BRRI Dhan29 Research Articles

Bacterial endophyte Pseudomonas mosselii PR5 improves growth, nutrient accumulation, and yield of rice (Oryza sativa L.) through various application methods

BackgroundPseudomonas spp. have drawn considerable attention due to their rhizospheric abundance and exceptional plant growth-promoting attributes. However, more research is needed on the optimal application methods of Pseudomonas mosselii for rice growth, nutrient accumulation, and yield improvement. This research explored the application of the endophytic bacterium P. mosselii PR5 on rice cultivar BRRI dhan29 with four treatments: control, seedling priming, root drenching, and bacterial cell-free culture (CFC) foliar application.ResultsPR5 led to better rice growth, improved nutrient acquisition, and higher yields compared to the control, regardless of the application method used. The highest results in fresh weight of root (146.93 g/pot), shoot (758.98 g/pot), and flag leaf (7.88 g/pot), dry weight of root (42.16 g/pot), shoot (97.32 g/pot), and flag leaf (2.69 g/pot), and grains/panicle (224.67), were obtained from seedling priming treatment, whereas root drenching resulted in maximum plant height (105.67 cm), root length (49.0 cm), tillers/pot (23.7), and panicles/pot (17.67). In all three application methods, rice grain yield per pot was higher in PR5 inoculated treatments, compared to the control. The amount of P, Mg and Zn in the shoot and N, P, Ca, Mg and Si content in the flag leaf was significantly increased along with effective suppression of naturally occurring blast disease in bacterial CFC foliar application, validated by multivariate analysis.ConclusionOur results indicated that rice seedlings priming with PR5 improved rice growth, yield and nutrient uptake, whereas CFC foliar application significantly increased the concentration of most nutrients in the rice plant and suppressed the naturally occurring rice blast disease. This research highlights the significant potential of P. mosselii PR5 in enhancing rice growth, yield, and nutrient uptake, particularly through seedling priming and CFC foliar application methods.

Presumption of Herbicide Resistant Weeds and Yield of Boro Rice as Influenced by Pre- and Post-emergence Herbicides

In Bangladesh, weed infestation is a leading problem in rice cultivation and the sole dependency on post-emergence herbicides is ineffective. Therefore, a field experiment was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from December 2021 to May 2022. The study was done to determine the relative effectiveness of different pre-emergence herbicides and to presume the herbicide-resistant weeds and yield of boro rice as influenced by pre-and post-emergence herbicides. Four rice varieties: BAU dhan3 (V1), BRRI dhan28 (V2), BRRI dhan81 (V3), BRRI dhan96 (V4) and six herbicide managements: Control (H1), Hand Weeding at 30 DAT (H2), Bensulfuron methyl @ 980 g ha-1 (H3), Pretilachlor @ 2 L ha-1 (H4), Carfentrazon ethyl @ 208 mL ha-1 (H5), Ethoxisulfuron @ 200 g ha-1 (H6) were used in a randomized complete block design (RCBD) with three replications. The most dominant weed species in the experimental plots were Echinochloa crussgalli, Scirpus mucronatus, Monochoria hastata, Enhydra fluctuans and Oxalis europaea. This study found Ethoxisulfuron (H6) and Carfentrazon ethyl (H5) were the most effective weed management treatments for weed suppression and grain yield at twice the recommended doses. In this study, the highest grain yield (5.40 t ha-1), straw yield (6.80 t ha-1) and biological yield (12.20 t ha-1) were obtained from BRRI dhan81 (V3) with hand weeding (H2) and highest harvest index (45.60%) were obtained from BAU dhan3 (V1) with Pretilachlor (H4). Therefore, this result is useful for farmers at field level cultivation of boro rice.

Allelopathic Effects of Residues of Fimbristylis dichotoma Along with Manures and Fertilizers on the Weed Growth in Boro Rice

Currently, the rice-growing system seeks a biological solution to reduce the negative impacts of chemical herbicides because it is heavily reliant on these for weed control. This is where allelopathy comes in; it's a potential substitute for conventional weed management strategies in rice cultivation by making use of allelopathic plant residues. In the study we used Fimbristylis dichotoma residues with several organic sources of nutrient to measure the integrated effect of manures, fertilizers, and Fimbristylis dichotoma residues on weed growth in boro rice field. Two rice varieties viz., BRRI dhan29 and BRRI dhan89; and six treatments total viz., Control (T1), Residues @ 3 t ha-1 + Recommended doses of inorganic fertilizers (T2), Residues @ 3 t ha-1 + Tricho-compost @5 t ha-1 (T3), Residues @ 3 t ha-1 + Tricho-compost @1.5 t ha-1 + 25% less than recommended doses of inorganic fertilizers (T4), Residues @ 3 t ha-1 + Tricho-compost @2.5 t ha-1 + 50% less than recommended doses of inorganic fertilizers (T5) and Residues @ 3 t ha-1 + Tricho-compost @3.75 t ha-1 + 75% less than recommended doses of inorganic fertilizers (T6) were taken. In the experiment, at 25 DAT (days after transplanting), BRRI dhan89 had the highest weed density (35.0) when no residue was applied, and BRRI dhan29 had the lowest (18.00) when 3 t ha-1 F. dichotoma residue with Tricho-compost @ 1.5 t ha-1 + 25% less than recommended doses of inorganic fertilizers were applied. At 55 DAT, BRRI dhan89 had the highest weed density (19.66) when no residue was administered, and the lowest (10.66) when 3 t ha-1 F. dichotoma residue was applied along with Tricho-compost @ 1.5 t ha-1 + 25% less than recommended doses of inorganic fertilizers. When it came to dry weight, at 25 DAT, BRRI dhan89 had the highest weed dry weight (3.76 g) when no residue was applied, and BRRI dhan29 had the lowest (1.72 g) when 3 t ha-1 F. dichotoma residue with Tricho-compost @1.5 t ha-1 + 25% less than recommended doses of inorganic fertilizers were applied. At 55 DAT, BRRI dhan89 had the highest weed dry weight (2.29 g) when no residue was sprayed, and the lowest (1.46 g) when 3 t ha-1 F. dichotoma residue with Tricho-compost @ 1.5 t ha-1 + 25% less than recommended doses of inorganic fertilizers were applied. The study's findings suggest that applying F. dichotoma residue and incorporating Tricho-compost @ 1.5 t ha-1 + 25% less than the recommended amounts of inorganic fertilizers may be able to suppress the growth of weeds and could a package in biological weed control strategy.

Regulation of eating quality, sensory aroma and 2-acetyl-1-pyrroline biosynthesis in fragrant rice through foliage application of aromatic compounds

The experiment was conducted at the research area of Sher-e-Bangla Agricultural University from 15 June 2022, to 25 November 2022 (Aman season) to evaluate the impact of aromatic compound application on fragrant rice. The experiment included two factors: factor 1 comprised four rice varieties (BRRI dhan34, BRRI dhan70, BRRI dhan80, and Tulshimala), and factor 2 comprised application of four aromatic compounds (L-proline, α-ketoglutaric acid, γ-aminobutyric acid, and sodium selenite). A randomized complete block design was employed with three replications. Results revealed significant effects of aromatic compound applications and/or rice varieties on grain eating qualities, sensory aroma and 2-acetyl-1-pyrroline, which were superior in Tulshimala and BRRI dhan34. α-Ketoglutaric acid and sodium selenite application improved water uptake ratio, amylose and amylopectin content, alkali spreading value, gel consistency, protein content, sensory aroma score, and kernel stickiness and tenderness of fragrant rice. Moreover, α-ketoglutaric acid application led to enhanced 2-acetyl-1-pyrroline content in Tulshimala and BRRI dhan34. Several eating quality and fragrance parameters were found either positively or negatively correlated. Apparent amylose content exhibited a negative correlation with stickiness of kernel. Sensory aroma and grain 2-AP content were also positively correlated.

Study of Genetic Diversity of Aromatic Rice Genotypes Using Random Amplified Polymorphic DNA Markers

The study of genetic variation in aromatic rice is necessary for enhancing and preserving its genetic makeup. In this study, we amplified four Random Amplified Polymorphic DNA (RAPD) markers from the genomes of 11 different aromatic rice genotypes in order to evaluate the genetic variation and relatedness in aromatic rice. The genotypes were collected from different sources- five of which were obtained from the Bangladesh Rice Research Institute, one from the Bangladesh Institute of Nuclear Agriculture, and the remaining five were local genotypes. In RAPD profiling, twenty-seven of the thirty-six bands that were generated by the four primers were polymorphic, resulting in an estimated average polymorphism of 47.22 percent. The average value of the polymorphic information content was 0.309 with a range from 0.165 to 0.456, indicating that the primers were effective to detect genetic diversity between the genotypes. The genetic diversity and Shannon information index across all of the genotypes and primers were 0.176 and 0.260, respectively, which indicated that there was a certain amount of genetic variation in the studied aromatic rice genotypes. Kalizira and Binadhan-9 genotypes had the smallest genetic distance (0.057), while it was the highest (0.406) between the BRRI dhan 34 and BRRI dhan 50. The genotype pairs BRRI dhan 38 vs BRRI dhan 34, BRRI dhan 38 and Kalizira, and Zirakatari and Kalizira had also a higher level (0.365) of genetic distances. The genotypes were grouped into two main clusters in the UPGMA dendrogram. Cluster I included five genotypes: BRRI dhan 34, Basmoti, Atashail, Kalizira, and Binadhan-9. Cluster II included remaining six genotypes: BR5, BRRI dhan 38, BRRI dhan 50, Uknimodhu, BRRI dhan 37, and Zirakatari. Documentation of the genetic variation and relatedness among the aromatic rice genotypes under this investigation could be useful for future research into the development of aromatic rice and related fields. J Bangladesh Agril Univ 22(3): 277-284, 2024

Pyramiding of multiple resistant genes of blast and bacterial blight diseases in the background of rice (Oryza sativa) mega variety BRRI dhan29

Blast and bacterial blight (BB) are the two major rice diseases in the world including Bangladesh. In this study, BB resistance genes (Xa21 and xa13) and blast resistance (Pi9 and Pb1) genes were pyramided into a mega variety, BRRI dhan29 through marker-assisted backcross breeding. IRBB58 was used as a BB-resistant donor and Pi9-US2, and Pb1-US2 were used as blast-resistant donors. Backcross was done between BRRI dhan29 and donor parents to develop BC3F1 population and then selfing was done to develop BC3F6 population. BC3F2 population was genotyped and phenotyped for segregation analysis and BC3F6 was evaluated for genotyping, phenotyping and morphological traits and yields. Chi-square analysis of BC3F2 data revealed that blast and BB resistance followed the single gene mendelian fashion (1:2:1 and 3:1). Two to four gene combinations were found in the advanced lines of the BC3F6 population. The yield of the advanced lines ranged from 6.42 (t ha-1) to 9.5 (t ha-1) and they showed resistant against blast and BB with mean disease scores ranging from 0.67 to 2.33 and 0.33 to 2.33, respectively. Finally, eight lines having four genes (xa13, Xa21, Pi9 and Pb1) were selected for multilocational (five locations) trials for yield performance and disease reaction. Mean yield data of eight advanced lines of all locations were varied from 6.48±0.15 to 8.38±0.11 t ha-1 and all the lines showed resistant reactions against blast (score 0.53 to 1) and BB (score 0.6 to 0.87) disease. The highest yield was found in BR (Path) 13800-BC3-224-12 (G28, 8.38±0.11 t ha-1) followed by BR (Path) 13800-BC3-134-252 (G26, 8.28±0.08 t ha-1) and BR (Path) 13800-BC3-136-115 (G12, 8.24±0.07 t ha-1). Pyramided advanced lines of this study could be released as BB and blast-resistant varieties or could be utilized as donor parents in resistant breeding.

Influence of Grass Pea Residues Extract on Weed Control Efficacy and Performance of Boro Rice

The agriculture sector is constantly adopting environmentally friendly and sustainable methods to reduce the harmful effects of herbicides on crop production. In this respect, an experiment was conducted at the Agronomy Field Laboratory (AFL), Bangladesh Agricultural University (BAU), Mymensingh to assess the allelopathic effects of grass pea crop residues on weed suppression and the growth performance of Boro rice from December 2021 to May 2022. The experiment consisted of four cultivars of Boro rice i.e. BAU dhan3, BRRI dhan28, BRRI dhan81, BRRI dhan96 along with four different treatments of weed control viz. no extract and no weeding (control), hot water extract of Grass pea residues as pre-emergence application at 3 DAT (days after transplanting), hot water extract of Grass pea residues as pre-emergence application at 3 DAT+ post- emergence at 10 DAT, hand weeding 3 times at 15, 30 and 45 DAT. The highest weed growth was noticed when no extract was added and the lowest was found when three times hand weeding was performed. The highest number of effective tillers (NET) hill-1, number of spikelets panicle-1 (NSP) and grain yield (GY), straw yield (SY) and biological yield (BY) were recorded from the rice variety BAU dhan3. The highest NET hill-1, NSP, 1000-grain weight (TGW), GY, SY and BY were recorded from three hand weeding which was followed by hot water extract of grass pea as pre-emergence application at 3 DAT+ post-emergence application at 10 DAT. From the interaction it is observed that the highest NET hill-1, NSP, SY and BY were obtained from BAU dhan3 with three hand weeding which was followed by BAU dhan3 with hot water extract of grass pea as pre-emergence application at 3 DAT+ post-emergence application at 10 DAT. The findings of this study reveal that hand weeding, followed by the application of grass pea crop residues, effectively suppresses weed growth. Our research suggested leveraging the allelopathy-weed inverse relationship to address weed problems. This approach holds significant promise for weed management in the twenty-first century. J Bangladesh Agril Univ 22(3):360-368, 2024

Allelopathic effects of leaves extract of parthenium hysterophorus l. On seed germination of three Rice varieties

This study investigates the allelopathic effects of Parthenium hysterophorus L. leaf and root extracts on the germination and growth of three rice varieties (Hira dhan, BRRI dhan-28, and BRRI dhan-29) in Bangladesh. Leaf and root extracts of P. hysterophorus were prepared at different concentrations and applied to rice seeds in a controlled environment. Results showed that low concentrations of the extracts inhibited seed germination and growth, with significant differences among rice varieties (p < 0.05). Hira dhan exhibited the most sensitivity, with germination rates as low as 42.86% under high extract concentrations. In contrast, BRRI dhan-29 showed a stimulatory effect, particularly at low concentrations. The shoot and root lengths of Hira dhan and BRRI dhan-29 were significantly inhibited at higher concentrations, while BRRI dhan-28 demonstrated growth stimulation. The fresh and dry weights of roots and shoots varied significantly among the varieties with the greatest inhibitory effect observed in BRRI dhan-29. These findings align with previous studies, suggesting that allelochemicals in P. hysterophorus, such as parthenin and phenolic acids, play a critical role in inhibiting rice growth. The study emphasizes the need for further research on allelopathic interactions and suggests that controlling P. hysterophorus at the crop emergence stage could mitigate its suppressive effects on rice growth. Bangladesh J. Bot. 53(3): 411-421, 2024 (September)

Phylogenetic analyses and pathogenic diversity of Meloidogyne graminicola of rice (cv. BRRI Dhan28) from different agro-ecological zones of Bangladesh

Rice root-knot caused by Meloidogyne graminicola is a major yield-limiting factor in all rice growing countries around the world, which is often ignored in Bangladesh due to its subtle and obscure above ground symptoms. The current study proposes a comprehensive diagnosis of rice root-knot nematode at the molecular level and analyzes the pathogenic diversity of M. graminicola population of different AEZs. Rice seedlings of a popular variety (BRRI Dhan28) showing galls in the roots were collected from thirty Agro-Ecological-Zones (AEZs) of Bangladesh. For molecular identification, nuclear DNA was collected from single second-stage juvenile and internal transcribed spacer (ITS) was used as a universal primer. Molecular identification and phylogenetic analyses revealed that all nematode populations of galled rice seedlings from different locations belong to M. graminicola. The nematode populations constitute six phylogenetic clades. Nematode population of phylogenetic clade II showed the highest no. of galls (178 ± 1.67), although galling index was higher and similar in clade I, clade-II, clade-III and clade-VI. The highest percent reduction in both vegetative and yield-contributing traits were recorded in clade-II. A negative correlation was found in galling incidence and all growth and yield parameters. Comparative hatching of M. graminicola from different locations reveals that the pathogenicity of M. graminicola depends on the genetic variability of the nematode population, but not on the hatched juveniles. It might be concluded that the rice root-knot nematodes (M. graminicola) are prevalent in all agro-ecological zones of Bangladesh, despite the most pathogenic groups being frequent in AEZ- 1, 6, 7, 10, 18, 19, 21 and appropriate management initiatives are therefore crucial for maximizing rice yield.

Combined hot water extract of lentil and grass pea increase weed control efficiency and yield of boro rice

The agriculture sector is continuously adopting environmentally friendly and sustainable methods to reduce the harmful effects of herbicides on crop production. In this context, an experiment was conducted at the Agronomy Field Laboratory (AFL), Bangladesh Agricultural University (BAU), Mymensingh, from December 2021 to May 2022, to investigate the effect of combined hot water extracts of lentil and grass peas (ELG) on weed control efficiency and yield performance of boro rice. The experiment involved four varieties of boro rice (BAU dhan3, BRRI dhan28, BRRI dhan81, and BRRI dhan96) and four treatments of crop residues. For most weed species, varieties and crop residue extracts significantly impacted weed population (WP) and weed dry weight (DW). The highest numbers of effective tillers (NET) hill-1, numbers of spikelets panicle-1 (NSP), 1000-grain weight (TGW), grain yield (GY), and straw yield (SY) were observed in the three-times hand weeding treatment. This was followed by the combination of hot water ELG applied as a pre-emergence treatment three days after transplanting and post-emergence ten days after transplanting, with the lowest values found in the no-extract treatment. Considering interaction effects, the highest GY (7.07 t ha-1) and SY (8.23 t ha-1) were observed with hand weeding combined with the variety BAU dhan3. The results of this study indicated that hand weeding, followed by the combined application ELG crop residue, showed potential activity to suppress WP and significantly affected the yield of boro rice.

Yield performance of aromatic fine rice as influenced by nitrogen fertilization and weed control techniques

Nitrogen fertilization and weed management is the major concern to yield maximization of rice. The study was conducted to assess the influence of nitrogen and weed control to yield improvement of aromatic rice BRRI dhan34. The experiment included three nitrogen levels viz. 50, 100 and 150 kg N ha-1 as well as three weeding schedules viz. one hand weeding at 15 days after transplanting (DAT), two hand weeding at 15 and 30 DAT and three hand weeding at 15, 30 and 45 DAT. The experiment was conducted with randomized complete block design. The findings demonstrated important correlations between weeding techniques, nitrogen levels and yield components. When the crop was fertilized with 50 kg N ha-1 the highest numbers of total tillers hill-1 (8.53), effective tillers hill-1 (7.51), grains panicle-1 (128.0) and grain yield (3.97 t ha-1) were resulted. Regarding weeding practices, two manual weeding carried out at 15 and 30 DAT reported the highest numbers of effective tillers hill-1 (7.62), grains panicle-1 (128.1) and grain yield (4.10 t ha-1). The highest effective tillers hill-1 (8.33), the most grains panicle-1 (129.8), the grain yield (4.36 t ha-1) and straw yield (6.40 t ha-1) were found in two hand weeding at 15 and 30 DAT combined with 50 kg N ha-1 and the lowest grain yield (3.53 t ha-1) was obtained from one hand weeding given at 15 DAT along with 150 kg N ha-1. Therefore, the study demonstrated that BRRI dhan34 can be fertilized with 50 kg N ha-1 along with two hand weeding at 15 and 30 DAT to obtained higher yield.

Effect of Bispyribac-Sodium and Spacing on The Weed Control and Performance of Aromatic Rice Varieties

Rice (Oryza sativa L.), a staple grain, serves as a fundamental dietary component for billions by providing carbohydrates, vitamins, and minerals, supporting livelihoods, and stimulating national economies. A field experiment was led from July to December 2019 at the Sher-e-Bangla Agricultural University’s agronomy field in Dhaka, Bangladesh, to determine how a post-emergent herbicide and spacing impacts aromatic rice varieties' growth, yield, and weed control. The investigation consisted of three factors, i.e., weed control treatments: weedy check (no weeding) and Bispyribac-sodium WP @ 150 g ha−1, aromatic rice varieties: Kalizira and BRRI dhan37 and spacing: 20 cm × 15 cm, 25 cm × 15 cm, 20 cm × 20 cm, and 25 cm × 25 cm in a split-split plot design with three replications. Thirteen dissimilar types of weeds invaded the experimental plots. Among them, Monochoria vaginalis was the most prevalent weed at 30 and 60 DAT (24.67 and 19.67 weed population m−2 and 15.24 and 13.02% relative weed density sequentially). Among all the factors, the application of Bispyribacsodium WP (W1), BRRI dhan47 (V2, grain yield 2.99 t ha−1) and 20 cm × 20 cm (S3, grain yield 2.87 t ha−1) spacing provided promising results. According to the findings, BRRI dhan37 planted at 20 cm × 20 cm spacing, along with the suggested application of Bispyribac-sodium WP could provide the best result. Bangladesh Agron. J. 2024, 26(2): 56-66

Foliar Fertilization on BRRI dhan28 To Reduce Soil Application of Nitrogenous Fertilizer

The experiment was conducted at the research farm of Crop Physiology and Ecology Department, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during November 2019 to June 2020 to find out the effect of foliar fertilization on the performance of rice var. BRRI dhan28 and to estimate how much nitrogenous fertilizer can be saved by foliar fertilization without yield reduction. The experiment was laid out following split plot design with three replications. Four levels of foliar fertilization (F0 – No foliar fertilization, F1 – Foliar fertilization with 2% KNO3, F2 - Foliar fertilization with 2% DAP and F3 - Foliar fertilization with 1% American NPKS) were placed in the main plot treatments whereas three nitrogen fertilizer levels (N50 -50% of the recommended nitrogen fertilizer, N75 – 75% of the recommended nitrogen fertilizer and N100 – 100% of the recommended nitrogen fertilizer) were placed randomly in the sub-plots. Foliar fertilization with KNO3, DAP (Di-ammonium phosphate) and American NPKS significantly increased the grain yield (t ha−1) compare to control (F0) but KNO3 and American NPKS performed better than DAP. Foliar fertilization with KNO3 and American NPKS could save 25% of recommended nitrogen fertilizer but foliar fertilization with DAP could not save nitrogen fertilizer applied in soil for getting comparable grain yield found in F0N100. Foliar fertilization of KNO3 and American NPKS with recommended nitrogen fertilizer applied in soil could increase 11.8 and 12.5% grain yield, respectively compare to F0N100. Bangladesh Agron. J. 2024, 26(2): 77-85

Mitigation of salt stress in rice (oryza sativa l.) growth and yield in coastal saline soil using crop residue-driven organic amendments under varying moisture conditions

The increasing salinity in coastal areas due to climate change significantly hinders rice (Oryza sativa L.) production, a crucial food source for over half of the global population. This study evaluates the effects of organic amendments and moisture conditions on the vegetative growth and yield of rice varieties in a saline field in the Khulna district of Bangladesh. The field experiment was conducted from February to May 2020, using rice straw compost (RSC), sawdust (SD), rice husk (RH), and mustard seed meal (MSM) at varying rates (0, 5, 10, 15 t ha-1) under moist (70% soil moisture) and saturated (>100% soil moisture) conditions. The experiment featured BRRI dhan 28 (salt-sensitive) and BRRI dhan 47 (salt-tolerant) varieties. Key metrics evaluated in the study included the productive to unproductive tillers ratio (PTR), spikelet sterility, percent filled grains, straw yield, and grain yield. Results indicated significant (p ≤0.05) improvements in PTR, reduction in spikelet sterility, increased grain filling, and higher straw and grain yields with applying organic amendments, especially MSM. The highest PTR for BRRI dhan 47 (0.86) was achieved with MSM at 5 t ha-1 under moist conditions, while BRRI dhan 28 reached a PTR of 0.81 with RH at 10 t ha-1 under saturated conditions. Spikelet sterility was minimized (9/panicle) with MSM at 5 t ha-1 under saturated conditions for both varieties. Percent filled grains peaked (88.9%) with MSM at 5 t ha-1 for BRRI dhan 28. Enhanced straw yields were observed, with BRRI dhan 47 achieving 8.76 t ha-1 with MSM at 10 t ha-1. Grain yield increased significantly, with BRRI dhan 28 yielding 5.75 t ha-1 under similar conditions. The study confirms that organic amendments of MSM > RSC > SD > RH can effectively mitigate salt and moisture stress, thereby improving rice productivity in saline soils. Dhaka Univ. J. Biol. Sci. 33(2): 1-13, 2024 (July)

Evaluation of Transplanted Aman Rice by Exploiting and Adjusting Existing Technologies

Varietal differences are a common occurrence in rice cultivation across Bangladesh. Moreover, the application of appropriate management practices (MP) is essential for optimal rice production. Against this backdrop, a study was conducted at the Agronomy Field Laboratory (AFL) of Bangladesh Agricultural University (BAU), Mymensingh, during the aman season from July to December 2023. The aim was to assess the impact of different varieties and MP on the yield and other related attributes of Transplanted Aman (T. aman) rice. The study featured five rice varieties: BR11, BRRI dhan49, BRRI dhan52, BRRI dhan75, and BRRI dhan87 and two MP, namely Farmers’ Practices (FP) and Improved Practices (IP). The experimental design was a split plot, with MP as the main plots and varieties as the subplots, replicated three times. The findings indicated that both the variety of rice and the MP significantly influenced the yield and yield-related traits. Specifically, the variety BRRI dhan87 showed superior performance, yielding the highest plant height (PH) (116.87 cm), panicle length (PL) (25.33 cm), number of effective tillers (NET) hiil-1 (10.33), number of grains panicle-1 (NGP) (129.04), 1000 grain weight (TGW) (26.03 g), Biological yield (BY) (11.88 t ha-1), grain yield (GY) (5.69 t ha-1), Harvest index (HI) (47.81%). Under the MP, the IP recorded the highest NET hiil-1 (10.47), NGP (119.35), and GY (5.48 t ha-1), showing a 13.14% increase in GY over the FP. The combination of BRRI dhan87 and IP achieved the highest GY (6.31 t ha-1). The study concludes that the highest GY of T. aman rice can be achieved by cultivating BRRI dhan87 with IP, although further trials at various locations are recommended before drawing final conclusions.

Biochar in conjunction with reduced doses of mineral fertilizers increased yield attributes and yield of rice (cv. BRRI dhan29)

Biochar in conjunction with reduced doses of mineral fertilizers increased yield attributes and yield of rice (cv. BRRI dhan29)

Assessing Herbicide-Resistance and Yield Optimization in Boro Rice (cv. BRRI dhan29) through Post-emergence Herbicides Applications

Effective weed management is crucial for achieving optimal crop performance and yield in rice cultivation. While post-emergence herbicides are commonly used to control weed population (WP), their effectiveness can vary based on the dosage and combinations applied. In this respect, an experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, from December 2019 to May 2020 to predict herbicide-resistant weeds and assess the yield of boro (dry season irrigated) rice (cv. BRRI dhan29) in response to post-emergence herbicides. The experiment consisted of five post-emergence herbicides: Fenoxaprop-p-ethyl, Triafamone, Penoxsulam, Bispyribac-sodium, and Carfentrazone-ethyl, and four doses of herbicide: control, half of the recommended dose (RD), RD, and double the RD. Weed dry weight (DW), WP, and inhibition were significantly affected by different doses of herbicides. Ten weed species (WS) belonging to four families infested the experimental plots, with the most dominant being Echinochloa crus-galli, Scirpus mucronatus, and Scirpus articulatus. The lowest WP and DW, as well as the highest weed control efficiency (WCE), were achieved with double the RD of Penoxsulam and Triafamone, showing 91.09% and 90.13% efficiency, respectively, at 30 DAT. The tallest plants, highest number of effective tillers hill-1, highest grain yield, straw yield, biological yield, and harvest index were found with double the RD of Penoxsulam. In contrast double the RD of Triafamone produced the second-highest grain yield. Although double doses of herbicides increased yield, the variation was not significantly greater than the RD. Some weeds, particularly E. crus-galli, S. articulatus, Leersia hexandra, and Digitaria sanguinalis, survived even with double the RD of herbicides. This indicates a potential for herbicide-resistant weeds.

Sustainable improvement of rice growth under salinity stress using an endophytic fungus-based biofertilizer

Salinity stress adversely affects rice (Oryza sativa L.) growth, development and overall productivity. Multiple strategies have been implemented to enhance the resilience of rice plants, enabling them to grow better in saline environments. Use of biofertilizers, a sustainable alternative to chemical fertilizers, has gained significant attention in modern agriculture due to their potential to improve soil fertility, enhance crop productivity, and mitigate environmental concerns. Biofertilizers encompass a diverse group of microorganisms, including bacteria, fungi, and algae, which interact with plants through various mechanisms. These beneficial microbes have been reported to convert atmospheric nitrogen into plant-available forms and break down insoluble phosphates and zinc complexes in the soil. Additionally, they can also produce growth regulators, enhance nutrient availability, and protect plants against pathogens. In our previous study, a salt-tolerant endophytic fungus isolated from the halophytic wild rice, Oryza coarctata, was identified as Aspergillus welwitschiae Ocstreb1 by whole genome sequence analysis. During the in-vitro experiments, the endophyte showed several plant growth promoting activities such as, zinc and phosphate solubilization, siderophore, IAA, and ACC-deaminase production, nitrogen fixation, etc. in both normal and 900 mM salt stress. In this study, the endophyte was used to formulate a biofertilizer in combination with talcum powder to enhance the growth and yield of rice plants under salinity stress. This research investigated the effectiveness of the biofertilizer in four distinct salinity tanks under both non-saline and 6 dS/m saline conditions, each containing three different varieties of rice. Treatment of BRRI dhan28 (BD-28), BRRI dhan67 (BD-67) and BRRI dhan87 (BD-87) rice plants with the formulated biofertilizer significantly enhanced their yield in both non-saline and saline conditions. Among the three rice varieties, BD-28 showed the highest significant (p<0.05) yield increase, with 104.20% under normal conditions and 3080.56% under salt stress. BD-67 exhibited a 45.15% increase in normal conditions and 153.64% under salt stress (P<0.05). BD-87 showed a significant yield increase only under salt stress, at 293.63% (p<0.05). From the results of the study, it can be proposed that the formulated biofertilizer is a potential eco-friendly and cost-effective solution to improve cultivation and yield of rice in the highly saline coastal regions of Bangladesh. Bioresearch Commu. 10(2): 1474-1481, 2024 (July)

Morphological and molecular identification of fungi isolated from selected brri rice varieties

A total of 19 fungal species were isolated from the seeds of selected rice varieties (BRRI dhan 90 to BRRI dhan 99) following Tissue planting method and Blotter method. The isolated fungi were Aspergillus niger, A. ochraceus, A. oryzae, A. tamarii, A. terreus, Chaetomium globosum, Cladosporium oxysporum, Colletotrichum gloeosporioides, Corynespora cassiicola, Curvularia lunata, Curvularia soli, Daldinia eschscholtzii, Fusarium solani, Penicillium oxalicum,Penicillium sclerotiorum, Pestalotiopsis guepinii, Pyricularia oryzae and Rhizopus stolonifer. Fourteen fungi were selected for molecular identification. Out of the 19 fungal isolates, 14 were confirmed up to species level through ITS sequence based molecular analysis. Among the isolated fungi Pnicillium sclerotiorum and Curvularia soli are the new record for Bangladesh. Association of Daldinia eschscholtzii with rice seeds is also recorded first time from world. Bangladesh J. Plant Taxon. 31(1): 73-82, 2024 (June)

Effect of Varying Level of Nitrogen and Spacing on the Yield of Boro Rice Cv. BRRI Dhan47

Effect of Varying Level of Nitrogen and Spacing on the Yield of Boro Rice Cv. BRRI Dhan47