BRRI Dhan29 Research Articles

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.

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.

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)

Late Sowing and Irrigation Cutback Effects on Yield and Economic Performances of Dry Direct Seeded Boro Rice

Dry direct seeding (DDS) is a water saving rice cultivation technology. The sowing of dry direct seeded rice in boro season is generally delayed when grown under the T. aman rice – Rabi crops – DDS boro rice pattern. An experiment was conducted at the Agronomy Field of Bangladesh Agricultural University, Mymensingh to study the effect of sowing date and irrigation schedule on growth and yield of DDS boro rice. The experiment used two sets of treatments (a) two sowing dates viz. 22 February and 13 March; and (b) six irrigation regimes viz. no irrigation, one irrigation at 25% Field Capacity (FC), two irrigations at 25% FC and 1 week after (WA) 25% FC, three irrigations at 25% FC, 1WA 25% FC and 2 WA 25% FC, four irrigations at 25% FC, 1 WA 25% FC, 2 WA 25% FC and 3 WA 25% FC and one irrigation at 3 weeks after 25% FC and the treatments were arranged in a split-plot design with three replications allocating sowing dates into the main plot and irrigation schedule into the subplots. BRRI dhan58 was used as test crop. The result showed that grain yield of the crop did not differ significantly for sowing on 13 March and 22 February. The study revealed that BRRI dhan58 sown on 13 March with four irrigations applied at 25% FC, 1 WA 25% FC, 2 WA 25% FC and 3 WA 25% FC produced the highest economic return and hence it is concluded that the sowing date of boro rice could be delayed up to 13 March with four irrigations. SAARC J. Agric., 21(2): 67-80 (2023)

Effect of Integrated Use of Poultry Manure with Fertilizer Urea for Sustainable Nitrogen Management in Rice (cv. BRRI Dhan 29) under Two Water Management Systems

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh. The experiment's objectives were to evaluate the performance of integrated management of poultry manure with chemical fertilizer urea and to seek water-saving technology that will allow rice (BRRI dhan 29) production to be maintained or increased in the face of declining water availability. The experiment comprised seven treatments viz. T1:100% N from poultry manure, T2:100% N recommended doses of prilled urea, T3:90% N from PU + 10% N from PM, T4:80% N from PU + 20% N from PM, T5: 70% N from PU + 30% N from PM, T6: 60% N from PU + 40% N from PM, T7: 50% N from PU + 50% N from PM. It was laid out in a split-plot design with three replications. The main plots were allocated for irrigation treatments (alternate wetting and dying and continuous flooding) and sub-plots for nitrogen treatments. Altogether, 42 unit plots were conducted, each measuring 2.5mx2.5m. The application of different nitrogen levels significantly influenced all the growth parameters. Irrigation levels significantly affected all the yield and yield contributing characters except plant height, number of ineffective tillers, panicle length, unfilled grain per panicle, 1000 grain weight and harvest index. The highest value of total tiller/hill (11.01), number of effective tillers per hill (9.72), filled grain per panicle (132.23), grain yield (4.80), straw yield (6.68), biological yield (11.47) was observed in the two-irrigation system while height value of non-effective tiller/hill (1.29). The effect of nitrogen treatment was found to be significant. On the other hand, the interaction effect of irrigation management and treatments significantly influenced all the yield parameters except plant height, No. of tiller/ hill, no. of non-effective tiller/hill, panicle length, unfilled grain/panicle and 1000 grain weight. The height value of all those parameters was recorded at the I1×T2 (continuous flooding ×100% N recommended doses of prilled urea). The lowest value of all these parameters was recorded at the I2×T1 (AWDI × 100% N from poultry manure) and I1×T1 (continuous flooding × 100% N from poultry manure). The integrated use of 90% N from PU + 10% N from PM appeared as the better practice because of reducing the considerable amount of prilled urea in Boro rice (cv. BRRI dhan 29) cultivation in terms of grain yield. Moreover, the best promising practice was obtained using 100% N recommended doses of prilled urea applied with continuous flooding (CF).

Callus Induction, Regeneration of Rice Variety BRRI Dhan29 and Determination of Lethal Dose Of Ethyl Methanesulfonate

Rice is an essential meal for a large section of the world's population including Bangladesh. BRRI Dhan29 is known as an excellent rice variety in Bangladesh but it is now susceptible to several diseases and pests, which might reduce rice yields. Therefore, it becomes necessary to explore and optimize different approach with the aim of enhancing yield, diseases resistance and overall genetic variability of this important rice variety. Ethyl methanesulphonate (EMS) produces a large number of non-lethal point mutations by alkylates guanine bases and leads to mispairing-alkylated guanine pairs with thiamine instead of cytosine. The LD50 of EMS is frequently used as a general indicator of a substance's acute toxicity and a lower LD50 is indicative of increased toxicity. This study aimed to develop a comprehensive protocol for callus induction, regeneration for the BRRI dhan29 rice and to determine the LD50% of EMS on callus survival for further genetic improvement. Mature embryos were used to induce callus by utilizing different concentrations (0.00, 0.5, 1.00, 1.50, 2.00, 2.50, 3.00 and 3.50 mg/L) of 2,4-Dichlorophenoxyactic acid (2, 4-D), while callus regeneration was studied using varying combine concentrations of 1-naphthaleneacetic acid (NAA: 0, 5, 10 and 15 μg/L) and kinetin (0.00, 1.00, 2.00 and 3.00 ml/L). The optimal concentrations for callus induction was 2.0 mg/L 2, 4-D and a combination of 10 μg/L NAA and 2.0 mg/L kinetin were identified for efficient callus regeneration. The LD50 of EMS on BRRI dhan29 calli was 0.31%, indicating its potential mutagen for creating genetic variations. Regenerated plants were successfully acclimatized at field conditions. These findings might provide valuable insights for tissue culture-based studies and genetic improvement efforts for the BRRI dhan29. Bangladesh J. Nuclear Agric, 37(1): 1-10, 2023

Determination of Economic Nitrogen Rate for Transplanted Aus Rice Varieties of Bangladesh

A field experiment was conducted at the Agronomy field, Bangladesh Rice Research Institute, Gazipur, Dhaka, from April to September 2019 to determine the economic nitrogen rates for popular transplanted Aus varieties. The experiment was carried out in a randomized complete block design (RCBD), with two factors. Factor A: three varieties as- BR26, BRRI dhan48, and BRRI dhan82; and Factor B: five levels of nitrogen rates as- 0, 40, 60, 80, 100 kg ha−1. The experimental data show the individual effect of variety and nitrogen (N) rate was significant in the case of N concentration, N uptake in grain and straw, and nitrogen harvest index (NHI). Overall, increasing N rate increases grain and straw's concentration irrespective of varieties. But higher N concentration and uptake were observed in the N rate of N60-N100 kg ha−1 in all varieties. Among the varieties, BRRI dhan82 observed higher N uptake (61.23 kg ha−1) in grain. Higher total N uptake was also observed in BRRI dhan48 at 80 kg N ha−1. NHI ranged from 55 to 72 % in different N levels, indicating 55 to 72% of the absorbed N translocated to the grains, and 45% to 32% remained in the dry matter within varieties. The estimated economic nitrogen dose for maximum yield was determined by regression analysis, and found that N rates of BR26, BRRI dhan48, and BRRI dhan82 were 97, 95, and 55 kg ha−1, respectively. The findings of this study indicated that the response of different N rates on three Aus varieties was linear up to 80 kg N ha−1 might be owing to better N uptake that made yield increase after that decreasing.
 Bangladesh Agron. J. 2023, 26(1): 84-95

Effect of Crop Establishment Method and Fertilizer Management on Yield Performance of Boro Rice (Var. Brri DHAN28) In T. Aman-Mustard-Boro Rice Cropping Pattern

The Study was carried out at the Salpoborian village under Sadr papilla of Mymensingh from February to June 2014 to assess the effect of crop establishment method and fertilizer management on the yield performance of Boro rice (var. BRRI dhan28) in T. Aman-Mustard-Boro rice cropping pattern. The experiment comprised three crop establishment methods viz. traditional puddled-transplanting (TPT), unpuddled-one pass in dry condition (UDC), unpuddled-zero tillage (UZT) and five levels of fertilizers viz., 100-60-40-60-10 N-P-K-S-Zn kg ha-1 at recommended (RD) dose (F1), N-K-S-Zn at RD plus 50% P (F2), N-P-S-Zn at RD plus 50% K (F3), P-K-S-Zn at RD plus 75% N as Guti urea (2.7 g/4 hills) (F4), P-K-S-Zn at RD plus 75% N as pilled urea (F5). The experiment was laid out in a split -plot design with 4 replications with crop establishment method in the main- plots and fertilizer management in the sub-plots. Grain yield was not significantly influenced by crop establishment method, fertilizer management and their interactions. However, numerically the maximum grain yield of 3.19 t ha−1 was found in both unpuddled-one pass in dry condition (UDC) and unpuddled-zero tillage (UZT) with 3.32 t ha−1 in P-K-S-Zn at RD plus 75% N as pilled urea (F5) and 3.47 t ha−1 in unpuddled-one pass in dry condition with P-K-S-Zn at RD plus 75% N as pilled urea and traditional puddled-transplanting with P-K-S-Zn at RD plus 75% N as pilled urea. Similar higher gross margin (Tk. 26629 and Tk. 27428) and benefit cost ratio (1.61 and 1.60) was also observed in UZT × F4 and UDC × F5, respectively. So, it can be concluded that unpuddled-zero tillage with P-K-S-Zn at RD plus 75% N as Guti urea (UZT × F4) and unpuddled-one pass in dry condition with P-K-S-Zn at RD plus 75% N as prilled urea (UDC × F5) is the beneficial technique for Boro rice (var. BRRI dhan28) cultivation in T. Aman-Mustard-Boro rice cropping pattern.
 Bangladesh Agron. J. 2023, 26(1): 32-39

Study on growth and yield of some aromatic rice varieties

A field experiment was conducted at Agronomy field of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka during the period from June to December 2017 with seventeen aromatic rice varieties viz., V1= Chiniatap 1, V2= Chiniatap 2, V3= Kataribhog 1, V4= Kataribhog 2, V5= BRRI dhan34, V6= BRRI dhan37, V7= BRRI dhan38, V8= BR5/Dulabhog, V9= Khoisanne, V10 = Sadasanne, V11= Zirabhog, V12= Begun bichi, V13= Shakkhorkhora, V14= Chinigura, V15= Kalijira, V16= Badshabhog, V17= Modhumala to study on growth and yield of some aromatic rice varieties. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Regarding growth and yield parameters, the highest number of total tillers hill−1 (23.33), leaf area index (5.38), flag leaf length (30.12 cm), number of effective tillers hill−1 (21.67), panicle length (32.00 cm), number of grains panicle−1 (230.3), number of filled grains panicle−1 (212.7), grain yield (3.42 t ha−1), straw yield (6.19 t ha−1) and number of biological yield (9.610 t ha−1) were found in var. BRRI dhan37 but the highest 1000- grains weight (22.80 g) and harvest index (37.48%) were found Modhumala followed by BRRI dhan34, respectively. The lowest number of effective tillers hill−1 (13.33), panicle length (24.67 cm), grain yield (1.583 t ha−1), straw yield (4.083 t ha−1), biological yield (5.667 t ha−1) and harvest index (27.89%) were found in the var. Modhumala.
 Bangladesh Agron. J. 2023, 26(1): 1-8

Efficacy of Herbicide Mixtures for Transplanted Aman Rice in Silty Clay Loam Soil of Bangladesh

Weed management plays an important role in obtaining target yield. A field experiment was carried out at the Agronomy field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, from July to December 2019 to get the most effective weed control strategy for transplanted Aman rice. The soil of the study field was silty clay loam in nature. The study consisted of two factors i.e., variety (4: Chinigura, BR11(Mukta), BRRI dhan56, and BRRI hybrid dhan6) and herbicide (4) viz., Bispyribac-sodium WP @ 150 g ha-1, Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1, Pretilachlor 6% + pyrazosulfuron 0.15% WP @ 9.88 kg ha-1, and weedy check as a control. The experiment was laid out in a split-plot design with three replications. Thirteen weed species were found in the experimental plots, mostly broadleaf and sedge. Monochoria vaginalis was the most dominant weed species. The study noticed that the application of mixed herbicides offered better weed control over single herbicide application. Application of Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1 significantly reduced weed density and biomass and was the best way of controlling complex weed flora. The study marked out BR11 (Mukta) as the most potential aman rice variety to produce the highest yields at applying Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1. This treatment gave the highest gross return (Tk. 1,46,010), net return (Tk. 88,699), and benefit-cost ratio (2.55). Therefore, the study suggests the application of mixed herbicides and BR11 (Mukta) to get the optimum yield of transplanted Aman rice and maximum economic benefit.
 Bangladesh Agron. J. 2023, 26(1): 56-74

Variations in the Major Nutrient Composition of Dominant High-Yield Varieties (HYVs) in Parboiled and Polished Rice of Bangladesh.

Rice (Oryza sativa L.) is the principal staple food, a fundamental component of food security, a significant source of energy and major nutrients, and a key player in the overall nutritional status in Bangladesh. Parboiling is a common rice-processing treatment in Bangladesh. Recently, polishing has also become a common practice among millers seeking to attract consumers. Polishing may influence the nutrient composition of rice. The present study aimed to investigate the impact of parboiling and polishing on the nutritional content of the five High Yield Varieties (HYVs) of rice (BR11, BRRI dhan28, BRRI dhan29, BRRI dhan49, and BRRI dhan84) and their percent contributions to the Recommended Dietary Allowances (RDA) of vitamins and minerals. All of the rice samples were analyzed for proximate parameters, vitamins (B1, B2, B3, B6, and folate), and minerals (Ca, Mg, Fe, Zn, Na, K, P). Moisture, ash, fat, and total dietary fiber (TDF) were determined gravimetrically, according to the AOAC Official Methods; protein was measured by the Kjeldahl method; B-group vitamins were measured using Ultra Pressure Liquid Chromatography; and mineral content was determined by ICP-OES. The energy, protein, fat, and total dietary fiber (TDF) content of the samples ranged between 342-357 kcal/100 g, 6.79-10.74 g/100 g, 0.31-1.69 g/100 g, and 2.59-3.92 g/100 g respectively. Thiamin, riboflavin, niacin, pyridoxin, and folate content ranged from 0.11-0.25 mg/100 g, 0.01-0.05 mg/100 g, 2.82-6.42 mg/100 g, 0.12-0.30 g/100 g, and 5.40-23.95 g/100 g respectively. In a comparison of parboiling and polishing, macronutrients and vitamin retention were higher in parboiled unpolished rice than in polished unparboiled rice. The minerals (mg/100 g) Ca, Mg, Fe, Zn, Na, K, and P were in the ranges 32.82-44.72, 30.69-58.34, 0.51-0.70,1.83-2.79, 5.00-5.36, 106.49-112.73, and 162.23-298.03. Minerals of BRRI dhan84 were unaffected by polishing and parboiling. BRRI dhan84 contributed a higher percentage of RDA of all B vitamins and minerals. Therefore, to reduce nutrient loss in rice, industries and consumers should be encouraged to avoid polishing or limit polishing to 10% DOM and to consume unpolished rice, either parboiled or unparboiled.

Analyses of Productivity and Profitability in Boro Rice Cultivation within Blast-Affected Areas of Kushtia District

This study evaluated the profitability dynamics of blast affected Boro rice cultivation within specific regions of Kushtia District of Bangladesh during the period of 2018-19. A total of 90 farmers, with 30 from each upazila, were selected randomly for participation in this study. The findings revealed substantial yield losses, with the most significant impact observed among11% farmers affected by a disease severity scale of 9 in BRRI dhan28, resulting in a yield loss of 3.92 t/ha. Similarly, a blast severity scale of 9 led to yield losses of 2.0 t/ha in BRRI dhan29, affecting 7% of farmers. The Miniket cultivar exhibited a yield loss of 1.70 t/ha among 56% of farmers with a severity scale of 5. Interestingly, Mirpur experienced devastating losses for both BRRI dhan28 and BRRI dhan29, while Kushtia Sadar suffered significant yield losses for the Miniket cultivar based on disease severity and yield impact. Application of Nativo 75 WG (0.40 Kg/ha) and Trooper 75 WP (0.50 Kg/ha) at the lowest (3%) disease incidence resulted in a remarkable 68.97% increase in yield for BRRI dhan29 in Bheramara. Conversely, spraying of Amistar Top 325 SC (0.56 l/ha) did not lead to increase yield. In Miniket cultivar at Bheramara, Nativo 75 WG (0.45 Kg/ha) and Amistar Top 325 SC (0.37 l/ha) resulted in a lower yield of 2.99 t/ha due to application at a higher (50%) disease incidence. Furthermore, a yield increase of 69.67% was observed with the application of Nativo 75 WG (0.34 kg/ha) in the Miniket cultivar at Kushtia Sadar. The highest gross return, gross margin, net return, and benefit-cost ratio were recorded in Bheramara, amounting to Tk 1,24,084/ha, Tk 46,037/ha, Tk 5,797/ha, and 1.05, respectively. Notably, BRRI dhan29 exhibited the maximum gross return and yield of Tk 1,32,435/ha and 6.14 t/ha, respectively, whereas BRRI dhan28 demonstrated the lowest gross return and net return of Tk 1,09,737/ha and (-) Tk 8,321/ha, respectively, due to higher blast disease incidence. Labor costs constituted the largest share (34.10%) of the total rice production expenses. Despite BRRI dhan28 exhibiting lower net and gross returns per hectare due to higher blast disease incidence, the highest yields in BRRI dhan29 were attributed to its comparatively lower disease infection rate among the three varieties. Evidently, the cultivation of the Miniket cultivar resulted in higher net returns due to its superior market price and quality, especially when disease incidence was lower compared to BRRI dhan28. This emphasizes the importance of blast management strategies and the use of resistant varieties with high yield potential and market value in ensuring sustainable productivity and profitability in Boro rice production. Bangladesh Rice J. 26 (2): 1-18, 2022

Blast Disease Behavior in Some Boro Rice Varieties of Bangladesh and Development of Induced Resistance System Against Blast Disease through Selected Novel Chemicals

Chronologically two experiments have been conducted during the period from October 2018 to May 2019 and July 2019 to June 2020 at Sher-e-Bangla Agricultural University, Bangladesh for the identification of one of the best rice varieties and chemicals against blast disease. In a field experiment, eight boro rice varieties were evaluated (five inbreed varieties, two high-yielding varieties, and one wild variety) to observe varietal performances against blast disease. A pot experiment was also performed to study the resistance behavior of the tested varieties in an in-vitro condition by applying silica powder, K2SiO3, salicylic acid, cattle urine (both normal and pregnant cows), and PPN. Field study revealed that the wild variety was highly resistant (incidence and severity 0%) whereas BRRI dhan58 was susceptible (incidence 21.48% and severity 60.48%). Wild variety was also characterized by the highest tiller number (20.73), panicle length (24.90 cm), fresh grain weight (62.30 g), and dry grain weight (51.70 g). The highest number of panicles was recorded in BRRI dhan28 (18.40) which was statistically like the wild variety (17.50). Though wild variety performed best in another parameter it gave the lowest amount of yield (4.77 kg/plot). In morphological studies of pathogen, pyriform-shaped conidia were found in a sympodial fashion on conidiophores whose size varied from 22.13 to 28.47 μm × 9.13 to 11.72 μm (average 25.30×10.43 μm). The second experiment revealed that all selected novel chemicals showed some extent of resistance but the cattle urine, PPN, and K2SiO3 showed a promising effect. Koch’s postulate test for the experiment confirmed the causal organism of blast disease is Magnaporthe oryzaein artificially inoculated plants.

Variability in 2-acetyl-1-pyrroline production and associated mutations in BADH2 gene in aromatic rice cultivars of Bangladesh

Aroma is a special trait and aspect of the end-use quality of rice and its principal component is 2-acetyl-1-pyrroline (2AP). Sequence variants of betaine aldehyde dehydrogenase (BADH2) gene on rice chromosome 8 are associated with fragrance, and the most prominent mutation is an 8-bp deletion and three single nucleotide polymorphisms (SNPs) in exon 7. In this study, we analyzed sequence variations in exon 7 of BADH2 in four locally popular aromatic rice cultivars and six non-aromatic high-yielding rice varieties in Bangladesh. Sequencing and alignment analysis revealed that two aromatic rice cultivars, Kataribhog and Sakkorkhana, had an 8-bp deletion (discontinuous) and one SNP (A/T) in exon 7 of the BADH2 gene. However, deletions were absent in the other two aromatic rice cultivars (Chinigura and Ranisalut) and all high-yielding varieties (BRRI dhan28, BRRI dhan29, BRRI dhan86, BRRI dhan87, BRRI dhan92 and BINA dhan10). Gene expression analysis using specific markers also supports these findings. Our results suggest that aromaticity in local rice cultivars in Bangladesh may be regulated by differential genetic mechanisms. Further studies are needed to elucidate the genetic mechanisms and fragrant compound(s) involved in the fragrance traits of Chinigura, Ranisalut, and other locally cultivated aromatic rice varieties that are critical for the development of high-yield aromatic rice by knocking out the targeted gene(s) using CRISPR-Cas genome editing.

COMPARISON OF GROWTH AND YIELD PERFORMANCE OF RICE VARIETIES UNDER THREE AGRO ECOLOGICAL ZONE

The experiment was conducted to study “COMPARISON OF GROWTH AND YIELD PERFORMANCE OF RICE VARIETIES UNDER THREE AGR0ECOLOGICAL ZONE”. The experiment consisted of five varieties viz, two inbred variety; BRRI dhan-28, BRRI dhan-29 and three hybrid variety: Surma-2, BRRI hybrid dhan-2, Hira-5; three regions viz. Rajshahi, Rangpur and Bogra. The experiment was laid out in a randomized complete block design with three replications. Among the tested varieties BRRI dhan-29 produced highest grain yield (7.97 t ha-1) which was significantly superior to all other varieties and lowest grain yield (5.21 t ha-1) was produced Surma-2 in Rajshahi region. Hira-5 produced highest grain yield (8.81 t ha-1) which was significantly superior to all other varieties and lowest grain yield (6.40 t ha-1) was produced BRRI dhan-28 in Rangpur region. Surma-2 produced highest grain yield (9.48 tha-1) which was significantly superior to all other varieties and BRRI dhan-28 produced the lowest grain yield (6.79 t ha-1) in Bogra region. All the yield contributing measurements of rice varieties showed variability in different region. The result summarized that hybrid variety showed superior performance in comparison with inbred variety (2010-2011).

Comparative Efficacy of Foliar Plus Soil Application of Urea versus Conventional Application Methods for Enhanced Growth, Yield, Agronomic Efficiency, and Economic Benefits in Rice.

The experiment was conducted at the research field, Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur from December 2017 to May 2018 to find out the best treatment of foliar application of urea on the growth and yield of boro rice cv. BRRI dhan28. The experiment consisted of 10 treatments, laid out in a randomized complete block design in triplicate. The recommended doses (RD) of urea, TSP, MOP, gypsum, ZnSO4, and borax were applied during land preparation except for urea at 250, 75, 100, 75, 7, and 5 kg ha-1, respectively, where urea was applied as per treatment specification. The results revealed that the application of N fertilizer as foliage along with soil significantly influenced the growth, plant characteristics, and yield of BRRI dhan28. There was no significant difference between T8 (70% in soil and 10% as foliage) and T9 (100% in soil) treatment regarding the maximum panicle length (21.43 and 20.71 cm), fertile grains (117.40 and 113.30), total grains (134.40 and 130.97), 1000-grain weight (24.56 and 23.56 g), grain yield (5.91 and 5.74 t ha-1), straw yield (7.83 and 7.92 t ha-1), biological yield (13.74 and 13.66 t ha-1), and harvest index (43.01 and 42.02%), respectively, in this study. These results indicated that N fertilization as direct soil application (70%) and as foliage application (10%), i.e., 80% N fertilization, produced the highest grain yield and major yield traits which we received by 100% N fertilization as soil that was practiced traditionally by the farmers. The effect of overfertilization (T10) was not positive, producing the highest number of noneffective tillers and sterile grains (nonfilled grains). Therefore, it is possible to achieve an equivalent or more yield by saving 20% urea by the combination of soil (70%) and foliage (10%) application as compared to the traditional method of fertilizer application (100% in soil).