AAS farmers is more than AAS farmer. According to partial budget analysis, the irrigated, rice fallow and rainfed black gram farmers have gained Rs. 2800, Rs. 2300 and Rs. 1900 per ha, respectively. It is concluded that the ICT-enabled agromet advisory system guarantees timely alerts, boosts labor and land productivity, lowers input loss and shields crops from weather-induced pests and diseases as well as climatic variability risk.

Influence of coir pith application on soil moisture distribution with different irrigation regimes of aerobic rice (Oryza sativa) cultivation under trickle irrigation system

An experiment was conducted during the summers of 2019 and 2020 at the AICRP Water Management field, Tamil Nadu Agricultural University, Madurai, Tamil Nadu to study the effect of coir pith application on soil moisture distribution of aerobic rice (Oryza sativa L.) with different irrigation regimes. Treatment consisted of 3 irrigation regimes, viz. I1 , Trickle irrigation at 120% Pan Evaporation (PE); I2 , 100% PE, and I3 , 80% PE. Experiment separately, maintained the surface irrigation of IW: CPE 1.20 as control. The well-composed coir pith @375 kg/ha was spread over the raised beds and leveled well with surface soil. Soil samples were collected in vertical and horizontal directions for determining soil moisture by gravimetric method. Soil moisture appropriation was plotted graphically as contour maps used by the surfer. Results revealed that trickle irrigation at 120% PE with coir pith application improved the yield attributes of aerobic rice compared to surface irrigation (IW: CPE 1.20) owing to coir pith’s favourable hydrological and physical properties to hold and spread the water in the raised bed area.

Association Analysis in Rice Germplasm Lines for High Temperature Tolerance

Background: Relative to other abiotic factors like salinity and drought, breeding rice cultivars that are resistant of high temperatures has received a little attention. The purpose of this study is to find parents and genotypes that are suitable for utilizing in high temperature stress breeding program. Methods: The genetic material for this study comprised of a set of germplasm collections (293 accessions) from different sources such as International Rice Research Institute germplasm. These populations were raised at the Department of Rice, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore. The Heat tolarance Indices (TOL) viz., Heat tolerance index (HTI) and Heat susceptibility index (HSI) and association analysis were estimated among germplasm lines for yield attributes under normal and high temperature stress condition. Result: Out of 293 genotypes, sixty nine genotypes significantly exceeded for both HTI and HSI. Association studies revealed that, single plant yield had highly significant and positive association with panicle exertion, number of total tillers per plant, number of productive tillers per plant, panicle length, number of filled grains per panicle and total dry matter production. Spikelet sterility and high temperature susceptibility index had highly significant and negative association with single plant yield. Number of productive tillers had significant and positive correlation with total dry matter production, panicle length, number of filled grains per panicle, days to maturity, hundred grain weight, grain breadth and high temperature susceptible index. Hence these traits may be considered as selection indices for yield and high temperature tolerance improvement programme. Hence it may be possible to combine single plant yield and heat susceptibility index by specific breeding programme for high temperature tolerance in rice.

Performance of little millet (Panicum flexuosum) based cropping system for rainfed agro ecosystems: A path to sustainable crop diversification

An experiment was conducted during 2019, 2020 and 2021 at Centre of Excellence in Millets, (Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu), Athiyandal, Tiruvanamalai, Tamil Nadu. to study the performance of little millet (Panicum flexuosum Retz.) based cropping system for rainfed agro ecosystems for north-eastern part of Tamil Nadu. The experiment was laid out in randomized block design (RBD) comprised of 9 treatments, viz. T1, Little millet + Redgram [Cajanus cajan (L.) Millsp.] (4:1)-Moth bean [Vigna aconitifolia (Jacq.) Marechal]; T2, Little millet + Redgram (4:1)-Blackgram [Vigna mungo (L.) Hepper]; T3, Little millet + Redgram (4:1)-Horsegram [Macrotyloma uniflorum (Lam.) Verdc.]; T4, Little millet + Redgram (6:2)-Moth bean; T5, Little millet + Redgram (6:2)-Blackgram; T6, Little millet + Redgram (6:2)-Horsegram; T7, Little millet + Redgram (8:2)- Mothbean; T8, Little millet + Redgram (8:2)-Blackgram; T9, Little millet + Redgram (8:2)- Horsegram, with three replications. The good quality seeds of little millet (CO 4), redgram (Paiyur 2), horsegram (Paiyur 2), blackgram (VBN 3) and mothbean [TMV (Mb) 1] were used. The result shows that the higher yield for little millet and intercropped redgram was recorded in T9 (985 and 362 kg/ha) followed by T7 (853 and 356 kg/ha) and T8 (834 and 337 kg/ ha). The 8:2 row ratio exhibited the highest little millet equivalent yield when compared to 6:2 and 4:1 row ratio. The highest economic return and benefit cost (B:C) ratio was observed in T9 with gross return of ₹60,962/ha, net returns of ₹35,362/ha and B:C ratio (2.38). This was followed by T7 which had gross returns of ₹51,314/ha, net returns of ₹25,989/ha and B:C ratio (2.10).

Influence of deficit irrigation and nano NK application on root dynamics, physiology and WUE of transplanted rice (Oryza sativa)

A field experiment was conducted during the rainy (kharif) (June–September, 2022) and winter (rabi) (December 2022–March, 2023) seasons at Agricultural College and Research Institute (Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu), Madurai, Tamil Nadu to study the effect of irrigation methods and nutrient management strategies on the growth of roots, physiological aspects, yield and water use efficiency of transplanted rice (Oryza sativa L.). Experiment was conducted in a split-plot design comprised of 3 irrigation methods, viz. Irrigation at 15 cm depletion of water level in field water tube (M1); Alternate wetting and drying (M2); Conventional flooding (M3) in main plot and 7 nutrient management strategies, viz. Application of 50% N + nano urea as foliar spray (S1); 75% N + nano urea as foliar spray (S2); 50% K + nano potash as foliar spray (S3); 75% K + nano potash as foliar spray (S4); 50 and 75% N and K + nano urea and potash as foliar spray (S5); 100% RDF (S6); and absolute control (S7) in sub plot, replicated thrice. Results indicated that under M1S2, root characteristics like length, volume and dry weight were notably higher. Physiological attributes such as stomatal conductance, transpiration and photosynthetic rate recorded high with M2S5. However, the maximum yield and water use efficiency were observed with M2S5. In conclusion, the treatment combination M2S5 is considered as practical recommendation for farmers in the Periyar Vaigai command area, ensuring optimal yield while economically utilizing water and fertilizers.

Exploring the best nutrient management options for improving the maize yield for future climate change scenario with DSSAT crop simulation model in century old Permanent Manurial Experiment

Increasing the C sequestration potential and higher soil organic carbon stocks with the application of organic manures will reflect in the improvement of crop productivity. Long-term monitoring approach is essential to evaluate these impacts, especially given the escalating effects of climate change on agriculture. Recognizing this, a 112-year-long Permanent Manurial Experiment (PME) at Tamil Nadu Agricultural University, Coimbatore, India, investigates the influence of application of organic manures. Utilizing the DSSAT crop simulation model, the study assessed the impact of organic manure, specifically NPK + FYM (Farm Yard Manure), on maize yield over 25 years on a sandy-loam Alfisol. Data collected from the field experiment including crop growth parameters, management options, weather, and soil data were used for simulations. Results showed a 93.8% agreement between simulated and observed yields, endorsing NPK + FYM treatment with a 20% increase in grain yield by 2032 compared to using 100% NPK alone. Furthermore, the study explored future climate change scenarios’ impact on maize yield. It highlighted that NPK + FYM consistently outperformed other treatments, emphasizing its efficacy in increasing the yields under changing climatic conditions. This approach emerges as promising for enhancing carbon sequestration, elevating soil organic carbon stocks, and significantly improving crop productivity. In conclusion, adopting the NPK + FYM treatment is recommended to achieve optimal maize yield outcomes, surpassing the effects of using NPK or FYM independently. This research signifies the potential of combining organic manures with synthetic fertilizers in sustainable agriculture amid evolving climate challenges.

Spectral Analysis of Pink Mealy Bug Damaged Mulberry Plants Using Hyperspectral Radiometry

Mulberry (Morus spp.) foliage forms a sole food to silkworms, Bombyx mori L. Its quality plays a pivotal role in superior silk fiber production. Like any other plants, mulberry is susceptible to detrimental diseases and infested by insect pests. Many sucking pests cause damage to mulberry among which, pink mealybug causes severe damage leading to significant loss in mulberry leaf yield (12-25 %). Conventional approaches to assess and manage damage caused by pink mealybugs demand substantial manpower and expertise, resulting in time-consuming and inefficient processes. However, leveraging modern tools and technologies like remote sensing has emerged as a remarkably effective strategy for crop protection and management.Specifically, hyperspectral remote sensing proves invaluable by furnishing insights into the biophysical and biochemical traits of crops. This is achieved through the recording of narrow wave bands that reflect specific plant characteristics. The main objectives were to understand the spectral reflectance characteristics of healthy and pink mealy bug damaged mulberry crops, to identify the optimal spectral bands and vegetative indices for detecting pink mealy bug damage in mulberry and to explore the feasibility of estimating pest damage levels based on the spectral properties of mulberry crops. Top of FormAt the mulberry garden of the Department of Sericulture, Tamil Nadu Agricultural University (TNAU), Coimbatore, studies were conducted on spectral analysis of pink mealy bug damaged mulberry plants using hyperspectral radiometry during 2018. In this trial, at 15-day intervals during the active damage stage, the percentage damage was observed in plots infested with pink mealy bugs and those that were healthy. Measurements of spectral reflectance across various wavelengths and vegetation indices (VIs) were taken using a hyperspectral radiometer. The analysis included evaluating the sensitivity of different spectral bands and VIs to pink mealybug damage, along with employing correlation and regression analyses between the extent of pest damage and the VIs. The findings revealed distinct differences in the spectral reflectance profiles of mulberry plants compared to their healthy counterparts. Typically, affected plants exhibited increased reflectance in the red (620–680 nm) and green (520–590 nm) bands and reduced near-infrared (NIR) reflectance (770–860 nm). The average values of the Normalized Difference Vegetation Index (NDVI), Green Red Vegetation Index (GRVI), and Ratio Vegetation Index (RVI) were significantly lower in the pink mealybug-damaged plants across all measurements. Notably, red reflectance demonstrated the greatest sensitivity to pink mealybug-induced damage. The study highlighted the Simple Ratio (SR) index as particularly effective for identifying pest damage. Damage estimation by pink mealybugs was refined using linear regression models based on spectral indices, specifically NDVI, RVI, and GRVI. The correlation intensity analysis pinpointed the green region at 516.73 nm as showing the most significant negative correlation (r = -0.02), whereas the highest positive correlation with pink mealybug damage was observed in the NIR region (r = 0.77), underscoring the precise wavelengths and indices most indicative of pest impact. Thus, using hyperspectral radiometry identification of damage caused by pink mealy bug possible, through analysis of spectral bands and indices.

Assessing Genetic Relationships, Trait Associations and Diversity Patterns in Sorghum Germplasm Through Correlation, Cluster and Principal Component Analysis

Background: The loss of biodiversity has a significant impact on the fundamental services provided by ecosystems to humanity, including plant development and genetic improvement. Germplasm serves as the foundational material for identifying genetic variations. In this context, the examination of sorghum germplasm diversity has been conducted. Methods: The study involved 86 different sorghum germplasm samples that were assessed alongside three control groups, each replicated three times, during the Rabi season of 2021. This evaluation was conducted using augmented block design I (ABD I) at the Department of Millets, Tamil Nadu Agricultural University in Coimbatore. Result: The results of the Pearson correlation analysis revealed significant relationships notably, traits such as plant height, number of leaves, panicle length, panicle width, panicle weight, hundred seed weight and dry fodder yield exhibited positive and significant correlations with grain yield per plant. Cluster analysis identified four distinct groupings among the 86 accessions, with clusters 1 and 4 displaying the greatest diversity. Principal component analysis indicated that PC1 accounted for the largest variability. The genotypes were identified through PCA analysis is having greater variation and better performance. The findings of this study suggest that the identified sorghum genotypes could serve as valuable genetic resources for enhancing sorghum productivity in dry and semi-arid regions, particularly in the face of unpredictable climate change.

Field Performance of Sesame Varieties under Rainfed Ecosystem in Southern Tamil Nadu, India

In Pudukottai district, sesame is cultivated in 3,000 ha and farmers are predominantly growing very old sesame variety TMV 3. This variety is more susceptible to pest and diseases which leads to increased cultivation cost towards plant protection measures as well as reduced yield and income. To overcome this problem, Krishi Vigyan Kendra, Tamil Nadu Agricultural University, Pudukkottai conducted On Farm Testing (OFT) in sesame varieties for promoting the high yielding varieties. Fifteen farmers were selected in different locations of Thiruvarankulam block, Pudukkottai district in Tamil Nadu. Critical inputs of seeds of sesame varieties like TMV 7 and G.Til 10 were distributed to the farmers. The plant physiological and yield parametersviz., plant height (cm), No. of branches, No. of capsules/ branch, capsule length (cm), seeds per capsule, Yield (q/ha) and BC ratio were recorded. The results revealed that, Among the sesame varieties tested, TMV 7 was recorded the maximum plant height (125 cm), number of branches (6.6), number of capsules per plant (43.5), capsules length ( 3.3 cm), No of seeds per capsule ( 57) which resulting in the highest yield of 7.8 q/ha followed by sesame G.Til 10 which recorded more plant height (120 cm), number of branches (6.0), number of capsules per plant (38.2) capsules length ( 3.1 cm), No of seeds per capsule ( 51) and yield of 7.3 q/ha compared to farmers variety cultivating variety TMV 3 which registered the lowest plant physiological parameters and yield (6.4 q/ha). The maximum B:C ratio was recorded in sesame variety TMV 7 (3.12) followed by G.Til 10 ( 2.92) over the variety TMV 3 (2.84). From this trial, it was concluded that, farmers are satisfied with the sesame TMV 7 variety for cultivation due to its low pest and disease incidence, higher yield and BC ratio.

Phytochemical profile of onion (Allium cepa) var. aggregatum: Comparative study of TNAU varieties with a local indigenous

Aggregatum onion (Allium cepa L. var. aggregatum Don.) is widely grown and consumed in southern India. Present study was carried during 2020–23 at Anbil Dharmalingam Agricultural College and Research Institute (Tamil Nadu Agricultural University), Tiruchirappalli, Tamil Nadu to map the metabolites and other dietary nutrients contributing to nutraceutical potentials between indigenous varieties and aggregatum onions varieties of Tamil Nadu. Experiment consisted of Co (On) 5 and Co (On) 6 (Tamil Nadu Agricultural University released varieties) and an indigenous variety from Perambalur (PL), Tamil Nadu. In the present study, metabolites of all the 3 varieties were mapped with the GCMS/MS, and the PL was shown to have high phytonutrients with health benefits. Further, in UHPLC, quercetin was identified with a sharp, well resolved symmetrical peak for all the three onion varieties with the retention time of 64.5, 65.5 and 64.5 min respectively. The Co (On) 6 is the improved variety of Co (On) 5 with a quercetin content of 75.05 ± 0.30 mg/kg, followed by PL (11.11 ± 0.51 mg/kg). However, the native cultivar PL (4.52 ± 0.15 mg/kg) has the highest anthocyanin content followed by Co (On) 6 (4.00 ± 0.10 mg/kg). This study therefore, provides preliminary information on metabolites and phenolics in the selected onion varieties of Tamil Nadu.

Drone based herbicide application in greengram (Vigna radiata)

An experiment was conducted during winter (rabi) season of 2023 at Anbil Dharmalingam Agricultural College and Research Institute, (Tamil Nadu Agricultural University), Tiruchirappalli, Tamil Nadu to assess the effect of drone based herbicide application in greengram. Results showed that drones could be effectively used for spraying of pre-emergence herbicide to control weeds and increase the yield of greengram. Further, application of pendimethalin 0.75 kg/ha with spray fluid of 60 litre/ha precisely through drones controlled the weeds effectively (WCE of 81.8%), increased grain yield, saved herbicide dose and spray fluid to the tune of 6.9%, 25% and 88% respectively than manual spray of pendimethalin 1.0 kg/ha with spray fluid of 500 litre/ ha. Thus, application of pendimethalin 0.75 kg/ha with spray fluid of 60 litre/ha was considered as the optimum dosage and spray fluid for drone spray to control weeds, increase grain yield and profit in greengram, considering the reduced dose of herbicide as well as the labour scarce situation.

Physiological parameters and nutrient uptake in unpuddled machine transplanted rice (Oryza sativa) in combination with alternative wetting and drying

A field study was carried out during rabi (winter) seasons of 2018–19 and 2019–20 at Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai, Tamil Nadu to study the effect of four different crop establishment methods, viz. manual transplanting; transplanting of rice seedling in puddled soil using machine; transplanting of rice seedling in non-puddled soil using machine; and direct sowing combined with four different irrigation treatments, viz. farmers practice; irrigation following the development of a hairline crack; irrigation when water level descents 5 cm; and 10 cm below soil surface on physiology of rice (Oryza sativa L.). Experiment was conducted in a strip plot design replicated thrice. The study revealed that nutrient uptake and physiological parameters were found to be maximum with seedlings of rice crop transplanted in non-puddled soil using machine combined with irrigation following the development of a hairline crack. Seedlings of rice crop transplanted in non-puddled soil using machine combined with irrigation once the water level descends to 5 cm beneath the soil surface, had a significant positive influence on rice yield during both the years. It also recorded higher photosynthetic rate and improved physiological parameters, and yield even with minimum use of water. So, it may be recommended as the best alternate method of rice cultivation compared to conventional method where the rainfall is deficit.

Forage Nutritive Quality, Yield and Quantitative Analysis of Leguminous Fodder Cowpea-Maize System as Influenced by Integrated Nutrient Management in Southern Zone of India

Background: A significant impediment to the advancement of animal husbandry in India is the insufficient availability of green fodder throughout the year. The nutritive quality of forages is heavily influenced by farm-level management practices. Consequently, there is a pressing need to enhance productivity through the implementation of proper agronomic practices. The nutrient management in fodder-based cropping sequence is a key to maximize the fodder production and its quality. Methods: A field experiment was conducted using a randomized block design, consisting of twelve treatments incorporating various organic sources of nutrients. The experiment was replicated thrice during Kharif and Rabi season 2020-22 at Department of Forage Crops, Tamil Nadu Agricultural University, Coimbatore. The treatments included different proportions (100, 75, 50 and 25%) of the recommended dose of nitrogen applied through FYM, vermicompost and bio compost. Result: The experiment results of the three years study revealed that application of 50% RDN through FYM+ 50% RDN through vermicompost recorded the higher green fodder yield of 691 q/ha, dry matter yield of 130.7 q/ha and crude protein yield of 19.3 q/ha. Correlation and regression analysis also indicated that the growth and yield attributes had a positive impact on the fodder yield. Hence it can be recommended that application of FYM and vermicompost (50 and 50% RDN) found better source of organic nutrients for achieving sustainable and economical fodder yield with quality in fodder cowpea-maize cropping system.

Optimizing Banana Crop Productivity: Effects of Nitrogen Levels and Plant Growth Regulators on Chlorophyll Dynamics in Ney Poovan Cultivar

The present study highlights the Effect of different nitrogen levels and plant growth regulators on Total chlorophyll content and chlorophyll stability index of banana cv. Ney Poovan. A field experiment in banana cv. Ney Poovan was conducted with various levels of nitrogen and plant growth regulators at Orchard, Tamil Nadu Agricultural University, Coimbatore. The experiment was laid out in the complete Randomized Block Design with four main plot and eight sub plot treatments which are replicated thrice. Significant differences among the different treatments in growth and physiological parameters was observed. The results reveled that application of various levels of nitrogen and plant growth regulators 200 g N plant-1 (60g + 100g + 40g N plant-1 at 3,5 and 7 MAP respectively + Urea 2% foliar spray + Salicylic acid (SA) 100 ppm @ 3,5 and 7 MAP respectively i.e. M4S5 recorded the highest chlorophyll content (1.40 mg g-1) and chlorophyll stability index (72.58) which was on par with the M3S5 : 200 g N plant-1 (60g + 100g + 40g N plant-1 at 3,5 and 7 MAP respectively)+ Salicylic acid (SA) 100 ppm @ 3,5 and 7 MAP.

Influence of Growth Regulators Application on Seed Development and Maturation in Pigeonpea (Cajanus cajan (L.)

The experiment was carried out at National Pulses Research Centre (NPRC), Vamban, Tamil Nadu Agricultural University to assess the effect of growth regulators foliar sprayon seed development and maturation in Pigeonpea VBN (Rg) 3. Plant growth regulators viz., GA3 (200 ppm) and chlormequat chloride(CCC) 200 ppm were sprayed at vegetative (65 DAS) and flowering stage (80 DAS). The plants without any foliar spraying treatment considered as control. When 50 percent of the plants in a population have reached bud initiation stage, the buds were tagged and collected at five days interval from 5th day upto45th days after initiation (DAI). The variation in pod colour, changes in pod length and weight, seed fresh and dry weight, moisture content, germination and seedling vigour were recorded at regular intervals of five days up to 45 days after flower initiation. The results revealed that the maximum pod length, fresh and dry weight of pod and seed, seed germination and seedling vigour was observed in pigeonpea at 30 days after floral initiation (DAI) in chlormequat chloride (CCC) 200 ppm foliar treatment. The control i.e. without any foliar treatment had attained the physiological maturity at 35 DAI by recording all the physiological parameters viz. maximum pod length, fresh and dry weight, seed germination and seedling vigour. In pigeonpea, application of CCC @ 200 ppm as foliar treatmentleadsto attain physiological maturity at 30 days after initiation of flowering (DAI) by recording the highest seed weight, germination and seedling dry weight over control.

The Efficiency of Black Soldier Fly Larvae with Vegetable, Fruit and Food Waste as Biological Tool for Sustainable Management of Organic Waste

This study investigated the sustainable management of wet organic waste using Black Soldier Fly Larvae (BSFL) for an innovative biological approach to waste management. The organic wet wastes such as fruit, vegetable, and food wastes were processed and fed to BSFL larvae from day 5 and the bioconversion process was carried out at Black Soldier Fly Unit, Tamil Nadu Agricultural University for 21 days. Among the three wastes, the highest bioconversion efficiency was recorded in fruit waste with 67% Substrate Reduction, 10.8% Efficiency of Conversion of Digested feed, 5.7% Bio Conversion Rate, and 4.18 Waste Reduction Index after 21 days. Whereas vegetable and food waste achieved similar bioconversion efficiency. The results suggest that BSFL-based bioconversion can be an effective and eco-friendly waste management and resource recovery technique to significantly lower the volumes of organic wet waste while converting it into high-value biomass and leading to a circular economy model.

Pathogenicity and Molecular Analysis of Fusarium Isolates in Nendran and Grand Naine

Fusarium wilt, a devastating disease, poses a significant global threat to the banana industry. This study is aimed to assess the host susceptibility and pathogenicity of Fusarium isolates in tissue-cultured Nendran and Grand Naine banana varieties. Eight isolates were acquired from the Department of Plant Biotechnology at Tamil Nadu Agricultural University, Coimbatore. Among the eight isolates tested, S-6, S-32G, S-56 and S-67 produced disease symptoms in both Nendran and Grand Naine varieties. Subsequently, the pathogen was reisolated from infected tissues displaying vascular discoloration. While the isolate S-6 produced 66.67% of disease incidence in both the varieties, S-32G, S-56 and S-67 produced 100% disease incidence in Nendran and Grand Naine. Molecular analysis confirmed the presence of the Fusarium oxysporum f.sp. cubense pathogen, with an amplicon observed at 260 bp. Furthermore, non-pathogenic isolates may potentially exert direct or indirect effects on pathogenic strains, offering prospects for disease control.

Root Growth, Nutrient Uptake and Soil Enzyme Activity Influenced by Aerobic, System of Rice Intensification and Conventional Method of Irrigation in Rice

Background: The plant roots pay a vital role in the uptake of water and nutrients. This experiment evaluated the changes in root growth and soil enzyme activity with respect to different rice cultivation methods. Methods: The study was carried out during Kuruvai (July-November) 2022 at Wetlands farm, Tamil Nadu Agricultural University, Coimbatore. Experiments were carried out with five treatments viz., T1- 100% Saturation under drip irrigation, T2- 150% Saturation under drip irrigation T3- 200% Saturation under drip irrigation, T4- System of Rice Intensification (SRI), T5- Conventional method. Result: The result of the experiment shows that higher root growth, enzyme activity was observed in SRI method of rice cultivation. Higher grain yields were recorded in SRI method. It can be concluded that most favourable method of rice production.

Genetic Variability, Heritability, Genetic Advance and Association Studies in Blackgram [Vigna mungo (L.) Hepper

Background: In Tamil Nadu blackgram is cultivated in 4.02 lakhs hectare with the production of 2.25 millon tonnes and productivity of 559 kg/ha. Even though it has great importance, blackgram cultivation is ignored as minimum attention is given towards its genetic improvement. There are various reasons for the low production of crop like lack of genetic variability, absence of suitable ideotype, susceptibility to biotic and abiotic stresses and planting in marginal areas of farming. Hence, it is important to improve the productivity of blackgram. Methods: The present investigation was carried out on 44 blackgram genotypes at field experimentation site of Regional Research Station, Tamil Nadu Agricultural University, Aruppukkottai, Virudhunagar District, to study genetic variability, heritability, genetic advance and correlation and path effects of seven important yield contributing traits including yield trait. Result: Highest GCV and PCV value observed for seed yield per plant and for plant height. High heritability coupled with high genetic advance as percent of mean were recorded for plant height and seed yield (kg/ha) and selection of these traits was useful for further improvement in plant breeding programme. Association analysis revealed that seed yield exhibited significant and positive correlated with plant height and number of pods/plant. Yield component traits viz., plant height, number of pods/plant, 100 seed weight and single plant yield were highly correlated among themselves. It was observed that plant height and number of pod/plant had the maximum positive direct effects on seed yield. The indirect effect of plant height on grain yield was positive through days to maturity, days to fifty percent flowering and number of pods per plant. Hence selection of plants based on plant height and number of pods/plant will help the improvement of seed yield in blackgram.