Seasonal dynamics of arthropods in Lucerne (Medicago sativa L.) and nutritional link to rodent foraging

Lucerne (Medicago sativa L.) is a highly nutritive crop with more vitamins and minerals used as a fodder legume since it is available throughout the year. In the Coimbatore district farmers prefer lucerne as a fodder crop because of its quality, year-round production, and seed yield fetches a high price. The monitoring study on lucerne crop pests, natural enemies and pollinators was conducted at Tamil Nadu Agricultural University, Coimbatore for three seasons from October 2021 to June 2024. The major sucking pests observed in Lucerne were aphids (Aphis craccivora Koch) and stink bugs (Nezara virudula, (L.)) and the natural enemy observed was coccinellid predators (Cheilomenes sexmaculata (Fabricius)). Natural enemies such as the Ladybird beetle (Coccinella repanda Thunberg) and Paper wasp (Polistes exclamans Vierick) were also documented as crucial in regulating these pest populations. The study also observed a diverse range of pollinators including the Alfalfa Leafcutter bee (Megachile rotundata (Fabricius)), various butterflies, and several species of bees that are vital for effective pollination and enhanced crop quality. The population of aphids and stink bugs ranged from 0.00 to 1.47 and from 0.00 to 1.35, respectively, from April to May. In contrast, from November to February, the aphid population varied from 0.07 to 0.45, while the stink bug population ranged from 0.02 to 0.38. The maximum population of coccinellids was recorded at 3.16 in October 2023. The correlation of pest and predator population with weather parameters showed maximum and minimum temperatures favoured the population development while it was negatively correlated with relative humidity and rainfall. Profiling of root nutrients showed lucerne roots contain a significant amount of essential nutrients that meet the dietary requirements of mice

Standardization of optimum melatonin concentration for drought tolerance at germination and early development stage in rice (CO-54)

Drought stress poses a serious threat to production and nutritional security. In recent years, foliar application of plant growth regulators (PGRs) and nutrients are increasingly employed to overcome physiological constraints resulting in enhanced crop production. Melatonin is a new biomolecule recently found to ameliorate the effect of biotic and abiotic stresses in crop plants. Hence, the present experiment was conducted to assess the optimum concentration of melatonin to mitigate the adverse effect of drought stress on germination and growth components in rice variety CO-54. In this experiment, PEG-mediated drought stress (-0.5 MPa) was imposed with different concentrations of melatonin (at doses of 50, 100, 150, 200, and 250 µM) seed treatments. Together, these results indicated that 200 µM melatonin-treated seeds showed a greater germination percentage (60%), root length (12.23cm), shoot length (8.23cm), fresh and dry weight (0.126g and 0.095g), high vigor index (1910.22), promptness index (64.83), and germination stress index (100) respectively. The result of this experiment provides a shred of strong evidence suggesting that seed treatment of 200 µM melatonin could be considered an effective technique for mitigating the detrimental effects of drought by promoting seed germination and thereby increasing the growth components of seedlings in rice. The study demonstrates that melatonin can shield rice seedlings from the effects of drought stress

Prevalence, characterization and cross infectivity of Rhizoctonia species causing rice sheath blight complex in Tamil Nadu

Sheath blight of rice is a significant biotic stress caused by various Rhizoctonia species, including Rhizoctonia solani (sheath blight), Rhizoctonia oryzae-sativae (aggregate sheath spot) and Rhizoctonia oryzae (sheath spot). The presence of these diverse Rhizoctonia species highlights the complexity of sheath diseases and emphasizes the need for management approaches to mitigate their impact on rice production. In the current study, 37 isolates of Rhizoctonia spp. were collected from various rice-growing regions of Tamil Nadu, India during 2021-22. The isolates were characterized phenotypically and for their virulence pattern. The cultural characteristics including mycelial and sclerotial morphology of the isolates were recorded, aiding in the identification and characterization of the pathogens. An amplicon size of 265 bp was obtained in PCR analysis of R. solani isolates which confirmed their belonging to anastomosis group AG1-IA. Further differentiation using species-specific primers GMRS-3, GMRO-3 and GMROS-2 revealed that 30 isolates belonged to R. solani and 7 to R. oryzae-sativae. The highly virulent isolates of R. solani and R. oryaze-sativae were selected for host range studies in different hosts and the results indicated that all the plant and weed species were found to be infected by both R. solani and  R. oryzae-sativae except pig weed and khaki weed

Exploring gene action and combining ability for yield improve- ment in rice (Oryza sativa L.) landraces

Estimating combining ability is essential for evaluating genotypes and understanding the nature and magnitude of gene actions involved in plant breeding. In a study involving four lines and seven testers, a Line × Tester mating design was employed to analyze combining ability, heterosis, and gene action across 16 yield-related traits. The results indicated significant variances for general combining ability (GCA) and specific combining ability (SCA), underscoring the relevance of additive and non-additive genetic components in trait inheritance. The analysis revealed that the ratio of dominant genetic variance to additive genetic variance was greater than one for most traits, with the exceptions being test weight and the grain length:breadth ratio. This suggests that non-additive gene action predominantly influences the inheritance of the examined traits. Among the parental lines studied, CO 54, CO 55, RL 8601, RL 6298, and RL 27 emerged as the best general combiners for single-plant yield and other traits. Based on the outcomes of standard heterosis, the following hybrid combinations were identified as optimal for augmenting single-plant yield: ADT 58 × RL 2348 (105.33%), CO 55 × RL 6298 (104.5%), CO 54 × RL 6298 (103.87%), CO 54 × RL 8601 (100.76%), ADT 58 × RL 2196 (99.8%), and ADT 56 × RL 6298 (97.65%). These results indicate that the identified cross combinations could be effectively employed in recombination breeding programs focused on producing early-maturing, high-yielding fine-grain rice varieties that align with market requirements

Genetic variability and yield trait associations in F2 populations of traditional rice (Oryza sativa L.) varieties

Analyzing genetic variability and trait correlations is essential for designing effective breeding programs and improving crop characteristics. This study aimed to estimate variability parameters, heritability, genetic advance, skewness, kurtosis, associations, and path coefficients for 13 traits in the F? population derived from the crosses CO 54 × IC 378202 and CO 54 × IC 467496. The cross CO 54 × IC 378202 cross exhibited notable panicle weight with high Genotypic Coefficients of Variation (GCV) (35.94) and Phenotypic Coeffi cients of Variation (PCV) (36.40), elevated Heritability (H2) (97.48), significant Genetic Advance as a Percentage of Mean (GAM) (73.10), and positive skew ness (0.52). Similarly, the CO 54 × IC 467496 cross demonstrated exceptional total tillers per plant, characterized by high Genotypic Coefficients of Varia tion (33.63) and Phenotypic Coefficients of Variation (35.25), substantial Heritability (90.99), notable Genetic Advance as a Percentage of Mean (66.08), and pronounced positive skewness (0.67). In the CO 54 × IC 378202 cross, panicle weight, displayed significant positive correlations (0.641) and direct positive effects (0.2370) on grain yield per plant. Similarly, the CO 54 × IC 467496 cross grains per panicle exhibited strong positive correlations (0.383) and direct effects (0.5360) on grain yield. These findings underscore the significance of panicle weight and grain number per panicle, key deter minants of grain yield, as prime targets for selection in rice breeding pro grams. The observed predominance of additive gene action for these traits suggests their amenability to improvement through pure line selection. By prioritizing these traits, breeders can develop high-yielding rice cultivars, thereby enhancing agricultural productivity and contributing to global food security endeavors

Revolutionizing livestock sustainability: Pioneering breeding strategies for superior forage biomass and quality

Livestock primarily rely on forage crops as a source of feed and nutrition. The milk productivity of a cow or meat production in goat/sheep could directly be associated with the availability of a sufficient quantity of quality green fodders with essential nutrients in a balanced ratio. Feeding the cereal/grass: legume fodders in the required proportion will not only improve productivity but also the reproductive capacity of animals. However, many countries of the world experience a huge gap between demand and availability of green fodder. In this context, emphasis should be placed on developing efficient forage genotypes with increased biomass and quality as per the requirements of animals, duly considering their digestibility. Breeding approaches encompassing required classical approaches, including wide hybridization to exploit natural genetic variability, biotechnological tools such as transgenic technology, marker-assisted selection, genomic selection, and various omics techniques alongside high-throughput phenotyping using multispectral cameras, would help to sustain livestock productivity by meeting out the present and future fodder requirements coupled with enhanced nutrient

Inheritance pattern of Qualitative traits, Genetic analysis and association of yield attributes in F2 populations of Rice (Oryza sativa)

Understanding the extent of genetic variability within the segregating generations is crucial for identifying superior segregants with high yield and better market acceptability. Thus, the present study was carried out to quantify the extent of genetic variation available in the segregating population of rice. Three crosses, viz., CO 55 × IC 457996, CO 55 × IC 464685, and CO 55 × IC 115439 were evaluated using a non-randomized experimental design for six yield attributing and two physical grain quality traits in F2 generation. The inheritance pattern of basal leaf sheath colour and grain colour in CO 55 × IC 115439 indicate digenic complementary gene interaction (9:7), whereas grain colour in CO 55 × IC 464685 exhibits inhibitory gene action (13:3). The positively skewed nature of productive tillers per plant and single-plant yield in the F2 segregants emphasizes the need for intensive selection to facilitate rapid improvement due to the influence of complementary gene action. Moderate to high GCV with high heritability and GAM for traits such as plant height, productive tillers per plant, hundred seed weight, grain width, and single-plant yield in the F2 segregants underscore the prevalence of additive gene action and thus provide the most effective condition for simple phenotypic selection. Moreover, productive tillers per plant and single-plant yield showed a strong positive association in all the crosses. Therefore, productive tillers per plant can be considered an indicator trait when selecting high-yielding segregants for grain yield improvement

Assessing the genetic variability and trait interactions for nitrogen use efficiency in rice

In major cereals, excessive use of nitrogen fertilizers and low nitrogen use efficiency adversely affect land, water and food systems. Developing nitrogen-efficient cereal varieties reduces fertilizer dependence, lowers costs and minimizes environmental pollution while maintaining yield stability. These varieties enhance nitrogen uptake and assimilation, ensuring sustainable food production in low-nitrogen soils. The study aimed to assess the genetic variability for nitrogen use efficiency among 160 rice genotypes by evaluating their performance under three different nitrogen levels -N0 (0N), N50 (50% recommended dose of nitrogen (RDN) and N100 (100% RDN), during rabi season. The physiological and yield traits were recorded at the active tillering and flowering stages. The results indicated that the application of different nitrogen levels significantly affected the physiological traits such as chlorophyll index (SPAD value), leaf greenness index (NDVI), light-adapted PSII quantum yield (Fv'/Fm'), photosynthetic rate at both the stages. Also, there was a significant variation observed in yield traits such as the number of productive tillers, spikelets per panicle, 100-grain weight, spikelet fertility and grain yield among the rice genotypes under different N levels. Correlation analysis showed a significant positive relationship between Fv'/Fm' and photosynthetic rate with grain yield under N50 and N100 levels. Hierarchical clustering analysis identified the five high-yielding genotypes such as IRG91, IRG140, IRG302, IRG374 and IRG375, that performed significantly well under N50 in terms of physiological and yield traits compared to the N0 level and the reduction in yield was significantly less over N100. Future research should focus on identifying the key genes and pathways associated with NUE in rice

Responses of cereals to nitrogen deficiency: Adaptations on morphological, physiological, biochemical, hormonal and genetic basis

Nitrogen (N) is a primary macronutrient essential for plant growth and development. Global nitrogen fertilizer consumption is approximately 120 million tons, with nitrogen use efficiency (NUE) ranging between 25 % and 50 %. Excessive use of nitrogen fertilizer poses significant risks to the envi ronment and living organisms, highlighting the need to reduce fertilizer ap plication, improve NUE, and sustain crop productivity. Sustainable agricul tural practices emphasize minimizing fertilizer usage. Therefore, developing high-NUE crop varieties capable of maintaining yields under reduced nitro gen input is critical for ensuring food security and protecting ecosystem. A promising strategy involves investigating plant responses to varying nitro gen levels, particularly under low-nitrogen conditions. This review explores the morphological, physiological, biochemical, hormonal, and genetic changes in cereals subjected to low-nitrogen conditions. Morphological adaptations include alterations in root and shoot architecture, while physi ological responses involve enhanced chlorophyll content, leaf nitrogen lev els, and photosynthetic efficiency. Biochemical changes are characterized by increased activity of nitrogen uptake and assimilation enzymes, accom panied by hormonal shifts such as elevated auxin levels in roots. These traits provide a foundation for developing nitrogen-efficient crop varieties. Future research should prioritize breeding crops with enhanced tolerance to low-nitrogen conditions to improve NUE, grain quality, and yield potential

Pelletization as a forage conservation technique: Enhancing feed efficiency and sustainability in livestock

Integrating crop and livestock production, especially with cattle, is vital for food security and economic growth in India.  The livestock sector helps increase farm income, boosts the national economy, and provides employment opportunities for millions of people. However, productivity lags global standards due to shortages of quality feeds, including green fodder, dry fodder, and concentrates. Stagnant fodder crop cultivation and dwindling permanent pastures exacerbate the challenge of meeting the rising demand for milk and meat. Addressing these issues is crucial for enhancing livestock productivity and sustaining agriculture. This review highlights the importance of fodder pelletization, compressing animal feeds into dense pellets using a pellet mill. Pelleted feeds offer balanced diets, improved digestibility, and nutrient absorption, with benefits including long-lasting preservation, enhanced handling, stability, bulk density, and palatability. Factors influencing the pelleting process, such as ingredient characteristics, drying, grinding, conditioning, steam pressure, and moisture content, are examined in depth. The positive effects of pelleted feed on ruminant growth and productivity, particularly in cattle and goats, are emphasized, including improvements in milk yield, weight gain, and reproductive performance. These findings emphasize the potential of pelletized feed to address challenges related to fodder scarcity, feed wastage, and transportation costs. This provides valuable insights for efficient diet management in livestock production