Aus Rice Research Articles

Impact of extreme cyclone events on coastal agriculture in Bangladesh

Extreme cyclone events are now occurring more frequently in Bangladesh. Bangladesh experiences severe 52 cyclones from 1960 to 2010 where, the approximate percentage of storm surge impact is 40%, the largest in the world. A severe cyclone in 1970 and 1991 caused loss of 300,000 and 200,000 lives. It is reported that 210000, 36000, and 3500 tonnes of boro rice, aus rice, and other food crops (e.g. potatoes and vegetables) were totally destroyed by 1991 cyclone. The storm surge killed huge livestock and caused loss of 100% of freshwater fish. Recently, the super cyclonic storm SIDR (2007) and AILA (2009) affected 10,000 and 300,000 people, respectively. Apart from these, cyclones NARGIS (2008) and MOHASEN (2013) are also mentionable. The crop production in the coastal regions of Bangladesh is most vulnerable by cyclones while, sea level rise by 2050 will inundate 17.7% of southern coastal areas. Tropical cyclones could become more frequent with more strength under recent climate change conditions. In this research, a new dimension of extreme weather assessment is done combining GCM and GIS technology and using tropospheric instability indices. The thermodynamic environment, vertical instability characteristics of severe cyclones are indispensable to cope with climate change conditions, and for planning, disaster management, and to reduce the risk of food insufficiency.
 Progressive Agriculture, Vol. 30, Suppl. 1: 33-41, 2019

Optimization of Zinc and Boron Doses for Cauliflower-Maize-Rice Pattern in Floodplain Soil

ABSTRACTAn experiment was replicated simultaneously at two sites of floodplain soils of Bangladesh to find out the optimum application rate of zinc and boron fertilizers for crops under cauliflower-maize-transplant aus rice pattern. Randomized complete block design with three replications was used in the experimentation. The first crop of the pattern received four zinc levels (0, 2.0, 4.0, and 6.0 kg ha−1), and three boron levels (0, 1.5, and 3.0 kg ha−1). In second crop, two additional treatments receiving 2.0 kg Zn ha−1 and 2.0 kg Zn ha−1 + 1.5 B ha−1 were added; in the third crop, another four treatments were added by further application of 2 kg Zn ha−1 in each. Other nutrients viz. N, P, K, and S were used equally at recommended rates for all plots. In such a 3-crop pattern, application of 4.0 kg Zn ha−1 and 1.5 kg B ha−1 at a time to the first crop or 2.0 kg Zn ha−1 to each of the first two crops along with 1.5 kg B ha−1 to the first crop was sufficient to achieve satisfactory yield of the crops. Considering system productivity, nutrient uptake, and protein and Zn concentrations of crops, the aforesaid doses were found promising.

Acreage Response and Price Fluctuation of Rice in Bangladesh

The aim at the study is to examine the annual price fluctuation, and acreage response of rice in Bangladesh using the time series data for the period 1981-82 to 2010-11. Acreage response was estimated within the Nerlovian Partial Adjustment Model. The study estimates the growth rate of the area, production, yield and nominal price of rice and annual fluctuation on nominal and real prices of all the three rice seasons. The study was based on secondary data. Price fluctuation of Aus rice for nominal and real price was highest (-26.6 to 46.9) and (-29.4 to 37.2) in sub-period II (1991-92 to 2000-01). The fluctuation in nominal and real price of Aman rice was also highest (-27.0 to 40.7) and (-29.7 to 29.2) in the sub-period II (1991-92 to 2000-01). The fluctuation in nominal and real Boro rice price was also highest (-48.5 to 28.5) and (-34.4 to 28.4) in the sub-period II (1991-92 to 2000-01). Growth rates of area, production, yield and nominal price of three seasons of rice were estimated by fitting exponential trend function. Growth rates of area which were significantly negative for Aus, Aman that were -4.6 percent and -0.3 percent and positive for Boro rice it was 4.5 percent over the whole period. The growth rates of yield for Aus, Aman, and Boro were increased significantly at the rate of 2.2, 1.9 and 1.9 percent respectively during the entire time period. Farmer’s field-oriented policy should be developed for high yield and stable market.

Effect of irrigation salinity on the growth and yield of two Aus rice cultivars of Bangladesh

The experiment was conducted to clarify the growth and yield response of two rice cultivars, BR55 and BR43 under salt stress. Six different concentrations of NaCl viz 50, 100, 150, 200, 250 and 300 mM and distilled water (control) were applied on the rice cultivars which were grown under pot culture condition. Growth parameters like plant height, tiller number, leaf number and leaf area were negatively affected by salinity in both cultivars. Salt stress caused a significant reduction in yield in both cultivars of rice. Growth reduction was higher in BR43 than in BR55.The reduction in yield and yield parameters were found to be lower in BR55 than those in BR43. The results obtained in the present study suggest that BR55 showed higher salt tolerance than in BR43.
 Jahangirnagar University J. Biol. Sci. 7(2): 1-12, 2018 (December)

Effect of Fertilizer Packages on Broadcast Aus Rice in Lentil-B. Aus-Blackgram Cropping Pattern in the Char Land of Pabna in Bangladesh

The experiment was conducted at Char Sadipur in the char land of Pabna during Aus rice seasons of 2014 and 2015 to determine appropriate fertilizer dose for enhancing yield of B. Aus rice var. Hashikalmi and also to increase farmers’ income in char land under High Ganges River Floodplain (AEZ-11). The experiment was laid out in a randomized complete block design with four dispersed replications. Eight fertilizer packages T1: N40P9K16S6Zn1(STB), T2: N50P9K16S6Zn1, T3: N50P11K16S6Zn1, T4: N50P9K20S6Zn1, T5: N40P11K20S6Zn1, T6: N50P11K20S6Zn1, T7: N30P7K12S4.5Zn0.75 kg ha-1 and T8: Native nutrients (control) were tested for B. Aus rice in Lentil-B. Aus- Blackgram cropping pattern. The treatment N50P11K20S6Zn1 (T6) produced maximum grain yield 2.60 t ha-1 and 2.81 t ha-1of B. Aus rice in 2014 and 2015 cropping season, respectively. The highest gross return (Tk. 61,810 ha-1 in 2014 and Tk. 72,250 ha-1 in 2015 cropping season) and gross margin (Tk. 12,214 ha-1 in 2014 and Tk. 21,550 ha-1 in 2015 cropping season) was also recorded from N50P11K20S6Zn1 (T6) and lowest from control in both the years.
 Bangladesh Agron. J. 2018, 21(1): 83-88

Genotype\u2009\xd7\u2009Environment interactions of Nagina22 rice mutants for yield traits under low phosphorus, water limited and normal irrigated conditions

Multi environment testing helps identify stable genotypes especially for adverse abiotic stress situations. In the era of climate change and multiple abiotic stresses, it becomes important to analyze stability of rice lines under both irrigated and stress conditions. Mutants are an important genetic resource which can help in revealing the basis of natural variation. We analyzed 300 EMS induced mutants of aus rice cultivar Nagina22 (N22) for their G × E interaction and stability under low phosphorus (P), water limited and irrigated conditions. Environmental effect and interaction were more significant than genotypic contribution on grain yield (GY), productive tillers (TN) and plant height (PH) under these three environmental conditions in dry season, 2010. GY and TN were more affected by low P stress than by water limited condition, but PH was not significantly different under these two stresses. Mutants G17, G209, G29, G91, G63 and G32 were stable for GY in decreasing order of stability across the three environments but G254 and G50 were stable only in low P, G17 and G45 only in water limited and G295 and G289 only in normal irrigated condition. We then selected and evaluated 3 high yielding mutants, 3 low yielding mutants and N22 for their stability and adaptability to these 3 environments in both wet and dry seasons for six years (2010–2015). The most stable lines based on the combined analysis of 12 seasons were G125 (NH210) under normal condition, G17 (NH686), G176 (NH363) and G284 (NH162) in low P condition and G176 (NH363) under water limited condition. G176 was the best considering all 3 conditions. When screened for 15 Pup1 gene-specific markers, G176 showed alleles similar to N22. While two other low-P tolerant lines G17 and G65 showed N22 similar alleles only at k-1 and k-5 but a different allele or null allele at 13 other loci. These stable mutants are a valuable resource for varietal development and to discover genes for tolerance to multiple abiotic stresses.

Genetic Diversity Analysis of 53 Indonesian Rice Genotypes using 6K Single Nucleotide Polymorphism Markers

<p>Indonesia is rich in rice genetic resources, however, only a small number has been used in variety improvement programs. This study aimed to determine the genetic diversity of Indonesian rice varieties using 6K SNP markers. The study was conducted at ICABIOGRAD for DNA isolation and IRRI for SNP marker analysis. Genetic materials were 53 rice genotypes consisting of 49 varieties and 4 check genotypes. SNP markers used were 6K loci. Results showed that among the markers analyzed, only 4,606 SNPs (76.77%) were successfully read. The SNP markers covered all twelve rice chromosomes of 945,178.27 bp. The most common allele observed was GG, whereas the least allele was TG. Dendrograms of the 53 rice varieties analyzed with 4,606 SNPs demonstrated several small groups containing genotypic mixtures between indica and japonica rice, and no groups were found to contain firmly indica or japonica type. Structure analysis (K = 2) with value of 0.8 showed that the 53 rice varieties were divided into several groups and each group consisted of 4 japonica, 2 tropical japonica, 46 indica, and 1 aus rice type, respectively. IR64 and Ciherang proved to have an indica genome, while Rojolele has japonica one. Dupa and Hawara Bunar, usually grouped into tropical japonica rice, were classified as indica type, and Hawara Bunar has perfectly 100% indica type. The results of this study indicated that rice classification (indica-japonica) which is usually classified based only on morphological characters, e.g. grain and leaf shapes, is not enough and classification based on SNP markers should be considered for that purpose.</p>

Effect of nursery seeding density, age of seedling and number of seedlings hill−1 on the performance of short duration transplanted Aus rice (cv. Parija)

The cultivar Parija is a short duration transplanted Aus rice, which can be cultivated in between Boro and transplanted Aman rice without hampering their yield. Hence, research work on proper agronomic practices warrant due attention to augment the grain yield of this cultivar. An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during April to July 2012 to examine the effect of nursery seeding density, age of seedling and number of seedlings hill−1 and their effects on the yield components and yield of short duration transplant Aus rice (cv. Parija). The experiment consisted of two nursery seeding densities viz. 40, 80 g seeds m−2, three ages of seedlings viz. 20-, 30- and 40-day old and three levels of seedlings hill−1 viz. 2, 4 and 6 seedlings hill−1. The experiment was laid out in a Randomized Complete Block Design with three replications. The results showed that the treatments 40 g seed m−2 × 30-day old seedlings × 4 seedlings hill−1 individually had significant effect on the total tillers hill−1, effective tillers hill−1, grains panicle−1 and sterility percentage. In consequence, the highest grain yields of 3.28, 3.35 and 3.5 t ha−1 were found at 40 g seed m−2, 30-day old seedlings and 4 seedlings hill−1, respectively. In case of interaction the highest grain yield (4.22 t ha−1) was found in 40 g seed m−2 × 30-day old seedlings × 4 seedlings hill−1 which was at par with the interaction of 40 g seed m−2 × 30-day old seedlings × 6 seedlings hill−1 (3.84 t ha−1) and 80 g seed m−2 × 30-day old seedlings × 4 seedlings hill−1. Considering both the individual and cumulative significant effects of the treatments on the yield components and grain yield, the use of 40 g seed m−2, 30-day-old seedlings and 4 seedlings hill−1 could improve the yield components and grain yield of short duration transplanted Aus rice (cv. Parija). Therefore, short duration transplanted Aus rice (cv. Parija) can be cultivated maintaining a nursery seeding density of 40 g seed m−2 and 30-day old seedlings with 4 seedlings hill−1 for obtaining maximum grain yield.J. Bangladesh Agril. Univ. 16(2): 215-220, August 2018

DNA Fingerprinting and Genetic Diversity in Aus Rice (Oryza sativa L.) Landraces of Bangladesh

The allelic diversity and relationships among 48 Aus rice landraces were determined through DNA fingerprinting using microsatellite (SSR) markers. A total of 14 SSR markers for different chromosomes were used to characterize and differentiate the studied rice genotypes. The number of alleles per locus varied from three alleles (RM118) to 18 alleles (RM44) with an average of 9.88. The polymorphic information content (PIC) varied widely among the loci and ranged from 0.3725 (RM107) to 0.9146 (RM519) with an average of 0.7248. The genetic distance-based results found in the UPGMA clustering system revealed six genetic groups with a similarity coefficient of 0.35. Chakila and Shitki saitta had closest distance in the SSR based genetic distance might have same genetic background. Based on genetic coefficient, the diverse landraces Kasalot, Balam, Pankhiraj, Dular, Hashikalmi, Galong, Panbira, Marichbati, Pidi and Surjomoni could be selected as potential parents for varietal improvement programme. The findings of this study should be useful for varietal identification and could be useful for plant breeders in selecting suitable genetically diverse parents for the crossing programmeBangladesh Rice j. 2017, 21(1): 59-65

Genetic Diversity in Aus rice (Oryza sativa L.) Genotypes of Bangladesh

Genetic diversity in 31 traditional Bangladeshi Aus rice genotypes were studied under transplanted condition through Mahalanobis D2 statistic for grain yield and yield contributing characters. The genotypes were grouped into five clusters. The inter-cluster distances were higher than intra-cluster distances indicating wider genetic diversity among the genotypes of different clusters. The intra-cluster distances were lower in all the cases reflecting homogeneity of the genotypes within the clusters. The cluster II contained the highest number of genotypes (08) and the cluster I and III contained the lowest (05). The highest intra-cluster distance was noticed for the cluster II and the lowest for cluster IV. The highest inter-cluster distance was observed between cluster II and V followed by cluster III and V, cluster I and V and the lowest between cluster I and III. Regarding inter-cluster distance, the genotypes of cluster V showed high genetic distance from all other clusters. The genotypes from cluster V could be hybridized with the genotypes of other characters of other clusters for producing transgressive segregants. The highest cluster means for yield, effective tiller number and grain length, were obtained from cluster I; whereas the lowest mean value for yield, culm length, plant height and grain breadth were found in cluster II. Therefore, genotypes under cluster I, cluster II and cluster V might be selected for future breeding program as parents for crossing to produce new recombinants with desired traits.Bangladesh J. Agril. Res. 43(2): 253-266, June 2018

Effect of Spacing and Seedling Per Hill on the Performance of Aus Rice var. BRRI dhan48

An experiment was conducted at the research field and laboratory in the Department of Crop Physiology and Ecology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, during the period of April to August, 2016 to study the effect of spacing and number of seedlings hill-1 on the yield of Aus rice var. BRRI dhan48. Four spacing’s viz. 20 cm × 10 cm, 20 cm × 15cm, 20cm × 20 cm and 20 cm × 25cm and three number of seedlings hill-1 viz. 1, 2 and 4 were included in the study. Results indicated that the highest number of total tillers hill-1 (22.86), number of effective tillers hill-1 (21.24), number of grains panicle-1 (128.79) and 1000-grain weight (23.30g) were found with 20cm × 25cm spacing. The highest plant height (104.27 cm), number of leaves plant-1 (35.80), grain yield (3.06 tha-1), straw yield (3.37 tha-1) and harvest index were obtained from 20 cm × 10 cm spacing. The highest grain yield of 2.98 t ha-1 was obtained from 4 seedlings hill-1, while the lowest 2.47 t ha-1 from 1 seedlings hill-1. The highest grain yield of 3.40 tha-1 was obtained from 20 cm × 10 cm spacing with 4 seedlings hill-1 while the lowest grain yield of 2.21 tha-1 from the wider spacing. Results of the present study revealed that 20 cm x 10 cm spacing with 4 seedlings hill-1 combination was found to be the best for obtaining maximum grain yield of Aus rice var. BRRI dhan48.Bangladesh Agron. J. 2017, 20(2): 17-26

PERFORMANCE OF AUS RICE IN DIFFERENT TILLAGE SYSTEMS AND CROP ESTABLISHMENT METHOD IN SOUTHWEST BANGLADESH

High labor wage and irrigation water scarcity are the major constraints to becoming rice production less profitable and unsustainable in Bangladesh. To address these problems, rice production needed less water and less labor consuming production technologies. In traditional rice production systems which is puddled-transplanted rice (PTR), a significant amount of water and labor are used for tillage (wet) and transplanting operations. A farmers’ participatory on-farm trial was conducted to evaluate the performance of aus rice at different tillage systems and crop establishment methods in the southern part of Bangladesh. Wet tillage (puddled systems) to dry-tillage and transplanted rice to direct dry-seeded rice (DSR) may have the potential to reduce production cost by using less labor and water, resulting in higher profit. The trial examined tillage systems (strip tillage, reduced tillage and puddling) and crop establishment methods (direct dry-seeded and transplanted) in six farmers’ fields in aus 2015. Crop established by reduced-and strip-tillage in DSR conditions reduced crop duration by 7 d compared to PTR. Grain yield (4.4-4.6 t ha-1) was similar in DSR which is established by reduced-and strip-tillage conditions and PTR; however, total production cost in DSR was 15-18% lower than the PTR. Slightly higher but significantly similar gross income was recorded in PTR than DSR, however, net profit was significantly lower in PTR and it was due to higher production cost involvement. DSR has the potentiality of similar yield to PTR and reduces production cost which increases the net profit of rice production.

The Birth of <i>Aus</i> Agriculture in the South-eastern Highlands of India – an Exploratory Synthesis

Away from the Ganges valley, the south-eastern highlands of India is recognized as the region of origin of upland or aus rice. In this narrative, we attempt to reconstruct its origin synthesizing inklings from genetics, prehistory, and anthropology, and to find out the putative paleo-ecological, environmental, and cultural context that provided the necessary impetus to it. Genetically, we uncover a highly diverse phenotypic base with unique alleles hinting at an independent origin of aus perhaps from Oryza nivara. Post-LGM paleo-niche portrays more widely distributed O. nivara as opposed to O. rufipogon; relatively abundant O. nivara could have enabled its preferential exploitation. While a dearth of archaeological study does not illuminate much on this aspect; the agricultural attributes of the ethnic inhabitants of the area, e.g., dry rice cultivation with the hoe and the axe, reveal a striking similarity with aus or upland rice cultivation. Furthermore, comparative analyses with other historical anecdotes suggest that upland rice seems to be born as an adaptive landscape management by pre-agriculturist society. It was developed through a broader plant-people-landscape interaction, where rice or its ancestors were grown for subsistence with other crops as a Neolithic proto-agricultural package; in this case along the hill slopes. Summarizing, the current study casts light on some of the understudied aspects of upland rice agriculture, but it also brings out many open questions inviting future examination.

Growth Analysis of Short Duration Transplant Aus Rice (Oryza Sativa L. Cv. Parija) under Irrigated Ecosystem

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during April to July 2012 to examine the effect of plant spacing and nitrogen level on the growth performance of short duration transplant Aus rice (cv. Parija) under irrigated ecosystem. The experiment comprised four plants spacings viz., 20 cm × 20 cm, 20 cm × 15 cm, 20 cm × 10 cm and 15 cm × 15 cm and four nitrogen levels viz. 0, 35, 70 and 105 kg N ha-1. The experiment was laid out in a Randomized Complete Block Design with three replications. Morpho-physiological characters, of transplant Aus rice (cv. Parija) significantly influenced by spacing of planting, nitrogen level and their interaction. At 60 DAT, the highest plant height (80.68 cm) was obtained at 20 cm × 15 cm spacing fertilized with 70 kg N ha-1 which was as good as 20 cm × 10 cm fertilizad with 35 kg N ha-1. The maximum number of tillers hill-1 (15.16) was obtained at 20 cm × 20 cm spacing fertilized with 105 kg N ha-1which was statistically at par with 20 cm × 15 cmfertilized with 70 kg N ha-1. The highest total dry matter (8.92g) was obtained at the 20 cm × 15 cm spacing fertilized with higher dose of nitrogen (105 kg N ha-1) and at 45-60 DAT, the highest crop growth rate (3.34) was obtained at 15 cm × 15 cm spacing fertilized with 35 kg N ha-1 while the lowest CGR (1.12) was recorded at the same spacing (15 cm × 15 cm) with control treatment. This study revealed that short duration transplant Aus rice cv. Parija can be cultivated at 20 cm × 15 cm or 15 cm × 15 cm spacing with 35 to 105 kg N ha-1 for proper growth.

Impact of urea price change on the economic optimum level of N fertilizer use in HYV rice and its yield in Bangladesh

The study estimates the impact of change in urea price on the economic optimum level of N fertilizer use in HYV rice and its yield in Bangladesh using a large set of experimental data of BRRIfrom 15 regions covering an 11 year period (2001–2011). Results revealed that the level of N fertilizer usedin experiments to increase HYV rice yield was far lower than the economic optimum level in Aman and Boro seasonsbut higher in Aus season. The discrepancy was highest for HYV Boro rice closely followed by HYV Aman rice. Simulation exercise revealed that an increase in real price of urea by 50% will exert a 4% reduction in optimum dose of N fertilizer in HYV Amanrice and reduce yield by 101.2 kg/ha which issubstantial. The corresponding effect on HYV Bororice is relatively lowerand negligible for HYV Aus rice. The result highlights the dilemma and the detrimental effect of urea price increase on the yield ofHYV Aman rice which is the main source of foodgrain supply for the nation. Therefore, price policy should be geared towards controlling relative price of urea which can be met by a combination of subsidizing urea price and/or improving rice price.

Government input support on Aus rice production in Bangladesh: impact on farmers\u2019 food security and poverty situation

BackgroundAus rice began to lose its importance as farmers slowly started shifting to cultivation of irrigated Boro rice encouraged by its higher yields. The government of Bangladesh has launched an incentive programme for small and marginal farmers with an attempt to rejuvenate Aus rice cultivation. The aim of this study is to assess the impact of government input support on Aus rice production in Bangladesh and its impact on food security and farmers’ poverty situation. A total of 120 (i.e., 60 supported and 60 non-supported) farmers from two upazilas of Mymensingh district were selected. Data were analysed with a combination of descriptive statistics, mathematical and statistical techniques.ResultsThe results show that rice cultivation occupied the major portion of farmers’ total cropped area. The government of Bangladesh had provided with input (both cash and kind) support in order to boost Aus rice (UFSHI and NERICA variety) production. Cropping intensity of supported farmers’ was increased by 39.7%, whereas it was increased by only 1.4% for non-supported farmers. Productivity of Aus rice was 138.0 and 100.0% in stare of supported and non-supported farmers, respectively. Average per capita daily calorie intake of the households was still below the national average level of 2122 kcal. Poverty in terms of deprivation of health education, employment, housing, mobility and income was decreased, and overall livelihood circumstances were improved through government input support on Aus rice production.ConclusionsThe study concludes that the motivation provided with by the government through input support on Aus rice production was highly appreciated by the farmers. Though per capita daily calorie intake by the farmers was still under the national average level, supported farmers were more food secure than non-supported farmers. Several dimensions of poverty were decreased, and overall socioeconomic status was improved. The study recommended that scientific and technical training programmes should be arranged to raise farmers’ awareness about Aus rice production for enhancing their livelihood.

Yield Response of Direct Seeded <i>Aus</i> Rice Varieties under Rainfed Condition

Rainfed Aus rice is a popular conventional rice cultivation technique that through appropriate variety selection can accelerate the benefits of the farmer. On this context, an experiment was carried out at the research field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur1706 from April to August in 2014 to evaluate yield performance of some Aus rice varieties under rainfed condition. The experiment was laid out in a split plot design with three replications. The experiment consisted of two sets of treatments: water regime as irrigated (irrigation when necessary) and rainfed (dependent on rainfall) in the main plot and 15 varieties into sub-plots. It was revealed that yield and yield contributing characters were significantly influenced by water regime, variety and their interaction. The traits like number of effective tillers and non-effective tillers·hill-1, number of filled grains and unfilled grains panicle-1, panicle length, test weight, grain yield and harvest index were higher in irrigated crops compared to rainfed. Considering the performance of yield, the highest grain yield recorded in BRRI dhan27 (irrigated-2.47 t·ha-1 and rainfed-2.26 t·ha-1) followed by BRRI dhan55 (irrigated-1.95 t·ha-1 and rainfed-1.88 t·ha-1), BRRI dhan48 and BRRI dhan43 under both irrigated and rainfed treatment. BRRI dhan27 ranked the top under both irrigated and rainfed conditions, however the relative yield was maximum in BRRI dhan55 (reduction was only 3.59%) followed by Nerica10. Hence, considering the yield stability and absolute yield performance, BRRI dhan27 may be considered favorably cultivable for Aus season in Bangladesh followed by BRRI dhan55, BRRI dhan48 and BRRI dhan43.

Effect of bioslurry on transplanted aus rice under rainfed condition in Sylhet

An experiment was conducted in farmer’s field with the aim to evaluate the effect of integrated use of bioslurry and inorganic fertilizer on the agroeconomic performance of transplanted aus rice (t. aus) (cv. BRRIdhan42) in AEZ 20. The trial was laid out in a randomized complete block design with three replications. There were three treatments viz., T1: soil test based inorganic fertilizer dose for high yield goal (HYG), T2: cowdung (CD) slurry @ 5 t ha-1 with integrated plant nutrition system (IPNS) basis inorganic fertilizer dose for HYG and T3: Farmer’s practice (average of 20 farmers fertilizer dose). The highest mean grain yield (3.93 t ha-1) of t. aus rice was obtained from the treatment T2 followed by T1 (3.46 t ha-1). Gross return, gross margin and benefit cost ratio were also observed higher in T2. Therefore, fertilizer package NPKSZn @ 56-4-20-9-1 kg ha-1 + cow dung slurry @ 5 t ha-1 in IPNS approach might be helpful for getting higher grain yield of t. aus rice and maintaining sustainable soil health as well.Bangladesh J. Agril. Res. 42(3): 467-474, September 2017

Genetic Diversity in Aus Rice Genotypes using ILP Markers

Assessment of genetic diversity is essential for germplasm characterization, utilization and conservation. Genetic diversity of 31 Aus rice genotypes of Bangladesh was assessed using 11 ILP (intron length polymorphism) markers. A total of 28 alleles were detected and the number of alleles per locus varied from 2 (RI01779, RI05751, RI05304, RI03205, RI00299, RI05407) to 4 (RI05559). The PIC values ranged from 0.06 (RI05407) to 0.57 (RI05559) with an average of 0.33. PIC value revealed that RI05559 was the best ILP markers for the studied 31 Aus rice genotypes. The dendrogram from unweighted pair-group method with arithmetic average clustering classified the genotypes into five groups at a coefficient of 0.57. Two dimensional graphical views of Principal Coordinate Analysis (PCoA) revealed that the genotypes Kuchmuch, Kalo dhan, Aus dhan, Sadey aus, Chaina and Dighi bawalia were found far away from the centroid of the cluster and can be seslected as parents for further breeding programmes. Parangi and V3, Adubali and H1-2, Begunbichi and Hashikalmi had closest distance (0.000) in the distance matrix might have same genetic background. This information will be useful for the selection of genetically diversed parents and assist in trait development using genotypes in rice breeding programmes in future. The results provided some useful implications for establishment of sovereignty of Bangladeshi rice gene pool. It was also suggested that ILP markers could be very useful for the genetic study and breeding in rice.Bangladesh Rice j. 2016, 20(2): 13-19

Evaluation of Aus Rice (<i>Oryza sativa</i> L.) Production in Less Irrigated Situation in Northern Region of Bangladesh

Twenty one demonstrations and two validation trials were carried out at the farmers’ field in the northern region of Bangladesh during 2014 using Aus rice: variety BRRI dhan48 to enhance Aus (pre-monsoon) rice cultivation. Grain yields of 3.5 to 6.5 t ha-1 were obtained from demonstrations plots conducted in different farmers’ field. The validation trial was conducted in the farmers’ field at Mithapukur and Nilphamari Sadar Upazillas using BRRI dhan28 and BRRI dhan48 as Braus (rice grown between Boro and Aus season) after harvesting potato. Grain yield of about 5.0 t ha-1 was obtained from the rice variety BRRI dhan28, while 6.6 t ha-1 was obtained from BRRI dhan48. BRRI dhan48, due to its shorter growth duration (100-105 days) required 2-3 less irrigations. About 28-36% less irrigation water was required during dry season when BRRI dhan48 was used as Braus instead of BRRI dhan28 as a Boro crop. About 20 to 60% higher grain yield was observed in different farmers’ field with BRRI dhan48 over BRRI dhan28, which indicated that BRRI dhan48 is a potential rice variety during Aus or Braus season. BRRI dhan48 can be cultivated after Boro harvest or as Braus after potato harvest. The variety could also decrease the pressure on ground water utilization for rice cultivation during dry season. The Agriculturists 2017; 15(1) 110-115