BRRI Dhan29 Research Articles

Energy potential of biomass from rice husks in bangladesh: An experimental study for thermochemical and physical characterization

Rice husks, abundant leftovers from rice production, offer immense potential as a renewable energy source through thermochemical conversion processes. However, their efficient utilization hinges on understanding their unique thermal properties and reaction kinetics. This study addresses a critical gap by meticulously analyzing four prominent Bangladeshi rice husk varieties: BR22, BRRI Dhan46, BRRI Dhan47, and BRRI Dhan49. Through rigorous experimentation, we unveil a comprehensive dataset encompassing their physical, chemical, and thermochemical characteristics. Our investigation reveals favorable alignment of moisture content with various conversion technologies, alongside suitable bulk density for efficient handling. Proximate analysis sheds light on crucial components like ash, volatile matter, and fixed carbon, vital for optimizing combustion efficiency. Furthermore, elemental analysis not only highlights the presence of ash-forming elements but also assures low nitrogen and sulfur content, suggesting potential environmental benefits compared to conventional fuels. Delving into thermochemical characteristics, we measured higher heating values ranging from 13.31 MJ/kg to 14.42 MJ/kg, confirming the viability of these rice husk varieties for energy conversion. Thermogravimetric and kinetic analyses further illuminate their unique decomposition behavior, with BRRI Dhan47 exhibiting the highest decomposition rate, emphasizing the distinct reactivity profiles of different varieties. This extensive dataset empowers researchers and industry professionals with valuable insights for informed decision-making. By understanding the unique attributes of each rice husk variety and their behavior during conversion, we can optimize operational parameters for various thermochemical methods. Ultimately, this study bridges a critical research gap and paves the way for more efficient and sustainable utilization of rice husks as a renewable energy source, contributing to a greener future.

Assessment of phenotypic and genotypic diversity in rice for salinity tolerance at reproductive stage

Soil salinity has turned out to be an important global concern, which affects tenable rice production in many agricultural countries like Bangladesh. A cross was made between Binadhan-7 with FL-478 for developing salt tolerant advance lines to assess phenotypic and genotypic diversity in rice for salinity tolerance. Twenty advance rice lines (Binadhan-7/FL-478) along with check varieties were screened for salinity tolerance at reproductive stage using sea site saline water having electrical conductivity (EC) 10 dS m-1. Among the twenty rice lines, seven lines were tolerant, three were moderately tolerant, six were susceptible, four were highly susceptible on the basis of phenotypic evaluation. Seven simple sequence repeat (SSR) markers linked with salt tolerance quantitative trait loci were used for investigation of salt tolerant rice lines. The result revealed that an average number of 6.286 alleles per locus were detected, with polymorphism information content (PIC) values ranging from 0.672 (RM490) to 0.838 (RM562). The highest gene diversity value (0.812) was found in RM562 and the lowest (0.684) was in RM490. A dendrogram constructed from the genetic distance of the genotypes produced four distinct clusters of twenty rice genotypes. Considering both phenotypic and genotypic observation, seven genotypes viz., Binadhan-10, FL-478, SL-51, SL-56, SL-77, EFSD-59 and IZSD-45 were identified as salt-tolerant; on the other hand, EFSD-21, SL-28, SL-32, SL-10, BRRI dhan28, and Binadhan-7 were identified as salt-susceptible. The identified salt-tolerant rice genotypes could be used in the improvement of rice breeding programs. Bangladesh J. Nuclear Agric, 37(2): 1-18, 2023

Evaluation of two advanced generation boro rice mutants based on morpho-physiological criteria

Experiments were performed at farmers’ fields of five locations viz., Mymensingh, Sherpur, Jamalpur, Natore and Naogaon districts with two promising Boro rice mutants, RM-16(N)-8, RM-16(N)-10 and a check, BRRI dhan58 to evaluate some morpho-physiological features and its impact on grain yield. The experiment was setup in RCB design with three replications. Results revealed that high yielding genotypes, in general, showed superiority in morpho-physiological characters (leaf area, leaf area index, total dry mass production, absolute growth rate, relative growth rate, chlorophyll, total sugar and soluble protein content in leaves and harvest index) than the low yielding one. Results further indicated that genotype improvement efforts have achieved higher grain yield by higher growth rate at early growth stages and better assimilate partitioning to economic yield and short stature plants are unlikely to improve harvest index and resistant to lodging in rice. The mutant, RM-16(N)-10 had medium plant stature with greater biomass production capacity, superiority in growth and biochemical parameters and improve dry matter partitioning to economic yield which resulted higher number of grains panicle-1, thereby grain yield. In contrast, RM-16(N)-8 showed inferiority in morpho-physiological characters and performed the lowest yield attributes and grain yield. This information may be used in future plant breeding programme. Bangladesh J. Nuclear Agric, 37(2): 69-80, 2023

Yield Performance of Binadhan-24 Over Two Selected Locations in Bangladesh

Boro is the most important cereal crops in terms of production to the farmers in Bangladesh. An experiment was conducted to examine the suitability and productivity of two rice varieties cultivating in Boro season. The experiment was consisted of Binadhan-24 and BRRI dhan58 and it was conducted at the farmer’s field of Mymensingh and Kishoreganj districts from December, 2022 to May, 2023. The experiment was performed in Randomized Complete Block Design (RCBD) with three replications. Higher yield (7.03 tha-1) was recorded in Binadhan-24 compared to the variety BRRI dhan58 (6.53 tha-1). A higher day to maturity was found in BRRI dhan58 (152.50 days) compared to the varieties Binadhan-24. The highest effective tiller hill-1 (24.90) and number of filled grain panicle-1 (142) were recorded in Binadhan-24 where in BRRI dhan58, effective tiller hill-1 and number of filled grain panicle-1 were 22.19 and 136.80 respectively. Higher 1000 seed wt. (24.38 g) was found in Binadhan-24 compared to another variety. And the maximum yield potential (7.03 tha-1) was recorded in Binadhan-24. This experiment will be useful to select Boro genotypes with high yield potential and future breeding stock in area specific suitable locations and all over the world.

YIELD PERFORMANCE AND COST-EFFECTIVENESS OF DRY DIRECT SEEDED BORO RICE IN RESPONSE TO SOWING DATE AND IRRIGATION REGIME

Dry direct seeding is a new technology to address the water scarcity problem faced in rice culture in boro season. An experiment was run at Bangladesh Agricultural University in Mymensingh, to determine the impact of the sowing date and irrigation schedule on the yield potential and cost effectiveness of boro rice grown under a dry direct seeding system. The experiment was laid out in a split-plot design and consisted of two sowing dates viz. 10 February and 02 March; and five irrigation regimes viz., no irrigation, one irrigation at 25% field capacity (FC), two irrigations (at 25% FC and at 1 week after 25% FC), three irrigations (at 25% FC, at 1 and at 2 weeks after 25% FC) and four irrigations (at 25% FC, 1, 2 and 3 weeks after 25% FC) replicated thrice assigning sowing date in main plots and irrigation in sub-plots. The result showed that BRRI dhan58 sown on 10 February with four irrigations (at 25% FC, 1, 2 and 3 weeks after 25% FC) produced the highest grain yield and economic return which was statistically comparable to those for two (at 25% FC and at 1 week after 25% FC), and three irrigations (at 25% FC, at 1 and at 2 weeks after 25% FC). The present study concludes that rice variety BRRI dhan58 can be cultivated successfully to achieve maximum yield and economic return by sowing the seed during 10 February to 02 March and applying 2 - 3 irrigations at the vegetative phase in dry direct seeding system.

Development of Submergence Tolerant Rice Variety BRRI dhan79 for Flash Flood Ecosystem of Bangladesh

Tolerance to submergence stress is an important breeding objective for the areas where rice cultivars are subjected to complete inundation for a week or more. Submergence tolerance is an important trait for rice (Oryza sativa L.) in the flash flood-prone ecosystem. The trait is largely controlled by a major gene designated as Sub1 located on chromosome 9. Submergence of rice (Oryza sativa) by flash flooding is a major constraint to rice production in Bangladesh. Quantitative trait loci analyses have revealed that a large portion of this variation in submergence tolerance can be explained by Sub1. A newly released submergence tolerant rice variety namely BRRI dhan79 was developed by hybridization between BRRI dhan49*6/BRRI dhan52 through Marker Assisted Backcrossing and selection method where BRRI dhan52 (submergence tolerant mega variety in Bangladesh) used as Sub1 donor. It can tolerate upto three weeks complete submergence at vegetative stage whereas Sub1 donor mega variety BRRI dhan52 can tolerate on an average two weeks complete submergence condition. It can also tolerate 50-60 cm water stagnation for 15-20 days after de-submergence. The variety has satisfactorily been passed in the proposed variety trial conducted in flash flood prone farmers' field in Bangladesh. As a result, the National Seed Board (NSB) of Bangladesh approved this rice variety for commercial cultivation for the flash flood affected rainfed lowland ecosystem (Transplanted Aman season) in 2017. It meet up all the trait of modern plant likely medium plant heihght (112 cm), strong and stature culm structure, erect flag leaf with stay green leaf at maturity stage and high yield potential with 140 days growth duration (in case of three weeks submergence mature by 160 days). It can produce 5.5 t/ha grain yield under non-stress condition and 4.0-4.5 t/ha yield under three weeks submergence condition. The grain shape of the variety is medium bold. The rice production scenario in flash flood affected region of Bangladesh has been remarkably improved after releasing this rice variety. It has not only change the socio-economic status of farmers but also sustaining food security.

Growth Performance of Rice Genotypes at the Seedling Stage under Different Salinity Stresses

Background: Worldwide coastal rice growing areas are severely affected by salinity which has become a major constraint to rice production. Salinity is a serious soil problem in rice-growing countries, severely limiting global rice production. Methods: In this study, the seedlings of 21 rice genotypes were tested against seven different levels of salinity concentrations (0.3, 2, 4, 6, 8, 10 and 12 dSm-1) under a hydroponic system in a glasshouse condition at Field 10, Faculty of Agriculture, Universiti Putra Malaysia (UPM). Data on seedling growth and salinity injury of the tested rice genotypes were recorded. Result: The results showed that Pokkali, FL478 and Binadhan-10 were tolerant at 12 dSm-1; BRRI dhan73, BRRI dhan61, Binadhan-8, BRRI dhan67 and BRRI dhan47 were tolerant at 10 dSm-1; Putra-1 were moderately tolerant at 8 dSm-1 and MR263, MR284, MR211 and MRQ74 were tolerant at 4 dSm-1 and rest of the genotypes were salt susceptible. The lower amount of Na: K and Na: Ca were measured from rice genotypes, Pokkali and FL478 at maximum salinity levels. The promising rice genotypes that were tolerant at 12 dSm-1 would be taken into consideration for a hybridization program to develop a new salt-tolerant rice variety.

AGRO-MORPHOLOGICAL CHARACTERIZATION AND GENETIC DIVERSITY ASSESSMENT OF NINETEEN BRRI-RELEASED RICE VARIETIES

Knowledge on genetically determined several growth parameters including morpho- physiological and developmental parameters are essential for rice breeding programs. Genetic divergence helps in the development of superior recombinants, which is prerequisite in any crop improvement program. The aim of the present study was to characterize 19 rice varieties based on agro-morphological descriptors and genetic diversity. The experiment was conducted at Bangladesh Rice Research Institute farm, Gopalganj, using a randomized complete block design with three replications. Both the qualitative and quantitative agro-morphological traits were diversified. The observed variations in the qualitative data were primarily accounted for by the blade pubescence, anthocyanin color of the leaf sheath, lemma-palea color, grain tip color, and awning. The top five axes of PCA contributed 81.04% of the total variation. The varieties were divided into five groups based on the cluster. With six genotypes, Cluster IV was the largest group, whereas Cluster I was the lowest with just one genotype. Cluster IV had the greatest intra-cluster distance, whereas clusters IV and I had the greatest inter-cluster distances. Contrarily, cluster IV had the highest cluster means for most of the quantitative characteristics noticed. Once more, grain length was the trait that contributed most to divergence. While considering results from genetic distance, the varieties under cluster IV (BRRI dhan29, BRRI dhan89, BRRI dhan92 BRRI dhan97, BRRI hybrid dhan3, BRRI hybrid dhan5) might be selected for additional breeding after taking the results of the genetic distance into consideration.

Growth and Yield of Transplant Aman Rice (BRRI dhan38) as Affected by Weeding and Zinc Level

Growth and Yield of Transplant Aman Rice (BRRI dhan38) as Affected by Weeding and Zinc Level

REDUCTION OF CHEMICAL FERTILIZER APPLICATION BY USING BIOCHAR FOR THE GROWTH AND YIELD OF RICE CV. BRRI dhan 29

A field experiment was carried out at research field, Hajee Mohammad Danesh Science and Technology University, Dinajpur to assess the reduction of chemical fertilizer application by using biochar for the growth and yield of rice cv. BRRI dhan 29. The experiment was performed with five treatments viz. T1 = Recommended doses of N, P, K and S, T2 = Biochar 10 t ha-1, T3 = Biochar 7.5 t ha-1 + half recommended doses of N, P, K and S, T4 = Biochar 5 t ha-1 + half recommended doses of N, P, K and S and T5 = Biochar 2.5 t ha-1 + half recommended doses of N, P, K and S. The experiment was laid out in Randomized Complete Block Design (RCBD) with four replications. The highest plant height (102.35 cm) and the number of tillers hill-1 (26.35) was found in the treatment T1 which was statistically similar to the treatment T3 with the values 99.93 cm and 25.89, respectively. The panicle length (25.01 cm), number of spikelets hill-1 (14.30), number of grains panicle-1 (194.50) and 1000-grain weight (25.03 g) were found maximum in the treatment T3 which was statistically similar to the treatment T1 with the values 24.89 cm, 13.87, 193.50 and 24.37 g; respectively. The highest grain yield (7.46 t ha-1) and straw yield (9.92 t ha-1) was found on T1 treatment which was statistically similar to the treatments T3 (7.42 and 9.86 t ha-1). The highest biological yield (17.28 t ha-1) was measured in the treatment T3. These results suggest that application of 7.5 t ha-1 biochar with half recommended doses of N, P, K and S may reduce 50% of N, P, K and S for rice cultivation (cv. BRRI dhan 29) as these treatments acquire statistically similar production to solely chemical fertilizer applications. However, further research is needed on biochar production, cost efficiency for biochar application and environmental aspects of biochar application.

Evaluation of Some HYV Boro Rice Varieties for Drought Tolerance Based on Morpho-Biochemical Traits

An experiment was conducted to study the drought tolerance in selected boro rice varieties in pots at the Farm Research Laboratory of Dept. Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh in Rabi season of 2014-2015. In this experiment, drought was induced by manipulating the field capacity (30-35% FC as drought, 95-100% FC as control) and moisture content of the soil in the pot. Drought treatment was started 36 days after transplanting and continued till harvest. The work was comprised based on several morphological and biochemical approaches viz. days to 50% flowering, plant height, panicle length, no of total tillers hill-1, no of effective tiller hill-1, days to maturity, no of filled grains panicle-1, no of unfilled grains panicle-1, grain panicle-1, 100 seed weight, grain yield panicle-1, yield hill-1, spikelet fertility, proline and L-ascorbic acid were found to be changed significantly in drought stress as compared to the control. In drought conditions, the highest yield performance was showed in BRRI dhan29 by changing 33.11% compared to its control. Due to drought induction proline accumulation was significantly upregulated by 2.53 and 2.10 folds in BRRI dhan36 and BINA dhan5, respectively and L-ascorbic acid was decreased lowest in BINA dhan10, BRRI dhan50, and BRRI dhan29 by 27.29%, 41.31%, and 43.91%, respectively. This study produced substantial information about the drought tolerance status of the selected boro rice varieties, and therefore, can be an aid for any future attempt to improve the drought tolerance of the studied varieties. Vol. 10, No. 3, December 2023: 247-258

Comprehensive Assessment of the Genotype-Environment Interaction and Yield Stability of Boro Rice Genotypes under Four Environments in Bangladesh Using AMMI Analysis.

Yield stability, alongside high yield potential and broad adaptation to various agroclimatic environments, is a key objective for rice breeders aiming to ensure food security. This study aimed to explore the most suitable and stable Boro rice genotypes for Bangladesh. Ten Boro rice genotypes underwent testing in four environments during the 2022 Boro season to investigate genotype-environment interaction (GEI) and yield stability performance. The experiment utilized three replications of a completely randomized block design. Yield stability performance was assessed through combined analysis and the additive main effects and multiplicative interaction (AMMI) model. The combined ANOVA revealed that the environment explained 10.23%, while GEI accounted for 9.17%, and the genotypes captured 80.60% of the variance, significantly impacting grain yield. Significance was observed in the environment, genotype main effects, and GEI. Analysis indicated that BRRI dhan 68 yielded the highest (6,754 kg·ha-1) and BRRI dhan 88 the lowest (5,620 kg·ha-1) among the investigated genotypes. In addition, genotypes BRRI dhan 84, BRRI dhan 81, and BRRI dhan 67 exhibited the highest grain yields. The Rangpur environment demonstrated considerable stability across the four environments with a high mean value of grain yield (7,206 kg·ha-1). Therefore, the AMMI model emerges as a valuable tool for identifying the most suitable and stable Boro rice genotypes with high-yielding potential across various regions in Bangladesh, as well as under diverse conditions.

Enhancing Transplant Aman Rice Productivity through NPK Fertilizer Split Application Scheduling Under Zero Till Non-Puddled Condition

This experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to evaluate the varietal response of split application of NPK fertilizer application schedule on transplant aman rice under zero till non-puddled condition. The experiment comprised three rice varieties viz. Bashiraj (local), BRRI dhan49 (inbred), Dhanigold (hybrid); and seven NPK fertilizer application schedules. The experiment was laid out in a randomized complete block design with three replications. The effect of variety, NPK fertilizer split application schedule and their interaction showed significant variation on the yield attributes and yield of aman rice. In interaction, the highest number of effective tillers hill-1 (11.66), total spikelets panicle-1 (164.00), grains panicle-1 (151.22), 1000-grain weight (38.70 g), grain yield (5.67 t ha-1) and harvest index (60.36%) were obtained from hybrid variety Dhanigold when fertilized following 3-splits of N [1/3 at 14 days after transplanting (DAT) + 1/3 at maximum tillering (MT)+ 1/3 at panicle initiation (PI)] and P (1/3 as basal + 1/3 at MT + 1/3 at PI ), and single split of K as basal (full dose). Same treatment combination also provides the highest yield of BRRI dhan49, but the local Bashiraj gave the highest yield at recommended practice where only N was top-dressed at 3 splits. Based on this result, it may be concluded that for better productivity hybrid Dhanigold and inbred BRRI dhan49 might be fertilized with 3-splits of N (1/3 at 14 DAT + 1/3 at MT + 1/3 at PI) and P (1/3 as basal + 1/3 at MT + 1/3 at PI) and full dose of K as basal during aman season under zero till non-puddled condition. On the other hand, for local variety Bashiraj 3-spilts of N either [½ as basal + ¼ at active tillering (AT) + ¼ at PI] or N (1/3 at 7 DAT + 1/3 at MT + 1/3 at PI) and P, K as single split as basal appeared as the best application schedule.

Enhancing Productivity of Aromatic Winter rice through Boron Management

Boron (B) is one of the most important micronutrients for plants which play vital role in various metabolic process. Boron deficiency in rice has been widely reported in many rice growing regions of the world including Bangladesh. Therefore, a field experiment was carried out at the Agronomy Field Laboratory of Bangladesh Agricultural University, Bangladesh during the period from November 2022 to May 2023 to study the effect of different levels of B on aromatic Boro rice (cv. BRRI dhan50. The experiment comprised ten treatments viz. control (0 kg B ha-1), 2.0 kg B ha-1 (basal), 4.0 kg B ha-1 (basal), 6.0 kg B ha-1 (basal), 1.0 kg B ha-1 (basal) + 1.0 kg B ha-1 (soil application at 30 DAT), 2.0 kg B ha-1 (basal) + 2.0 kg B ha-1 (soil application at 30 DAT), 3.0 kg B ha-1 (basal) + 3.0 kg B ha-1 (soil application at 30 DAT), 1.0 kg B ha-1 (basal) + 0.5 kg B ha-1 (soil application at 30 DAT) + 0.5 kg B ha-1 (foliar application at flag leaf stage), 2.0 kg B ha-1 (basal) + 1.0 kg B ha-1 (soil application at 30 DAT) + 1.0 kg B ha-1 (foliar application at flag leaf stage) and 3.0 kg B ha-1 (basal) + 1.5 kg B ha-1 (soil application at 30 DAT) + 1.5 kg B ha-1 (foliar application at flag leaf stage). The experiment was laid out in Randomized Complete Block Design with three replications. The yield and yield contributing characters were influenced significantly by different levels of B. The highest number of total tillers hill-1 (14.65), effective tillers hill-1 (12.75) and grains panicle-1 (106.66) were obtained from 1.0 kg B ha-1 (basal) + 0.5 kg B ha-1 (soil application at 30 DAT) + 0.5 kg B ha-1 (foliar application at flag leaf stage). The highest grain (5.38 t ha-1) and straw (6.27 t ha-1) yields were also obtained from the same treatment which was at par with the treatment 2.0 kg B ha-1 (basal) + 1.0 kg B ha-1 (soil application at 30 DAT) + 1.0 kg B ha-1 (foliar application at flag leaf stage) (T8) whereas the lowest values were found in control. Results indicated that 1.0 kg B ha-1 (basal) + 0.5 kg B ha-1 (soil application at 30 DAT) + 0.5 kg B ha-1 (foliar application at flag leaf stage) appears as the promising practice in terms of grain yield of aromatic Boro rice (cv. BRRI dhan50).

Genotype Selection from Azide‐Induced Rice Mutants Using Multitrait Genotype–Ideotype Distance Index (MGIDI): Unveiling Promising Variants for Yield Improvement

Development of high‐yielding rice (Oryza sativa L.) is a crucial need for succeeding food security that needs the presence of great genetic variability to be used in breeding programs. Creating new variants through sodium azide mutagenesis can be a better alternative in advancing plant breeding issues. The generation and characterization of mutants represent an effective method for choosing genotypes with desired attributes. In this study, we focused on inducing mutations in the genetic base of a mega rice variety (BRRI dhan28) using sodium azide, evaluating the genetic diversity of the mutants, and identifying promising genotypes among the mutants using quantitative trait analysis and genetic criteria. The mutants exhibited substantial variation, as evidenced by descriptive statistics and analysis of variance. The estimated heritability and genetic advance indicated that nearly all traits had a high level of heritability and followed a complex pattern of inheritance. The strong correlations observed between grain yield and flag leaf length, branch panicle−1, grain panicle−1, 100‐grain weight, straw yield hill−1, and harvest index indicate that prioritizing these traits during selection could substantially improve other desirable characteristics. Additionally, we employed the principal component analysis which revealed that the first two components collectively accounted for 32.16% of the total variation, providing essential information about the genetic relatedness of the mutants. The Multitrait Genotype–Ideotype Distance Index (MGIDI) analysis revealed that out of 100 mutants, only eight exhibited noteworthy performance. These findings provide insights into the efficiency of azide in creating genetic variations in rice traits and offer valuable resources for future breeding programs aimed at developing high‐performing rice varieties.

Integrated effect of manures and fertilizers with the allelopathy of Fimbristylis dichotoma (L.) on the yield performance of rice

Allelopathy plays an important role in weed control and crop productivity. In light of these, an experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh under the Old Brahmaputra Floodplain (AEZ-9) during the period from July 2021-June, 2022 to assess the combined effect of Fimbristylis dichotoma residues with manures and fertilizers on rice yield performance in boro season. The experiment consisted two rice varieties viz., BRRI dhan29 and BRRI dhan89; and six treatments of the combination of residues with manures and fertilizers viz., Control; Residues @ 3 t ha-1 + Recommended doses of inorganic fertilizers; Residues @ 3 t ha-1 + Tricho-compost @5 t ha-1; Residues @ 3 t ha-1 + Tricho-compost @1.5 t ha-1 + 25% less than recommended doses of inorganic fertilizers; Residues @ 3 t ha-1 + Tricho-compost @2.5 t ha-1 + 50% less than recommended doses of inorganic fertilizers; Residues @ 3 t ha-1 + Tricho-compost @3.75 t ha-1 + 75% less than recommended doses of inorganic fertilizers. The experiment was laid out in a randomized complete block design (RCBD) with three replications. The highest grain yield was produced in T4 (Residues 3 t ha-1 +Trichocompost @1.5 t ha-1 + 25% less than recommended fertilizers treatment). From the above results it was found that the variety BRRI dhan29 and T4 (Residues 3 t ha-1 +Trichocompost @1.5 t ha-1 + 25% less than recommended fertilizers treatment) treatment exhibited the superior effect. The current study's findings indicate that the combination of manures and fertilizers increases yield and yield-contributing characteristics, and that Fimbristylis dichotoma residues have an herbicidal impact for inhibiting weed growth.

Enhancing rice growth and yield with weed endophytic bacteria Alcaligenes faecalis and Metabacillus indicus under reduced chemical fertilization.

Endophytic bacteria, recognized as eco-friendly biofertilizers, have demonstrated the potential to enhance crop growth and yield. While the plant growth-promoting effects of endophytic bacteria have been extensively studied, the impact of weed endophytes remains less explored. In this study, we aimed to isolate endophytic bacteria from native weeds and assess their plant growth-promoting abilities in rice under varying chemical fertilization. The evaluation encompassed measurements of mineral phosphate and potash solubilization, as well as indole-3-acetic acid (IAA) production activity by the selected isolates. Two promising strains, tentatively identified as Alcaligenes faecalis (BTCP01) from Eleusine indica (Goose grass) and Metabacillus indicus (BTDR03) from Cynodon dactylon (Bermuda grass) based on 16S rRNA gene phylogeny, exhibited noteworthy phosphate and potassium solubilization activity, respectively. BTCP01 demonstrated superior phosphate solubilizing activity, while BTDR03 exhibited the highest potassium (K) solubilizing activity. Both isolates synthesized IAA in the presence of L-tryptophan, with the detection of nifH and ipdC genes in their genomes. Application of isolates BTCP01 and BTDR03 through root dipping and spraying at the flowering stage significantly enhanced the agronomic performance of rice variety CV. BRRI dhan29. Notably, combining both strains with 50% of recommended N, P, and K fertilizer doses led to a substantial increase in rice grain yields compared to control plants receiving 100% of recommended doses. Taken together, our results indicate that weed endophytic bacterial strains BTCP01 and BTDR03 hold promise as biofertilizers, potentially reducing the dependency on chemical fertilizers by up to 50%, thereby fostering sustainable rice production.

Marker-Assisted Breeding for Enhancing Stress Tolerance in Rice (Oryza sativa L.): A Review

Rice productivity faces significant challenges from climate change and sudden outbreaks of pests and diseases. Conventional breeding alone struggles to produce stress-resistant varieties, making marker-assisted breeding (MAB) a valuable complement. MAB enhances conventional breeding by employing molecular markers tightly linked to target genes, increasing efficiency without entirely replacing traditional methods. This review evaluates gene introgression effects and the role of MAB in improving rice productivity based on secondary data sources. Notable gene targets include Xa4, Xa5, Xa13, Xa21 and Xa27 for bacterial blight; Pi2, Pi5, Pi9 and QTLs on chromosomes 1, 2, 11 and 12 for blast resistance; Gm1 and Gm4 for gall midge; Saltol for salinity tolerance; qDTY1.1, qDTY2.1 and qDTY3.1 for drought tolerance; Sub1A for submergence; and yld1.1, yld2.1 and GW6 for yield enhancement. Introgressing these genes has led to the development of resilient rice lines capable of thriving under biotic and abiotic stresses, with notable increases in yield over susceptible recurrent parents. For instance, the introgression line DHA-10 (5.68 t/ha) yields more than its parent BPT5204 (4.97 t/ha), while the submergence-tolerant BR9157-12- 2-37-13-17 produces 3.44 t/ha, outperforming BRRI dhan33 (1.73 t/ha). These cases illustrate the transformative impact of MAB in developing highyielding, resilient rice varieties, underscoring its invaluable role in enhancing rice productivity under diverse stress conditions

Evaluation of effectiveness of foliar application of urea fertilizer on growth, development and yield of BRRI Dhan 84 in barind tract, Bangladesh

As a component of enzymes, hormones, amino acids, nucleic acids, nucleotides, and chlorophyll, nitrogen is a vitally important nutrient for plants. It encourages quick plant growth and enhances grain quality and production through increased protein synthesis, tillering, leaf area development, grain formation and filling. Urea is one of the greatest and popular sources of nitrogen. Rice production is hampered when nitrogen fertilizer, particularly urea, is unavailable during crucial times (flood, sowing season, drought). Studies in different literature have shown that applying nitrogen fertilizer as foliar application in addition to the soil application increases its efficiency. A study was carried out to observe the theme “Evaluation of effectiveness of foliar application of urea fertilizer on growth, development and yield of BRRI Dhan 84 in Rajshahi region’’ in the field of Agronomy and Agricultural extension Department Field, University of Rajshahi, Bangladesh from December 2023-April 2024. Six different percentage of urea as foliar application with BRRI Dhan-84 rice variety were used for this study. 1. T1= N0% Control, 2. T2= 65% of recommended dose (N 50% as SA + 15% as FA), 3. T3= 70% of recommended dose (N50% as SA + 20% as FA), 4. T4= 75% of recommended dose (N50 % as SA + 25 % as FA), 5. T5= 80% of recommended dose (N60% as SA + 20% as FA), 6. T6= N100% Soil application (Traditional practice). A randomized complete block design with three replications was applied in this study. Almost all the parameters under this study showed significant results of foliar application of urea. Treatment T4 showed the highest result of phenological and growth parameters than the traditional practice and T1 (control) the lowest. Foliar fertilizer improves crop quality, regulate nutrient deficiencies. It is a fertilizer saving and an economical technique than others. This study adds to the body of knowledge by providing actual data on the dynamics of rice production's profitability, productivity and fertilizer saving.

Molecular Diversity Analysis of Some Selected Brri Developed Rice Varieties Using Ssr Markers

Molecular characterization of 26 modern rice varieties of Bangladesh was performed using 52 simple sequence repeat markers (SSRs) to estimate the genetic diversity and to reveal genetic relationships among rice cultivars. A total of 156 alleles were detected where the number of alleles per locus generated by each marker varied from 2 to 7, with an average of 3. The band size for a given microsatellite locus ranged from 79 to 278 bp. The polymorphism information content (PIC) for the SSR loci ranged from 0.08 to 0.79, with an average of 0.35. RM566 was the best marker for identification and variability assessment of varieties as revealed by PIC values. A UPGMA dendrogram generated using the NTSYS-pc revealed four clusters with a similarity coefficient of 0.55, whereas phylogenetic cluster analysis of the SSR data based on Nei-genetic distance divided the varieties into three groups. Two- and three-dimensional graphical views of principal coordinate analysis showed the spatial distribution of the varieties and revealed that BRRI dhan56, BRRI dhan51, BRRI dhan52, BRRI dhan61, BRRI dhan62 and BRRI dhan66 were found far away from the centroid of the cluster. The findings of this study are helpful for varietal identification, background selection during backcross breeding and for selecting the suitable genetically diverse parents for crossing programs. SAARC J. Agric., 21(2): 1-14 (2023)