BRRI Dhan29 Research Articles

Effect of Exogenous Salicylic Acid and Silicon Application on Salinity Tolerance of Rice

Soil salinity remarkably hinders rice growth, development and productivity. The present study was set up to explore the role of exogenous salicylic acid (SA) and silicon (Si) application on the growth and yield performance of two contrasting rice genotypes, namely BRRI dhan41 (salt-tolerant) and BRRI dhan49 (salt-sensitive) under salinity. The experiment was laid out in a randomized complete block design with three replications and four SA and Si treatments such as control (tap water), 100 ppm SA, 100 ppm Si (as CaSiO3) and, co-application of SA and Si (50 ppm each). Results revealed that the maximum plant height (125.2 cm), fresh weight of shoot (267.3 g) and maximum K+/Na+ (5.2) were obtained in BRRI dhan49 after sole application of Si under salt stress. Besides, the number of grains per panicle and grains per hill significantly increased in BRRI dhan41 after the sole application of SA (64 and 46%, respectively) and co-application of SA and Si (29 and 21%, respectively), and in BRRI dhan49 with sole SA (182 and 277%, respectively) and Si (75 and 446%, respectively) compared with their respective controls. Besides, we observed that the K+/Na+ was increased where the shoot accumulation of Na+ reduced significantly in both rice varieties after sole and co-application of SA and Si compared with the untreated plants. However, the present findings showed new dimensions regarding the beneficial effects of Si on rice plants which could effectively be utilized to grow and maximize rice production in the saline-prone coastal areas of Bangladesh encountering detrimental effects of salt stress on rice.
 Bangladesh Agron. J. 2022, 25(2): 119-127

Growth and Yield Response of Selected Aman Varieties as Influenced by Leaf Cutting

Sustainable crop production in the era of increasing input price is adding extra burden while the cultivable land is reducing at an alarming pace. This research article aims to test the hypothesis that the leaf cutting as an agronomic practice could be a better prospective in increasing rice grain production. An experiment was carried out in the experimental field of Sher-e-Bangla Agricultural University, to assess the effect of leaf cutting on plant growth and yield of selected BRRI released Aman varieties. The experiment consisted of five rice varieties namely BRRI dhan32, BRRI dhan33, BRRI dhan39, BRRI dhan62, and BRRI dhan56 treated either as control or leaf cutting (except flag and penultimate leaf). The experiment was laid out in randomized complete block design (RCBD) with three replicates. Leaf cutting was observed with detrimental effect on the usual plant growth and yield performances. Irrespective of all studied varieties, the highest value was obtained while no leaf cutting was performed. BRRI dhan39 was found to be the highest yield producing variety in terms of greater flag leaf length, leaf breadth, flag leaf area, required less time to grain filling, filled grain panicle-1, filled grain%, 1000-grain weight, grain yield and harvest index in leaf cutting condition followed by BRRI dhan32 in terms of plant height, chlorophyll content, tiller hill-1 and straw yield. No significant differences in yield contributing parameters except the panicle hill-1 were observed in leaf cutting condition compared to control. Leaf cutting at heading (except flag leaf and penultimate leaves) reduced average 10-20% loss of grain yield. BRRI dhan62 shown highly affected by leaf cutting compared to the rest other varieties. Therefore, it can be concluded by suggesting that leaf cutting reduces plant functional efficiency which can be improved by enhancing photosynthetic capacity through proper management of leaf architecture.
 Bangladesh Agron. J. 2022, 25(2): 1-9

Effects of Irrigation Regimes and Rice Varieties on Methane Emissions and Yield of Dry Season Rice in Bangladesh

Adoption of the right rice variety and water-saving irrigation method could reduce greenhouse gas (GHG) emissions in lowland rice cultivation. A study was conducted at the research farm of Bangladesh Agricultural University, Mymensingh, Bangladesh, in 2019 during the Boro (dry) season to determine the impacts of different rice varieties (BRRI dhan29, BRRI dhan47, BRRI dhan69, Binadhan-8, Binadhan-10, and Binadhan-17) on methane (CH4) emissions under two irrigation methods, i.e., alternate wetting and drying (AWD) and continuous flooding (CF). The treatments were laid out in a split-plot design, considering water regime as the main plots and rice variety as the sub-plots. The emission rates of CH4 were determined by collecting air samples using the closed chamber technique and measuring the concentrations using a gas chromatograph. CH4 emission rates varied with the growth and development of the rice varieties. The lowest cumulative CH4 emission rate was observed in Binadhan-17, particularly under AWD irrigation. Across the rice varieties, AWD irrigation significantly reduced the cumulative CH4 emissions by about 35% compared with CF. No significant variation in rice yield was observed between AWD (5.38 t ha−1) and CF (5.16 t ha−1). This study suggests that the cultivation of Binadhan-17 under AWD irrigation could be effective at reducing the carbon footprint of lowland rice fields.

Assessment of Yield Limiting Nutrients through Response of Rice to Nutrient Omission Technique of Shallow Brown Terrace under Madhupur Tract

A field experiment was conducted during Boro 2018-2019 and T.Aman 2019 season at Bangladesh Rice Research Institute, Gazipur to assess the yield limiting nutrients and response of rice to nutrient omission technique for the Boro-Fallow-T. Aman rice cropping pattern. The experiment was set up in a split plot design (RCBD) with three replications. Four fertilizer treatments viz T1=NPK (AEZ basis), T2=N omission (-N), T3=P omission (-P) and T4=K omission (-K) were imposed in the main plots. The rice genotypes viz Nerica Mutant, BRRI dhan28 and BRRI dhan45 in Boro season and in T.Aman BRC245-4-19-2-1, BR11 and BRRI dhan31 was laid in the subplots. Interaction of nutrient omission and rice genotypes showed significant effect on all the tested growth attributes in Boro 2018-19 season. Treatments with ample dose (NPK) show significantly outperformed than N and P omission in respect of the plant height, tiller and panicle number per square meter but no significance differences of growth attributes were observed in case of K omission in Boro season. Varietal influence of different rice genotypes due to ample dose of NPK and their omissions were insignificant but significance influence of grain yield due to nutrient omission was found. Due to P omission, highest yield reduction (80%, BRRI dhan45) was recorded in Boro season. In T.Aman Season, Only N omission significantly produced lowest tiller and panicle number per meter square. Less than 25% of yield reductions due to nutrient omission were recorded in T.Aman season. The overall findings of the study point out that the yield limiting nutrients in Boro season were identified as N and P. However, N and K was found yield limiting nutrient factor in T.Aman season.

Yield response of rice (Oryza sativa L.) to elevated potassium applied under the irrigated ecosystem of Bangladesh

A field experiment was conducted at Bangladesh Agricultural University farm, Mymensingh, Bangladesh, during the Boro season, 2017 with six different K fertilizer rates: 0, 10, 20, 30, 40 and 50 kg ha-1 to determine the optimum rate of potassium (K) fertilization for the improved yield of a specific rice variety in the irrigated ecosystem under floodplain area. Compared with no K fertilizer, adding K increased the rice grain and straw yields significantly, with all other yield contributing components, except 1000-grain weight. The highest yield of grain (7.07 ton ha-1) and straw (8.48 ton ha-1) were recorded in recommended fertilizer dose (RFD) of NPS + 50kg K treatment, which were statistically identical with RFD of NPS + 40 kg K. Rice grain and straw yields due to the different treatments increased by 18.65% to 53.74% and 18.67% to 53.78%, respectively over control. K content and uptake through grain and straw were significantly influenced by applying different levels of K. These results specified that the use of 40 kg K ha-1 had better performance on the grain and straw yields. Therefore, we conclude that the application of 40 kg K ha-1 along with the RFD of NPS for BRRI dhan29 cultivation is the best option for higher yield in Old Brahmaputra Floodplain soil.

Field Assessment of Strip-Tillage for Summer Rice Cultivation in Bangladesh

Farmers in the tropics and subtropics of Asia usually transplant rice seedlings in puddled soils which makes crop establishment and weed control easier. But rice can be grown successfully by planting into non-puddled soils after a single shallow pass of strip tillage. This method was globally reported to produce the same yield of rice as traditional puddle farming and saved labor, fuel and water, too. With this aim to asses the effect of strip tillage in the productivity of rice in Bangladesh, a trial was done at a farmer's field in the Gauriopur area of Mymensingh district in Bangladesh from July to December 2014. The productivity of four summer rice varieties, BR11, BRRI dhan46, BRRI dhan52, and BINA Dhan-7, was compared under strip tillage (ST) vs. conventional tillage (CT). The CT had two main ploughings done by a two-wheel tractor, and the ST was done in a single pass by a Versatile Multi-crop Planter. The interactive results of study showed that, except for the number of effective tillers per m2, grain yield, and BCR, none of the other parameters changed significantly between the treatments. The highest BCR profit came from BR 11 grown under ST, followed by BRRI dhan52, BRRI dhan46, and BINA Dhan-7 grown under ST. The lowest BCR was measured from BINA Dhan-7 grown under CT. This could be because the highest and lowest amount of effective and sterile tillers and the maximum grain yield were seen in the respective treatments. The ST had a 26% higher BCR than the CT, which could have been due to the 3% higher grain yield that came from having 6% more effective tillers and 42% lower sterile tillers per m2 area. In the end, we could say that ST is a more profitable way to grow rice than CT, and BR 11 is the best of the other three types.

Sulphur and Boron Fertilization Increased Productivity of Boro Rice (BRRI dhan28) by Increasing Pollen Fertility and Agronomic Efficiency in Calcareous Soils

Sulphur and Boron Fertilization Increased Productivity of Boro Rice (BRRI dhan28) by Increasing Pollen Fertility and Agronomic Efficiency in Calcareous Soils

Response of Sulphur and Boron on Growth, Yield Traits and Yield of Boro Rice (BRRI dhan28) at High Ganges River Floodplain of Bangladesh

Response of Sulphur and Boron on Growth, Yield Traits and Yield of Boro Rice (BRRI dhan28) at High Ganges River Floodplain of Bangladesh

BRRI Dhan102: An Irrigated Ecosystem-Friendly Zinc-Enriched Rice Variety for Bangladesh

An enhancement over already available zinc-enriched rice varieties for Bangladesh is the recently announced by BRRI dhan102 class of rice, which has long slender grain and is high yielding and ideal for Bangladesh's irrigated ecology. The variety has satisfactorily passed the Proposed Variety Trial (PVT) conducted in the farmers’ field in Boro 2020-21 season. As a result, National Seed Board (NSB) approved this variety for commercial cultivation in the Boro season (dry season) in 2022. It was modern plant type with 103 cm plant height and matures by 150 days. The proposed variety showed 0.27 t/ha higher yield than check variety BRRI dhan29. Identifying characters of this variety are green leaf, intermediate plant height, erect flag leaf, long slender grain, and intermediate leaf senescence grain. In average, it can produce 8.10 t/ha grain yield, but it has potentiality to give 9.55 t/ha grain yield. Thousand grain weight of the variety is 22.7 gm and head rice yield is 62%. The rice has zinc content 25.5 mg/kg, 28% amylose content with 7.5% protein content. Farmers can be benefited financially from growing the zinc-enriched variety BRRI dhan102 and the nation as a whole will be benefited nutritionally from its production throughout the Boro season (dry season).

Improvement of Mustard-Boro-T. Aman Rice Cropping Pattern Through Replacing Crop Varieties For Tangail Region

The experiment was conducted at the farmers field of FSRD site Atia, Delduar, Tangail during two consecutive years of 2018-19 and 2019-20 to develop improved cropping pattern Mustard (var. BARI Sarisha-14) - Boro (var. BRRI dhan29) - T.Aman rice (var. BRRI dhan72) and to compare its productivity and profitability against existing cropping pattern Mustard (var. Tori-7)- Boro (var. BRRI dhan29) - T.Aman rice (var. BR 11) through changing varieties of mustard and T.Aman rice with improved management practices. The experiment was laid out in a randomized complete block design with six dispersed replications. The improved management practice produced significantly higher yield in Mustard and T. Aman rice, respectively. The result showed that mean rice equivalent yield of improved cropping pattern was 16.80 t ha-1 which was 24 % higher than existing cropping pattern (13.50 t ha-1). Besides, production efficiency, land use efficiency, harvest index and profitability of improved cropping pattern was higher than farmers’ existing pattern. The mean gross return (Tk. 279720 ha-1) and gross margin (Tk. 104073 ha-1) were higher in improved cropping pattern compared to existing farmer’s pattern with only 7.82% extra cost. The marginal benefit cost ratio (4.05) also indicated the superiority of the improved cropping pattern over the farmers’ existing pattern. Bangladesh J. Agril. Res. 46(4): 397-406, December 2021

Assessment of seedling salinity tolerance of Bangladeshi coastal rice landraces using morpho-physiological stress indices

Salt stress has detrimental effects on the growth and development of rice seedlings. In the present study we assessed salt-responsiveness of three coastal rice landraces namely Nona-morchi, Kalihytta and Nara. We conducted two factors pot trial that included five rice genotypes (three candidates coastal rice landraces, Binadhan-10 as tolerant check and BRRI dhan48 as sensitive check) against three salinity levels e.g., control (tap water), 6 and 12 dSm-1 of sodium chloride. Study revealed that, at 12 dSm-1 of salinity, Binadhan-10 showed the lowest reduction in shoot length (14.62%), shoot fresh weight (30.04%) and shoot dry weight (33.71%) which was followed by Nona-morchi, Kalihytta, Nara and BRRI dhan48. Two stress tolerance indices e.g., relative water content (RWC) and electrolyte leakage (EL), also support salt-induced responses of these five rice genotypes. At the highest level of salinity (12 dSm-1), the lowest RWC reduction was observed in Nona-morchi (8.20%) which is followed by
 Binadhan-10 (11.38%), Kalihytta (38.93%), BRRI dhan48 (36.30%) and Nara (36.51%). And, the highest EL increased in Nara (40.06%) which is followed by BRRI dhan48 (22.06%), Kalihytta (21.12%), Binadhan-10 (8.64%) and Nona-morchi (5.87%) compared with their respective controls. Importantly, photosynthetic pigments profile (chlorophyll a, chlorophyll b, total chlorophyll) were increased in Nona-morchi (24.48, 15.22 and 21.87%, respectively) and Binadhan-10 (13.75, 12.50 and 13.41%, respectively) and reduced in Kalihytta (7.89, 19.42 and 11.08%, respectively), Nara (27.76, 31.32 and 28.76%, respectively) and BRRI dhan48 (32.73, 36.97 and 34.02%, respectively) at 12 dSm-1 salinity compared with their respective controls. It is to noteworthy that at 6 dSm-1 of salt stress, shoot length significantly decreased in the sensitive check BRRI dhan48 by 23.07%, Kalihytta by 17.32% and Nara by 11.54%. While, no significant effect of 6 dSm-1 of salt stress was observed in Binadhan-10 and Nona-morchi in case of shoot length, root length, shoot fresh and dry weight, EL and RWC . Among the three coastal rice landraces, Nona-morchi found as highly tolerant and Kalihytta were found as moderately tolerant while Nara was identified as sensitive against salt stress (12 dSm-1). In the future, these identified salt tolerant rice genotypes might be the ideal resource for breeding new salt tolerant rice varietie

Effect of Plant Spacing on the Growth and Yield of Local Aman Rice Cultivar

Aims: Transplant (T) aman is occupying a major portion of rice based cropping system in Sylhet region, Bangladesh. Still majority of farmers are circled to cultivate local T. aman rice cultivars, but the overall yield is very low. Agronomic management can be a good option to boost up the yield potential of these local cultivars. This study was conducted to observe the influence of planting geometry on the yield of local aman cultivars.
 Study Design: Randomized complete block design.
 Place and Duration of Study: The experiment was conducted to find out optimum plant density of local cultivars of T. aman rice during the period from August 2017 to December 2017 at farmer’s field located at Jointapur, Sylhet.
 Methodology: The study were replicated thrice in randomized complete block design considering four rice cultivars viz. Beruin (V1), Moinasail (V2), Nagrasail (V3) and, BRRI dhan49 (Control, check variety) (V4) and four plant spacings viz. (15 × 15) cm (S1), (20 × 15) cm (S2), (20 × 20) cm (S3) and (20×25) cm (S4).
 Results: The results indicated that the highest grain yield were recorded in (2.65 t ha-1) in the variety V4, which was statistically similar with V3 (2.60 t ha-1). The highest grain yield (2.87 t ha-1) was obtained (V4 × S4) while the lowest (1.58 t ha-1) from (V1 × S1). Among the local varieties highest grain yield (2.64 t ha-1) recorded in (V3 × S4) which was statistically similar (V4 × S4).
 Conclusion: Outcomes of the study revealed that Nagrasail (V3) with (20 × 25) cm plant spacing is a promising option, and isthe best one for local T. aman cultivar cultivation in Sylhet region.

Identification of Drought Tolerant Rice (Oryza Sativa L.) Genotypes with Asian and African Backgrounds.

Drought is among the major abiotic stresses on rice production that can cause yield losses of up to 100% under severe drought conditions. Neither of the rice varieties currently grown in Burundi can withstand very low and irregular precipitation. This study identified genotypes that have putative quantitative trait loci (QTLs) associated with drought tolerance and determined their performance in the field. Two hundred and fifteen genotypes were grown in the field under both drought and irrigated conditions. Genomic deoxyribonucleic acid (DNA) was extracted from rice leaves for further genotypic screening. The results revealed the presence of the QTLs qDTY12.1, qDTY3.1, qDTY2-2_1, and qDTY1.1 in 90%, 85%, 53%, and 22% of the evaluated genotypes, respectively. The results of the phenotypic evaluation showed a significant yield reduction due to drought stress. Yield components and other agronomic traits were also negatively affected by drought. Genotypes having high yield best linear unbiased predictions (BLUPs) with two or more major QTLs for drought tolerance, including IR 108044-B-B-B-3-B-B, IR 92522-45-3-1-4, and BRRI DHAN 55 are of great interest for breeding programs to improve the drought tolerance of lines or varieties with other preferred traits.

MANAGEMENT OF INSECT PEST IN RICE SEEDBED USING A NOVEL RECTANGULAR HAND NET (RHN) FOR INSECTICIDE FREE SEEDLINGS

Insect pest first attacks rice in seedbed generally 7-9 days after sprouted seed sowing. At this early sensitive stage, traditional sweep net (round hand net) is not suitable to collect insects because it injured tender rice seedlings and its insect catching efficiency is also lower than rectangular hand net. To alleviate this problem, developed a novel rectangular hand net and evaluated the efficacy for managing insect pest in rice seedbeds. Newly developed hand net consists of a rectangular frame that includes 4 mm GI wire, and the frame length and width 50 cm and 20 cm, respectively. It also consists of a plastic pipe that length 100 cm, radious 0.75 inch, and market available white colour mosquito net, which length from the frame is 80 cm. Methods of application is rapidly walking with RHN (Fig. 2) around the seedbed (model seedbed one-meter width and length depends on land condition). After sweeping full seedbed harmful insect has been destroyed and beneficial insect released back in the same field. RHN caught maximum number of major populations YSB, rice hispa, BPH, rice leaf folder, GH, etc., and remained under control. RHN caught beneficial insect (19.60 %) compare to harmful insect pest (80.39 %). In Aus season 2022, 20 m2 area BRRI dhan48, BRRI dhan98, BRRI dhan85 seedbed tenure caught insect pest (87.78 %) and natural enemy (12.22 %). Same year T. Aman season BRRI dhan76 and BRRI dhan52 seedbed period insect pest caught (71.18%) and natural enemy (28.82 %). Both seasons conducted this experiment at BRRI, Barishal Charbadna and Sagordi farm.

Water Stress Induced Changes in Root Traits and Yield of Irrigated Rice under Subtropical Condition

The presence of water or the degree of soil saturation has a direct impact on the root development and function in rice. In this regard, a pot investigation was performed to test the response of root traits and yield components of boro (irrigated) rice. Three boro rice varieties named Binadhan-10, Hira-2 and BRRI dhan 29 were grown at four irrigation regimes, viz. continuous flooding (CF), saturation (S), 75% S and 50% S at Bangladesh Agricultural University, Mymensingh, Bangladesh, throughout the boro period of 2020–2021. The study was replicated three times by employing a completely randomized design (CRD) method. The study revealed a drastic decline in root attributes at 75% and 50% S. A significant increase in root number (RN), root length (RL), root volume (RV), total dry matter (TDM) and grain yield (GY) under S condition followed by CF was observed. Binadhan-10 exhibited the largest scores of RN (359.00), RL (1577.83 cm) and RV (8.34 cm3 hill−1) at 80 DAT under S condition. Root attributes and GY were found to be substantially and positively associated in all observations. Binadhan-10 performed best with regard to seed output (26.13 g pot−1) under S condition. S condition increased the yield of Binadhan-10 in CF, 75% S and 50% S by 4.06%, 23.72% and 46.00%, respectively.

Phenotyping for the Seedling Stage of the Drought Stress Tolerance in Rice (Oryza sativa L.)

The ever-increasing demand for rice raises the need to increase productivity by developing drought-tolerant rice varieties. Drought tolerance is a complex polygenic trait that largely depends upon plant developmental stages and showed genotype-specific variability. The experiment was conducted using drought tolerant (Binadhan-19, BRRI dhan83) and drought susceptible (BRRI dhan26, BRRI dhan48) rice genotypes at the glasshouse of Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh to characterize the seedling stage drought tolerance as well as disclose the variability of the genotypes for morphological and biochemical traits. A completely randomized design (CRD) with three replications and treatments (control and drought stress imposed by 20% PEG) was used for the experiment. Data on shoot length, root length, fresh root weight, fresh shoot weight, dry root weight, dry shoot weight, chlorophyll content (SPAD value), MDA, and H2O2 were recorded and analyzed through appropriate breeding tools. Significant variation (p<0.01) was observed for genotype, treatment, and genotype (G) × treatment (T) interactions viz., shoot length, root length, root fresh weight, shoot fresh weight, root dry weight, shoot dry weight, chlorophyll, H2O2, and MDA. Drought stress leads to a significant decrease in root and shoots growth whereas the level of H2O2 and MDA increased significantly. A greater decrease in root and shoot growth was observed in susceptible genotypes (BRRI dhan28, BRRI dhan48) compared to tolerant genotypes (BRRI dhan71, Binadhan-19). In contrast, a limited increase in H2O2 and MDA was recorded in tolerant genotypes compared to susceptible genotypes. H2O2 showed a significant positive correlation with root and shoot characteristics under control conditions, whereas H2O2 showed a significant negative correlation with chlorophyll content under drought conditions. MDA showed a significant negative correlation with most of the studied traits under well-watered conditions. Considering all of the traits at the seedling stage, the genotype Binadhan-19 is considered a drought-tolerant genotype both under well-watered and drought conditions, and this genotype was selected for further study under direct field conditions as well as for genetic improvement against drought stress.

Impact of Brown Plant Hopper (Bph) Management Training on Boro Rice Cultivation In Serajganj District

A study was conducted under the project areas of Tarash Upazila at Sirajganj district. The objectives were to assess the improvement of farmers’ knowledge and perception on different factors of BPH incidence and its management to examine the economic impact on rice and to determine the profitability of Boro rice cultivation among the different groups of farms. Out of 850 samples listed, 170 representative farmers among which 16 target, 54 trained and 100 non-trained farmers were selected respectively by stratified random sampling technique. Rice plants are affected by 20-33 major insect pests. Among them, BPH is considered as most damaging one. Eighty eight, 83 and 93% target, trained and non trained farmers reported that the project needs to continue while 100% farmers of each group reported that the project is beneficial to control BPH to increase rice production. Eighty seven, 56 and 51 % farmers of the target, trained and nontrained group used double nozzle for spraying insecticides to control BPH in their field. In boro season, 2073 kg/ha and 1209 kg/ha yield loss of BRRI dhan29 were found before and after the project, respectively. The lower yield loss was due to proper management taken by the farmers who got training and acquired sufficient knowledge for controlling BPH. The study revealed that 37% higher cost and 47% higher time is required by single nozzle sprayer than double nozzle sprayer. Therefore, farmers of all categories prefer double nozzle sprayer as it is good for health and saves money and time. They also reported that use of double nozzle sprayer is more profitable than single nozzle sprayer. Benefit cost analysis indicated that the gross return, net return and BCR were found higher in case of the target farmers and these were Tk.171107/ha, Tk.73735/ha and 1.76 respectively, but the cost of production per kg was lower (Tk.10.27) than those of the other two groups due to more knowledge gathered by the target farmers on management practices for rice production. Partial budgeting analysis indicated that the double nozzle users were more benefited by Tk 7287/ha than the single nozzle users for boro rice cultivation. Thus, after the project the farmers of all categories of the project area were socio-economically benefited learning how to use double nozzle for controlling BPH.
 Bangladesh J. Agril. Res. 46(2): 211-226, June 2021

Performance of Three Boro Rice Varieties Under Different Levels of Nitrogen Application

A field exper iment was carr ied out to study the effect of levels of nitrogen on the performance of three Boro rice varieties e.g. cv. BRRI dhan28, cv BRRI dhan29 and cv. Surjomoni. The experiment comprised four levels of nitrogen viz. 0 kg N ha-1, 60 kg N ha-1, 120 kg N ha-1 and 180 kg N ha- 1 . The experiment was laid out in a randomized complete block design with three replications. The highest grain yield (4.23 t ha-1) was obtained from cv. BRRI dhan29 because of production of the highest number of both total tillers m-2 and effective tillers m-2. BRRI dhan28 produced higher grain yield (3.39 t ha-1) compared to that of Surjomoni (3.07 t ha-1). Application of 120 kg N ha-1 produced the highest grain yield (4.23 t ha-1) because of the production of the highest number of both total tillers m- ' and effective tillers m-2 in the t reatment . Appl icat ion of 180 kg N ha-1 produced the second-highest grain yield (3.70 t ha-1) and 0 kg N ha-1 produced the lowest grain yield (2.76 t ha-1). Interaction between variety and levels of nitrogen significantly influenced all parameters studied except plant height, total tillers hill -1, effective tillers hill-1, non-effective tillers hill-1, length of panicle, number of sterile spikelets panicle-1 and 1000-grain weight. The highest grain yield (4.60 t ha-1) was obtained from BRRI dhan29 with the application of 120 kg N ha-1 and the lowest grain yield (2.40 t ha- 1 ) was obtained f rom the treatment combination of Surjomoni and 0 kg N ha-1. Rice variety BRRI dhan29 can be provided with 120 kg N ha-1 to get the highest and economic production of the crop.
 Vol. 9, No. 3, December 2022: 267-278

Grain Yield and Water Productivity of Irrigated Rice Affected by Transplanting Dates in Bangladesh

Selection of suitable transplanting window is essential for getting desired crop yield and optimizing irrigation water. This study was conducted in four different locations of Bangladesh (Gazipur, Mymensingh, Cumilla and Bogura districts) to investigate the effect of transplanting period on irrigation water productivity during irrigated rice (Boro) cultivation. Ceres-rice model incorporated in DSSAT was used to estimate rice grain yield and agronomic parameters for Boro 2016-17. Daily weather data and soil data were collected from Bangladesh Meteorological Department (BMD) and Soil Resource Development Institute (SRDI). The estimated irrigation scheduling using CROPWAT- 8.0 model was used as input to the DSSAT model. Rainfall distribution showed only about 22% (2% in winter and 20% in pre-monsoon) of annual rainfall occurred in irrigated rice growing period. Delay transplanting after 15 December, the cultivar BRRI dhan28 faced higher mean daily temperature resulted shorter life span. The increased seasonal mean temperature by 2.8ºC in Gazipur and Bogura and 2.6ºC in Mymensingh and Cumilla from 15 December to 01 March reduced growth duration by 24 days in Gazipur, Mymensingh and Bogura and by 26 days in Cumilla district. Cumilla received the maximum rainfall, however Gazipur experienced the lowest among the four study locations. The received rainfall amount increased with the advancement of transplanting date from 15 December. The increased rainfall reduced the irrigation demand of the cultivar. On the contrary, reduced growth duration due to delay transplanting decreased the grain yield. Transplanting up to 1 February produced almost similar grain yield, while irrigation demand decreased from 15 December transplanting. Water productivity showed increasing trend for late transplanting. Considering grain yield and irrigation water productivity, 15 January to 1 February transplanting were found suitable transplanting period for the study locations. Rice crop establishment within the recommended period could be optimized the grain yield and irrigation water productivity in the selected study locations. Thus, maximum coverage of rainfall can be reduced the irrigation demand. Consequently, it may help to optimize groundwater use and to arrest the groundwater mining. Bangladesh Rice J. 25 (2) : 21-30, 2021

EFFECT OF SRI AND AWD TECHNOLOGY IN COMPARISON TO TRADITIONAL METHODS ON YIELD CONTRIBUTING CHARACTERS OF RICE (ORYZA SATIVA)

The leading objective of this anticipated research is to observe the effect of System of Rice Intensification (SRI) and Alternate Wetting & Drying (AWD) on yield contributing characters of rice. The project was conducted during two Rabi seasons viz. Rabi/2017-18 and Rabi/2018-19 in 9 sites under 5 Upazilla. Rice varieties namely BRRI dhan 28 and BRRI dhan 29 were used where 148 beneficiaries were involved. Modern technology SRI (System of Rice Intensification) with Traditional system were implemented for cultivation of BRRI dhan 28 and BRRI dhan 29 in Rabi/2017-18. SRI technology yielded 6.57 cm higher plant height, 12.47 more tiller and 12.90 more effective tillers and also enhanced panicle length (4.03 cm), no. of grain per panicle (20.07), 1000 grains weight (2.80 gm) and 2.60 monds higher yield than that of traditional method. During Rabi/2018-19, technology AWD (Alternate Wetting and Drying) was used with traditional method. AWD yielded 4.73 cm higher plant height, 9.89 more tiller and 9.27 more effective tillers that were significantly higher than that of traditional method. AWD technology has increased panicle length (3.24 cm), no. of grain per panicle (24.69), 1000 grains weight (1.31 gm) and enhanced 2.21 monds higher yield than that of traditional method. SRI technology yielded 11.52% higher yield in Rabi/2017-18 and AWD technology enhanced 12.20% higher yield during Rabi/2018-19 over use of traditional technology. Modern technologies (SRI and AWD) reduced 15.36% water over use of traditional technology for rice cultivation in both seasons.