Rice cultivation in the Sultanpur district of Uttar Pradesh is increasingly constrained by soil salinization and nutrient depletion, particularly in alkali soils. This study aimed to assess the nutrient status and physicochemical properties of rice-growing alkali soils in the region. A total of 56 geo-referenced soil samples were collected and analyzed for pH, electrical conductivity (EC), organic carbon, available nitrogen (N), phosphorus (P), potassium (K), and sulphur (S). Spatial distribution patterns were evaluated using Inverse Distable Weighting (IWD). Results revealed that all soils were non-saline (EC < 4 dS m-1), highly alkaline, with 42.85% of samples classified as very strongly alkaline (pH > 9.0). Organic carbon levels were low to moderate (0.1-1.4%; mean 0.549%), while available nitrogen ranged from 12.54 to 301.06 kg ha-1 (mean 85.33 kg ha-1), indicating widespread N deficiency. In contrast, phosphorus and potassium were generally in the medium range, and sulphur was found to be medium to high. The low organic matter and nitrogen levels are likely attributed to intensive cropping, imbalanced fertilization, and high temperatures accelerating nutrient loss. These findings underscore the urgent need for site-specific nutrient management strategies to restore soil fertility and sustain rice productivity in the salt-affected landscapes of eastern Uttar Pradesh.
Direct seeded rice (DSR) offers a sustainable alternative to conventional transplanted rice due to its potential to enhance environmental health, improve resource efficiency and suitability for climate resilience. Genetic improvement for direct seeded rice requires identification of genotypes with rapid early vigour, stress resilience and stable yield expression under rainfed conditions. This study focused on dissecting the combining ability and heterosis patterns under direct seeded rainfed conditions. Thirteen lines, three testers and thirty nine F1 hybrids were evaluated using line × tester mating design to identify promising parents and hybrid combinations performing well under DSR systems. Among the parents, lines HPR 2872, HPR 2877, HPR 2888 and tester, HPR 2656 were identified as good general combiners, underscoring their utility as elite donors for enhancing genetic architecture under direct seeded conditions. Among the F1 hybrids, HPR 2872 × HPR 1156, HPR 2873 × HPR 2656, HPR 2875 × HPR 2795, HPR 2902 × HPR 2656 demonstrated outstanding Specific Combining Ability (SCA) effects, heterobeltiosis and standard heterosis, indicating strong role of non-additive genetic control and suitability for heterosis exploitation. By using DSR-adapted genetic material, this study focuses on identifying elite parents and F1 crosses that can accelerate development of climate resilient, resource efficient rice cultivars.
Poor seed germination and weak seedling establishment are major constraints in rice cultivation, often leading to poor plant stands and reduced yield. Seed priming, particularly osmopriming, is an effective technique to improve seed vigor, germination, and early seedling growth, thereby enhancing crop establishment and overall productivity. A field experiment was conducted to evaluate the effect of osmopriming on seed production of rice. The experiment consisted of seven treatments: T1 = distilled water, T2 = 15% polyethylene glycol (PEG 6000) for 24 hours, T3 = 20% PEG 6000 for 24 hours, T4 = 25% PEG 6000 for 24 hours, T5 = 1% KH2PO4 for 6 hours, T6 = 2% KH2PO4 for 6 hours, and T7 = 3% KH2PO4 for 6 hours. Various growth and yield parameters were recorded, including plant height, days to 50% flowering, total number of tillers hill-1, effective tillers hill-1, panicle length, total grains panicle-1, filled grains panicle-1, test weight, and seed yield. The highest number of effective tillers hill-1 (13.36), filled grains panicle-1 (168.66), and seed yield (687.73 g m-²) were observed when seeds were primed with 2% KH2PO4 for 6 hours (T6). Overall, seed priming with 2% KH2PO4 for 6 hours proved to be the most effective treatment for improving growth and seed yield in rice. This technique may be recommended to enhance crop establishment and productivity in rice cultivation.
This study focuses on the characterization of rice genotypes based on their physico-chemical traits, which are critical for determining grain quality and suitability for different end uses. A diverse set of 72 rice genotypes were evaluated for physico-chemical parameters, including amylose content, starch content, gelatinization temperature and gel consistency. The amylose and starch content among the genotypes ranged between 9.52%-29.06% and 64.60%- 92.78% respectively. The gelatinization temperature has shown a narrow range from 66.14°C to 71.74°C. Gel consistency, which indicates the texture of cooked rice, found to be in the range of 33.00 mm to 133.50 mm. The study suggests substantial diversity in the physico-chemical traits among the rice genotypes, which is crucial in selecting promising lines for breeding programs aimed at improving rice quality.
Chromium (Cr6+) is a highly toxic heavy metal that adversely affects plant growth, physiology, and metabolism. This study evaluated the physio-biochemical responses of pot-cultured wheat (Triticum aestivum L. cv. HD-2932) and rice (Oryza sativa L. cv. Lalata) seedlings under varying Cr6+ concentrations, along with the ameliorative effects of chelating agents, diethylenetriaminepentaacetic acid (DTPA) and ethylenediaminetetraacetic acid (EDTA). Chromium exposure significantly reduced shoot and root growth, biomass, and photosynthetic pigments in a concentration-dependent manner, with maximum reductions of 64.3% in wheat and 32.3% in rice at 80 mg L-¹. Chlorophyll and carotenoid contents declined markedly due to oxidative damage and impaired biosynthesis. Biochemically, protein and soluble sugar contents decreased, whereas proline accumulation increased, indicating stress-induced metabolic disruption. Antioxidant enzyme activities, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX), were significantly enhanced, reflecting increased reactive oxygen species (ROS) scavenging. Chelator application alleviated Cr6+ toxicity, with DTPA showing greater efficacy than EDTA. DTPA improved growth, pigment stability, and biochemical attributes, and enhanced antioxidant enzyme activities, particularly in roots. At 20 mg L-¹ Cr6+, DTPA increased wheat shoot length, chlorophyll-a, protein content, and SOD activity compared to untreated controls. Overall, DTPA effectively reduced Cr toxicity and oxidative stress, suggesting its potential role in phytoremediation and improving crop tolerance under chromium-contaminated conditions.
The present study evaluated 40 late-maturing wild rice germplasm lines obtained from the National Research Center on Plant Biotechnology, New Delhi. The germplasm lines were assessed at Banaras Hindu University, Varanasi during the Kharif seasons of 2019 and 2020 to estimate genetic parameters for 12 yield and yield-related traits. Analysis of variance revealed highly significant differences among genotypes for all traits, indicating the presence of considerable genetic variability. The highest genotypic and phenotypic coefficients of variation (GCV and PCV) were observed for total grain yield per plant, followed by panicle weight. Total grain yield per plant exhibited the highest heritability estimate, followed by total grain number per panicle. Genetic advance, expressed as a percentage of the mean, was highest for plant height, while grain number per plant and filled grains also showed relatively high values. Correlation and path coefficient analyses indicated that filled grains per panicle and panicle weight had strong positive effects on grain yield. Therefore, these traits may serve as reliable selection criteria for yield improvement in rice breeding programs. Among the evaluated genotypes, WRG(NKS)-440, WRG(NKS)-434, and WRG(NKS)-421 consistently exhibited superior performance for yield and yield-related traits and may serve as promising parental lines for hybridization aimed at improving grain yield in rice.
Understanding farmers' perceptions and trait preferences is critical for developing rice varieties with high adoption potential. This study adopts an action research approach to evaluate farmer-perceived traits of eight improved rice varieties released within the last decade by Central Rice Research Institute (CRRI), Cuttack, India. Data were collected from 202 farmers (n = 202) across eleven districts in four eastern Indian states - Odisha, West Bengal, Bihar, and Chhattisgarh using household surveys, personal interviews, and focus group discussions conducted after on-farm demonstrations in the farmers' fields. Farmers rated five agronomic traits (tillering capacity, insect and pest resistance, disease resistance, weed competitiveness and lodging resistance) and three market related traits (grain type, cooking quality and marketability) on a 10-point scale. Non-parametric analyses (Kruskal-Wallis H test and Dunn's post hoc test) revealed significant variation in trait perceptions across varieties. CR Dhan 314 was consistently preferred for agronomic performance, while CR Dhan 315 and CR Dhan 510 received the highest ratings for grain type, cooking quality, and marketability. Farmers primarily valued tillering capacity, lodging resistance, and insect-pest resistance in the demonstrated varieties. Demonstration yields were consistent with farmers perceptions of key agronomic traits. The findings indicate that farmers' varietal choices are shaped by a combination of field performance, market potential, and livelihood considerations. Integrating farmer preferences into rice breeding and dissemination strategies following participatory and action research approaches can enhance adoption and impact.
A study was conducted at 20 hybrid combinations derived from Line x Tester (5x4) mating design to estimate the combining ability and heterosis in rice for important yield and its attributing traits. It revealed that there is significant variability present among parents and different cross combinations for majority of the traits studied. The contribution of lines towards the total variance was maximum for days to maturity, panicle length, Specific Leaf Area (SLA) at 80 DAT, Specific Leaf Weight (SLW) at 80 Days After Transplating (DAT) and shoot dry weight. While contribution of testers alone towards the total variance was maximum for Leaf Area Density (LAD) at 60-80 DAT, root dry weight and root shoot ratio. The General Combing Ability (GCA) and Specific Combining Ability (SCA) variances revealed that predominance of both additive and non-additive gene action for different traits and they can be improved either by population improvement methods or by different heterosis breeding methods. JGL 11118 among lines and IR 64 among testers recorded significant GCA effects in desirable direction for majority of the traits. Out of twenty cross combinations studied for heterosis, the crosses viz., BPT 5204 x IR 36 and JGL 11118 x IR 36 and RNR 2465 x IR 64 recorded highest significant positive heterosis for grain yield. Though the perse performance of the parents involved in the heterotic crosses are low, the crosses are heterotic for yield indicating better nicking ability of the parents involved in producing a high heterotic hybrid.
Zinc (Zn) and iron (Fe) are essential micronutrients for rice and play a critical role in improving human nutrition. A laboratory incubation study followed by a pot experiment was conducted during the rabi season of 2019-20 to evaluate the interaction between Zn and Fe in soil and rice plants under submerged conditions. Application of Zn at 10 kg ha-1 significantly increased available Zn in both incubation and pot soils, whereas increasing Fe application reduced Zn availability. Submergence further decreased Zn availability but enhanced Fe concentration in soil. The highest Fe availability was observed in the treatment without Zn but with 10 kg ha-¹ Fe, which was 27.94% higher than the control. A negative correlation between available Zn and Fe in soil was observed across different rice growth stages (r = -0.026 to -0.438*). Increasing Fe levels reduced Zn concentration in rice tissues, while higher Zn application decreased Fe concentration, indicating antagonistic interaction. Grain Zn showed strong positive correlations with root Zn (r = 0.887**) and straw Zn (r = 0.894**). Soil Zn was strongly correlated with plant Zn (R² = 0.80-0.98**), whereas soil Fe showed weak and non-significant relationships. The highest grain Zn (35.88 mg kg-1) was recorded in the treatment receiving 10 kg ha-1 Zn without Fe, while the highest grain Fe (30.5 mg kg-1) was observed with 10 kg ha-¹ Fe without Zn, confirming antagonistic Zn-Fe interactions in the soil-plant system.
Over half of the world's population relies on rice as a staple food, with Asia accounting for about 90% of both its production and consumption, making it central to global food security. Climate warming has increasingly altered the diurnal temperature range (DTR), with night-time temperatures rising faster than day-time temperatures, leading to pronounced diurnal asymmetry. This asymmetric warming shortens rice growth duration, increases spikelet sterility, reduces grain-filling period, and heightens respiratory losses, ultimately lowering grain yield and quality. Over the course of the 20th century, global average surface temperatures rose sharply, with warming rates nearly doubling in the latter half, largely due to anthropogenic activities. Climate data indicate that night-time temperatures are rising more rapidly than day-time temperatures-globally, at 1.4 times the rate, affecting more than half of the Earth's land surface between 1983 and 2017. Night-time heat is particularly harmful for rice; even a 1°C increase above the critical night-time threshold (~24°C) can cut grain yield and biomass by up to 10%. Elevated night-time temperatures during the reproductive stage disrupt respiration, nutrient translocation, and biomass allocation, and degrade grain quality, causing defects like chalky kernels-often more severely than high day-time temperatures. Despite this, yield declines are often attributed solely to night heat, overlooking broader effects of asymmetric warming. Given the variability in temperature patterns across time and regions, there is an urgent need for targeted strategies, such as breeding high-temperature-tolerant rice varieties, reducing heat-induced yield losses, and safeguarding future food security.
Cadmium (Cd) and lead (Pb) are pervasive environmental contaminants that severely affect plant health, productivity, and food safety. This study evaluated the effects of Cd and Pb stress on biomass production, pigment composition, biochemical parameters, antioxidant enzyme activity, and metal accumulation in black gram (Vigna mungo (L.) Hepper, cv. Prasad) and rice (Oryza sativa cv. Khandagiri) seedlings grown under hydroponic conditions, with a focus on the ameliorative effects of selenium (Se). Both metals caused significant reductions in biomass, chlorophyll content, protein levels, and soluble sugars, while enhancing proline accumulation and antioxidant enzyme activities (POX, CAT, and SOD), particularly in root tissues. Selenium supplementation effectively alleviated metal-induced stress by restoring pigment and protein levels, improving sugar content, enhancing antioxidative responses, and reducing Cd and Pb accumulation in shoot tissues. Metal tolerance indices, bioconcentration factor (BCF), total accumulation rate (TAR), tolerance index (Ti), and transportation index (TI)-were significantly improved under Se co-treatment. Comparative analysis revealed that rice exhibited slightly greater physiological resilience and metal handling capacity than black gram. These results highlight selenium's protective potential in alleviating Cd and Pb toxicity through the modulation of antioxidant defense mechanisms and metal homeostasis, offering promising applications for improving crop tolerance and ecological safety in metal-contaminated environment.
During the rainy season of September-October 2022, rice plants (cv. Swarna; MTU7029) in Pedapudi village, East Godavari district, Andhra Pradesh, exhibited brown to black, water-soaked lesions with irregular margins on the outer leaf sheaths near the waterline. The causal fungus was isolated on potato dextrose agar and produced abundant, initially white, round sclerotia that turned brown to black upon maturity. Microscopic examination revealed right-angled branching hyphae with slight constriction at the branch points; hyphal width ranged from 3.04 to 6.68 mm (mean 4.80 mm). Sclerotial diameter ranged from 0.26 to 0.49 mm (mean 0.39 mm). The internal transcribed spacer (ITS) region of the isolate was amplified and sequenced (GenBank accession ON514170), showing 99.83% nucleotide identity with Sclerotium hydrophilum strain SH1 (GenBank accession KX181457.1). Pathogenicity was confirmed on rice cultivar Prabhat (MTU3626) under glasshouse conditions, fulfilling Koch's postulates. Based on cultural, morphological, pathogenic, and molecular characteristics, the pathogen was identified as Sclerotium hydrophilum. According to existing literature, this constitutes the first confirmed report of S. hydrophilum causing stem rot of rice in the Godavari delta zone of Andhra Pradesh.
Nitrogen (N) is a critical macronutrient for rice production, particularly in lowland flooded systems where crop productivity depends heavily on external nitrogen inputs. Global fertilizer-use projections indicate that nitrogen application may reach 130-150 million metric tons annually by 2050, with rice-based systems accounting for a substantial share. In lowland rice, native soil nitrogen is insufficient to meet crop demand, making fertilizer inputs essential for sustaining yields and improving grain nutritional quality. Despite decades of research aimed at enhancing nitrogen use efficiency, effective nitrogen management within the soil-plant-atmosphere continuum remains a major challenge due to inherently high losses of reactive nitrogen under flooded conditions. Processes such as ammonia volatilization, denitrification, and leaching lead to low fertilizer recovery and contribute to environmental and human health impacts, including eutrophication, nitrogen pollution, greenhouse gas emissions, and climate change. This review synthesizes current knowledge on nitrogen loss pathways in lowland rice systems, highlights key methodological challenges and uncertainties in measuring and quantifying reactive nitrogen losses, and examines recent advances in monitoring, modeling, and upscaling approaches. The paper further identifies critical research gaps and discusses implications for mitigation strategies and policy interventions aimed at improving nitrogen use efficiency and promoting the sustainability of lowland rice production.
Field experiments were conducted during the kharif 2020 and rabi 2020-2021 seasons at the Regional Agricultural Research Station, Pattambi, Palakkad, to evaluate the efficacy of diamide and mesoionic insecticide combinations against major insect pests of rice. The treatments included a new combination insecticide, chlorantraniliprole 0.5% + triflumezopyrim 0.45%, applied at 76, 85.5, 95, and 104.5 g a.i. ha-1, along with chlorantraniliprole 0.4% GR @ 40 g a.i. ha-1, triflumezopyrim 10.6% SC @ 25 g a.i. ha-1, and chlorantraniliprole (0.5%) + thiamethoxam (1.0%) GR @ 90 g a.i. ha-1 as standard checks, with an untreated control. Pooled analysis of both seasons revealed that chlorantraniliprole + triflumezopyrim applied at 95 and 104.5 g a.i. ha-1 was most effective in managing yellow stem borer (Scirpophaga incertulas), recording 91.03% and 90.73% reduction in dead heart incidence, respectively, over the control. The same treatments also significantly suppressed leaf folder (Cnaphalocrocis medinalis), with 97.94% and 96.51% reduction in leaf damage. Correspondingly, these treatments resulted in the highest grain yield, with yield increases of 56.00% and 54.14% over the untreated control. The study demonstrates the superior efficacy of the chlorantraniliprole + triflumezopyrim combination for effective pest management and yield enhancement in rice.
Aromatic rice represents a valuable genetic resource, yet comprehensive diversity assessments of non-Basmati landraces from eastern India remain limited. In this study, 36 aromatic rice genotypes-including local landraces, released varieties, and mutants-were evaluated using 32 agro-morphological and quality traits alongside seven SSR markers to assess genetic variability and identify superior genotypes for breeding. Cluster analysis grouped the genotypes into seven distinct clusters, with Cluster I being the largest, while Clusters V, VI, and VII were monogenotypic, reflecting unique genetic backgrounds. Cluster III exhibited the highest intra-cluster variability, and the greatest inter-cluster distance was observed between Clusters VII and V, indicating potential for selecting genetically diverse parents. Cluster mean analysis revealed trait-specific superiority: Cluster II excelled in yield and nutritional traits, Cluster III in grain quality traits, and Cluster VII in both yield and iron content. SSR analysis indicated moderate polymorphism (PIC 0.204 - 0.405), with RM 5474 and RM 72 being highly informative. Unweighted pair group method with arithmetic mean (UPGMA) clustering further confirmed broad genetic diversity, highlighting the value of integrating phenotypic and molecular data for strategic hybridization and the development of improved aromatic rice cultivars.
North-East India is rich in rice landraces cultivated by various tribes for their cultural and agronomic significance. The present study investigated genetic variability and marker-trait associations in 52 North-East Indian rice landraces for yield and yield-related traits. The field experiment was conducted during Kharif 2021 at the Agricultural Research Station (ARS), Bapatla, Acharya N. G. Ranga Agricultural University. Analysis of variance revealed significant differences (P < 0.05) among genotypes for yield traits. Genotyping with 136 SSR markers revealed genetic diversity (GD) ranging from 0.0000 to 0.7301, with an average of 0.4909. The polymorphic information content (PIC) ranged from 0.00 to 0.68, with a mean of 0.42, and the number of alleles per marker varied from 1 to 5, averaging 3.05. Population structure analysis grouped the genotypes into three subpopulations. Marker-trait association analysis identified 11 SSR markers significantly associated with yield traits, explaining 1.75% to 11.93% of phenotypic variation. These results provide valuable insights into the genetic architecture of North-East Indian rice landraces and offer potential molecular markers for use in marker-assisted selection to improve rice yield.
The "Rice Bowl of India," Chhattisgarh, contributes substantially to the country's Non-Basmati rice production, yet remains underrepresented in export markets. This paper examines the growth performance, instability, and trade dynamics of Non-Basmati rice in Chhattisgarh from 2012-13 to 2023-24. The findings indicate a notable increase in production and yield, particularly during 2020-2023. Although the area under cultivation expanded only marginally (CAGR: 1.02%), there were statistically significant increases in production (3.89%) and yield (2.84%). Export performance showed high volatility, with 2023 recording the highest export value (` 2,846.59 million). To translate Chhattisgarh's strong production base into sustainable export gains, targeted policy interventions are required. Strengthening post-harvest handling and milling infrastructure is critical to ensure export-grade quality and reduce losses. Establishing specialized export clusters and logistics hubs in major rice-producing regions can enhance market connectivity. Improving SPS compliance, quality testing facilities, and certification systems will support adherence to international standards. Additionally, capacity building for farmers, FPOs, and millers on export protocols and value addition is essential for enhancing global competitiveness.
Fluoride is naturally present in water, soil, gases, and dust, and elevated concentrations can impose physiological stress on plants. Aluminium (Al³+) toxicity is a major constraint to crop growth, as it disrupts root development, nutrient uptake, and cellular regulatory processes. This study evaluated the effects of varying fluoride ion concentrations (0, 1, 2, 5, 10, 50, and 100 mg L-1), applied alone or in combination with aluminium (Al³+), on rice (Oryza sativa L. cv. Deluxe Ponni). The responses were assessed through changes in the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and glutathione reductase (GR), which were monitored on a monthly basis. Post-harvest analyses determined carbohydrate and protein contents in rice grains and evaluated soil pH, electrical conductivity, and microbial population. Fluoride-aluminium stress enhanced antioxidant enzyme activities, indicating the activation of defense mechanisms to mitigate oxidative damage. Fluoride alone increased soil pH by reducing acidity, whereas combined fluoride-aluminium treatments resulted in a moderate pH increase, likely due to aluminium hydroxide formation and associated proton dynamics. This slight increase in soil pH promoted microbial activity, and overall, the combined fluoride-aluminium treatment elicited favorable physiological responses in rice and improved soil quality.
A battery-assisted single-row weeder was developed and evaluated in comparison with a conventional manually operated cono-weeder for wetland rice cultivation. The developed weeder consists of a frame, DC motor, battery pack, transmission system, controller, cutting unit, handle, and support wheel. Power from the battery-operated DC motor is transmitted to the cutting unit through a chain-sprocket mechanism, while a controller regulates uniform power supply and operational speed. Three cutting units-J-type, L-type, and cage wheel type-were evaluated at a row spacing of 20 cm. Performance parameters such as field capacity, field efficiency, weeding efficiency, plant damage, labour requirement, cost economics, and energy consumption were assessed. Results indicated that the battery-assisted weeder achieved an actual field capacity of 0.03 ha h-1, which was more than twice that of the manually operated cono-weeder. It also recorded higher field efficiency (85%), lower plant damage (1.94%), and reduced labour requirement (34 man-h ha-1). The cost of operation was Rs. 4108 ha-1, which was lower than that of the cono-weeder (Rs. 4712 ha-1). Overall, the battery-assisted weeder significantly reduced labour drudgery and operational time while lowering weeding costs, indicating its potential as an efficient mechanized weeding option for small and medium-scale rice farmers.
The escalating cost of conventional feed ingredients has intensified the demand for alternative, cost-effective, and sustainable inputs in aquaculture nutrition. Rice byproducts, including rice bran, rice polish, broken rice, and de-oiled rice bran, offer considerable potential owing to their abundance, nutrient density, and low market price. This study investigates the optimization of rice-byproduct-based feed formulations for Indian major carps using linear programming (LP) modelling. Rice byproducts, considered waste, were evaluated as cost-effective and nutrient-rich alternatives to conventional aquafeed ingredients. Proximate composition data were incorporated into a linear programming framework to formulate 100 kg of feed using these ingredients, in order to determine optimal combinations that minimize production costs while fulfilling species-specific nutritional requirements for growth and health. Results indicated that for a 100 kg feed formulation, protein contents of 22.17%, 21.32%, and 20.45% could be obtained from the mixture, costing approximately Rs 1693.70, Rs 1704.95, and Rs 1670.95, respectively. This indicates that the formulation will cost less than Rs 20 per kg of feed, without compromising the nutrient content required for the growth of fish at different stages. This will help increase the productivity and profitability of fish farming.
