Bangladesh Rice Journal 2019-07-20T14:18:58+00:00 Dr Md Shahjahan Kabir Open Journal Systems Official journal of Bangladesh Rice Research Institute (BRRI). Full text articles available. Seed Germination and Grain Quality of Rice as Affected by False Smut Disease 2019-07-20T14:18:58+00:00 B Nessa SS Dipti MU Salam AHMM Haque JK Biswas MA Kashem MS Kabir <p>Rice false smut (RFSm) is a disease of interest globally and in Bangladesh. Its occurrence and spread have drawn attention since 2010 in the country. While many reports are available on the yield loss from the disease, little is known of its effect on grain quality. Besides, there has been no information on how RFSm affects the seed quality with respect to germination. This study attempted evaluation of seed germination and grain quality of rice as affected by false smut disease. Three years’ study provided strong indication of inferior milling outturn and head rice yield in RFSm contaminated seeds. Results further revealed reduced amylose content and increased protein content in the contaminated seeds. Tendency in reduced seed germination, and less cooking time was observed in RFSm contaminated seeds. Future research is suggested to fully understand those causations.</p> <p>Bangladesh Rice j. 2018, 22(1): 1-7</p> 2019-06-17T06:07:52+00:00 ##submission.copyrightStatement## Effect of Seed Rate on Seedling Quality for Mechanical Rice Transplanting 2019-07-20T14:18:51+00:00 MA Hossen MM Hossain ME Haque RW Bell <p>A study was conducted in the Farm Machinery and Postharvest Technology Division, Bangladesh Rice Research Institute (BRRI), Gazipur in the irrigated dry season (Boro) of 2012-13. It was aimed at identifying the optimum seed rate of different graded rice variety for mat type seedlings preparation and suitable seedling adjustment option of the rice trans planter to maintain required number of seedlings dispensed per stroke by the rotary picker of the trans planter. Walk behind type 4-rows rice trans planter (DP 480) was used to conduct the study. The experiment was followed as two factorial completely randomized design (CRD) with three replications. Three categories of rice variety as short and bold grain (cv. BR3), medium and slender grain (cv. BRRI dhan28) and extra-long and slender grain (cv. BRRI dhan50) were considered as main factor whereas seed rate of 100, 120, 130, 140, 150 and 160g pertray (280×580×25 mm) were considered as sub-factor. Irrespective of rice category, seedling emergence decreased with the increase of seed rate. Seedling emergence decreased from 77 to 56, 74 to 57 and 77 to 54% in BR3, BRRI dhan28 and BRRI dhan29 respectively with the increase of seed rate from 100 to 160g per tray. Seed rate did not affect the seedling height significantly whereas it was varied with the rice verities only and BRRI dhan50 produced higher seedling length. However, number of leaf, stem thickness and shoot dry weight decreased and root-shoot ratio increased significantly with the increase of seed rate. The highest shoot dry weight was observed in BR3 followed by BRRI dhan50. Seedling strength also decreased with the increase of seed rate. The highest seedling strength (0.043 mg cm-1) was observed for the seed rate of 100g of BR3 and the lowest (0.020 mg cm-1) for the seed rate of 160g of BRRI dhan28. The number of seedling increased and percentage of missing hills decreased with the increase of both the seed rate and seedling adjustment option of the rice transplanter irrespective of variety. In case of BR3, seedling dispensed per stroke and percentage of missing hills varied from 4.3 to 5.7 and 6.8 to 7.8 for the seed rates of 140, 150 and 160 g of seeds tray<sup>-1</sup> for 5 to 7 seedling adjustment option of the rice transplanter respectively. Seedlings per stroke and percentage of missing hills of BRRI dhan28 for the seed rate of 130, 140 and 150 g of seeds tray-1 was found almost same for 5 to 7 seedling adjustment options of the rice transplanter (4.2 to 6.3 and 5.7 to 9.8). However, there was minimum difference of seedlings per stroke and percentage of missing hills among 120, 130 and 140 g of seeds tray<sup>-1</sup> for the option of 4 to 7 (4.0 to 5.6 and 3.9 to 7.8 respectively) for BRRI dhan50. It can be concluded that 140 g of seeds tray<sup>-1</sup> for short and bold grain (BR3) and 130 g of seeds tray<sup>-1</sup> for medium and slender grain (BRRI dhan28) under the seedling adjustment options of 5 to 7 and 120 g of seeds tray<sup>-1</sup> for extra-long and slender grain (BRRI dhan50) under the seedling adjustment options of 4 to 7 may be used for desired seedlings per hill and minimum missing hills along with good quality of seedling.</p> <p>Bangladesh Rice j. 2018, 22(1): 9-23</p> 2019-06-17T06:07:58+00:00 ##submission.copyrightStatement## Performance of Weeder in Mechanically Transplanted Rice Cultivation 2019-07-20T14:18:45+00:00 AKMS Islam MA Hossen MKA Bhuiyan MM Islam MA Rahman <p>Field performance of low land weeder was evaluated in mechanically transplanted rice fieldat Bahirbagh and Provakordi representing the silty loam soil under Gopalganj district of Bangladesh during the non-irrigated wet season (Aman) 2016. Twenty-one-day-old seedlings were transplanted by walk behind type 4-rows mechanical rice transplanter (DP480) at a pre-set spacing of 300 × 170 mm. Randomized Complete Block (RCB) design with three replications was applied with weeding practices of BRRI weeder (BW) followed by (fb) one hand weeding (HW), BRRI power weeder (BPW) fb one HW, two HW, pyrazosulfuron-ethyl (PSE) fb one HW, weedy check, weed free and mulching fb two HW (farmers’ practice) in two locations. The common weed species were observed in experimental sites. Weeding efficiency (WE) of BPW and BW was 67 and 44, respectively. Field capacity of BPW and BW was obtained 0.07 and 0.03 ha hr<sup>-1</sup>, respectively. Operator’s skill influenced the performance of weeder. During operation, BPW damaged 14-15% tillers in both the locations. However, damaged plants were revived after few days. The labour requirement in BW fb one HW, BPW fb one HW, PSE fb one HW and two HW were 380, 362, 243 and 616 man-hr ha<sup>-1</sup> respectively<strong>. </strong>Except weedy check, weed management practices showed identical grain yield in both the locations. The BCR was accounted in PSE fb one HW (1.35), BW fb one HW (1.21), BPW fb one HW (1.20) whereas the lowest BCR was observed in weedy (0.83) and two HW (1.00). It can be concluded that pyrazosulfuron-ethyl, BRRI power weeder followed by one hand weeding and BRRI weeder followed by one hand weeding appeared as the cost effective weed control methods in mechanically transplanted Aman rice production.</p> <p>Bangladesh Rice j. 2018, 22(1): 25-34</p> 2019-06-17T06:08:06+00:00 ##submission.copyrightStatement## Genetic Variability, Character Association and Path Analysis in Boro Rice (Oryza sativa L.) Germplasm from Bangladesh 2019-07-20T14:18:39+00:00 MZ Islam T Chakrabarty N Akter ESMH Rashid M Khalequzzaman MAZ Chowdhury <p>The success of varietal development programmme largely depends on the nature and magnitude of genetic variability, heritability and characters association of the crop. The objective of the present study was to estimate the extent of genetic variability and relation between yield and related characters of rice. Forty Boro rice germplasm were evaluated in a randomised complete block design with three replications. Analysis of variance indicated significant differences among the genotypes for 14 quantitative characters. The presence of slightly higher phenotypic coefficient of variation than genotypic coefficient of variation indicated the negligible influence of environment on the expression of yield and its component traits. Leaf length, days to flowering, days to maturity and 1000 grain weight showed highly positive significant correlation present with yield hill-1. High heritability had been observed for yield contributing traits during the study, suggested that these traits would respond to selection owing to their high genetic variability and transmissibility. Therefore, a thorough understanding of the inheritance of traits, their heritability and relationship with other important characteristics is important for the choice of breeding and selection methods for crop improvement.</p> <p>Bangladesh Rice j. 2018, 22(1): 35-43</p> 2019-06-17T06:08:12+00:00 ##submission.copyrightStatement## Agro-morphological Characterization and Genetic Diversity of Similar Named Aromatic Rice (Oryza sativa L.) Landraces of Bangladesh 2019-07-20T14:18:34+00:00 MZ Islam N Akter T Chakrabarty A Bhuiya MA Siddique M Khalequzzaman <p>Thirty-six similar named aromatic rice landraces of Bangladesh were studied to assess the genetic variation for the agro-morphological traits through Mahalanobis D2 statistics. The landraces were grouped into four clusters, where no duplicate landrace was found. The inter-cluster distances were higher than intra-cluster distances indicating wider genetic diversity among the landraces of different clusters. The intra-cluster distances were lower in all the cases reflecting homogeneity of the landraces within the clusters. The principal component analysis showed that the first five components with vector values &gt; 1 contributed 76.51% of the total variations. The highest number (13) of landraces was constellated in cluster III and the lowest (3) in cluster I. The intra- and inter-cluster distances were the maximum in cluster I (0.63) and between clusters I and IV (17.13), respectively and the minimum in cluster II (0.03) and between clusters III and IV (3.86), respectively. The maximum value of inter cluster distance indicated that the landraces belonging to cluster IV were far diverged from those of cluster I. So, it is expected in our results that parent’s selection for hybridization from the clusters IV and I may give the desirable heterosis for heterotic rice hybrids. Besides, the cluster mean revealed that the crosses between the genotypes of cluster I with those of clusters IV would exhibit high heterosis for maximum good characters. Hence, yield, grain breadth, days to maturity, culm diameter, ligule length had maximum contribution towards genetic divergence. Besides, evaluation of agro-morphological characters demonstrated that the aromatic rice landraces under the present study possessed a considerable genetic diversity. Therefore, similar and duplicate named aromatic rice landraces need to be conserved in Genebank for future breeding programme.</p> <p>Bangladesh Rice j. 2018, 22(1): 45-56</p> 2019-06-17T06:08:20+00:00 ##submission.copyrightStatement## Weather Condition, Seasonal Variation and Ball Development Pattern in Relation to Rice False Smut Disease in Bangladesh 2019-07-20T14:18:28+00:00 B Nessa MU Salam AHMM Haque MA Kashem MS Kabir <p>Rice false smut (RFSm) is an international disease. The effect of the disease has become seriously evident in Bangladesh since 2010. The disease is predominant in the country in the ‘T. Aman’ rice growing season. Its occurrence in other rice growing seasons not well studied and recorded. Information on driving weather variable(s) causing the disease epidemic is scanty and not ground-truthed. This study, conducted in the experimental farm of the Bangladesh Rice Research Institute, Gazipur, Bangladesh, attempted to fill those information gaps. The association of disease incidence and weather parameters such as relative humidity, cloud hour and rainfall, was inconsistence except for the daily average temperature. High disease incidence occurred when the average temperature during panicle emergence period ranged between 22-27°C; any temperature below or above the range linearly decreased the disease incidence. RFSm disease was recorded in the study area in all the months, except for in February and March. The distribution in the incidence of disease in the three rice growing seasons followed the order of ‘T. Aman’ &gt; ‘Aus’ &gt; ‘Boro’; it was ~ six times less in ‘Aus’ and ~ eight times less in ‘Boro’ season, compared to ‘T. Aman’ season. New balls formed on infected panicles in batch by batch. High number of such batches formed in ‘T. Aman’ season. The final status of the disease in an infected crop was the accumulation of incidence of the disease in each batch. This study provided key epidemiology on the development of RFSm in nature and it is concluded such information on the disease under local conditions would be the key to designing management options.</p> <p>Bangladesh Rice j. 2018, 22(1): 57-64</p> 2019-06-17T06:34:30+00:00 ##submission.copyrightStatement## Stability and Adaptability Analysis of BRRI Developed Aus Varieties in Different Locations of Bangladesh 2019-07-20T14:18:22+00:00 NMF Rahman MAA Mamun R Ahmed MI Hossain MA Qayum MA Aziz MA Hossain MS Kabir <p>The genotype by environment (G×E) interactions can be observed by differential genotypic responses to varied environmental conditions. Its effect is to limit the accuracy of yield estimates and complicate the identification of specific genotypes for specific environments. The frequently used model additive main effects and multiplicative interaction (AMMI) were used in this study to identify high yielding Aus rice varieties having wide adaptation and or specific adaptation to environment. Multi environment trials on eight Aus rice varieties were conducted at four environmental conditions in 2016. Genotype by environment (G×E) interactions contribution was much higher than the genotypic effect and environmental effect on grain yield. The genotypes BRRI dhan65, BRRI dhan48 and BRRI dhan43 display higher adaptability and stability. Therefore they are included in the study and recommended to be used in all environments. The variety BRRI dhan65 was identified as the most suitable variety with wider adaptability in the region Kushtia followed by BRRI dhan48 and BRRI dhan43. Latest varieties performed better than the oldest ones based on grain yield and could be replaced through ensuring the supply chain of new promising varieties of that locality.</p> <p>Bangladesh Rice j. 2018, 22(1): 65-72</p> 2019-06-17T06:34:37+00:00 ##submission.copyrightStatement## Effect of Irrigation Threshold on Crop Performances in Wet Seeded Rice 2019-07-20T14:18:17+00:00 S Parveen E Humphreys M Ahmed <p>Decreasing availability and increasing costs of water and labour are driving researchers and farmers to find management strategies that increase input water productivity and reduce labour requirement in rice production. Wet seeding instead of transplanting greatly reduces the labour requirement for crop establishment, whereas use of alternate wetting and drying (AWD) instead of continuous flooding reduces irrigation input. However, the safe threshold for irrigating wet seeded rice (WSR), and how this varies with growth stage, has not been established. Therefore, a greenhouse experiment was conducted to determine the effects of different degrees of irrigation threshold during different crop growth stages on crop performance of WSR. This was done in greenhouse experiment in the 2011 wet season at the International Rice Research Institute, Los Baños, Philippines. In the experiments, water stresses were applied by withholding irrigation until soil water tension increased to 10, 20 or 40 kPa at 10 cm below the soil surface. Soil water tension was measured using 30 cm long gauge tensiometer installed with the center of the ceramic cup. The stresses were applied during three crop stages: 3-leaf (3L) to panicle initiation (PI), PI to flowering (FL), and FL to physiological maturity (PM). The experiment was also included a continuously flooded (CF) treatment. Stress during 3L to PI increased the time to PI (by 2 to 4 days) but reduced the duration of grain filling by 3 to 5 days, the larger values with 20 and 40 kPa thresholds. There was no effect of stress thresholds of 10 to 40 kPa during PI-FL on crop duration. Stress during grain filling reduced the duration of grain filling by 6 days for all thresholds. Stresses of 20 and 40 kPa during 3L to PI reduced green leaf and tiller density at PI, but this effect disappeared with the imposition of CF after PI. There were consistent trends for lower final biomass as the level of water deficit stress increased, and imposition of stresses of 20 and 40 kPa at any or all three stages significantly reduced biomass compared with CF. These results suggest that, for shortening the ripening period, water stress may be imposed as 10 to 20 kPa during FL to PM.</p> <p>Bangladesh Rice j. 2018, 22(1): 73-81</p> 2019-06-17T06:34:43+00:00 ##submission.copyrightStatement## Effect of Plant Debris Removal on the Incidence of Rice Sheath Blight Disease in Bangladesh 2019-07-20T14:18:11+00:00 S Parveen MS Hossain MA Ali MA Ali <p>Sheath blight caused by <em>Rhizoctonia solani </em>is a major disease of rice (<em>Oryza sativa </em>L.) in Bangladesh that affects the crop in almost every season. The effect of floating debris removal on the incidence of sheath blight was assessed from the previously infected fields of three upazilas of Rajshahi district during T. Aman 2010. Each field was divided into two plots. Floating debris were removed from one plot while the other plot remained unremoved. Percent hill infection was higher in control plots from where floating debris were not removed (FDNR) than that of FDR plots from where floating debris were removed from the fields of Tanore, Godagari and Paba at 35 days after transplanting. The percent hill infection was 8.89% in FDR plots and 56.67% in FDNR in Tanore with a difference of 47.78%. Maximum 63.01% reduction in hill infection was found in Tanore between FDR and FDNR, whereas significant reduction in hill infection was found in Godagari (46.75%) at maximum tillering stage. The reduction in the incidence of sheath blight was 51.08% in Paba at maturity stage due to removal of floating debris from the field before transplanting. The average yield of three fields was 4.79 t ha-1 in FDR plot, whereas in FDNR, it was 4.18 t ha<sup>-1</sup> in Tanore. Thus there was an yield difference of 0.61 t ha<sup>-1</sup> in between FDR and FDNR plots. However, there was negative relationship between tiller infection and grain yield of rice. It is evident that the regression equation that the grain yield was 6.75 t ha<sup>-1</sup> in the FDNR plots when there was no infections but infection in the tillers reduced the grain yield by 0.41 unit for every unit increase in tiller infection.</p> <p>Bangladesh Rice j. 2018, 22(1): 83-90</p> 2019-06-17T06:34:50+00:00 ##submission.copyrightStatement##