BRRI Dhan29 Research Articles

Cassava Leaf Compost Influences Growth, Yield and Nutrient Uptake of Rice

The application of compost as alternatives to reduce the use of synthetic fertilizers is considered a feasible agricultural practice to mitigate soil degradation caused by long term application of synthetic fertilizers. Therefore, the study aimed to investigate the effect of cassava leaf compost on growth, yield and nutrient uptake of rice. Six treatments of two rice varieties (BRRI dhan29 and BINA dhan5) and three sources of nitrogen (Control - no nitrogen applied but residual soil N was 0.123%, urea @ 200 kg ha-1 and Cassava Leaf Compost @ 10 t ha-1) were used in this study. Cassava Leaf Compost @ 10 t ha-1 and urea @ 200 kg ha-1 significantly increased effective tillers per hill, 1000-grain weight, and grain yield were 12.84 and 13.75, 25.00 g and 24.93 g, 5.57 t ha-1 and 6.047 t ha-1, respectively. Cassava Leaf Compost @ 10 t ha-1 and urea @ 200 kg ha-1 increased N uptake in root is 0.821% and 0.756%, and the residual effect of compost increased C, N, P, K and S availability in soil for the succeeding crop in Cassava Leaf Compost @ 10 t ha-1 applied plots. Carbon and N mineralization rates were higher than control and soils receiving recommended dose of inorganic fertilizers. Our findings suggested that compost could be used as biofertilizer to improve degraded cropland soils for sustainable agriculture.

Zinc Enriched High Yielding Rice Variety BRRI dhan84 for Dry Season Rice Growing Areas of Bangladesh

A newly released zinc enriched, high yielding, slender and red pericarp grain containing rice variety BRRI dhan84, suitable for dry ecosystem (Boro season) of Bangladesh is an improvement over existing zinc enriched rice varieties for Bangladesh. The main objective of this research was to develop the of high yielding rice varieties with improved nutritional quality in term of high zinc (Zn≥24 mg/kg) in polished grain. The study was taken in 2004 by crossing between BRRIdhan29/IR68144//BRRI dhan28///BR11 and it takes near about 13 years to develop the targeted variety. After selection of one homozygous advanced line (BR7831-59-1-1-4-5-1-9-P1) the Regional Yield Trial (RYT) was conducted in Boro 2014-15 saeson and the Advanced Line Adaptive Research Trial (ALART) was evaluated at different farmers’ field in Boro 2015-16 season and different yield trials were conducted using Randomized Complete Block Desing (RCBD). The variety has satisfactorily passed the Proposed Variety Trial (PVT) conducted in the farmers’ field in Boro 2016-17 season. As a result National Seed Board (NSB) approved this variety for commercial cultivation in the dry season (Boro season) in 2017. It has modern plant type with 96 cm plant height and matures by 140 days. The salient feature of this variety is the red colored grain, earlier than check variety, the proposed variety showed higher yield than check variety BRRI dhan28. Identifying characters of this variety are dark green leaf, semi erect flag leaf, long slender and red colored grain. It can produce 6.0-6.5 t/ha grain yield. Thousand grain weight of the variety is 22.8 g and it has colored grain tip. The rice has zinc content 27.6 mg/kg, 25.9% amylose content with 9.7% protein content. BRRI dhan84 was released as a high yielding, zinc enriched rice variety to meet the nutritional (zinc) demand of the country. The zinc enriched BRRI dhan84 is a superb variety for cultivating in the dry (Boro) season and farmers can be economically benefited and the country will be nutritionally benefited by the cultivation of BRRI dhan84.

Adaptation of Promising Rice Genotypes for Broadcast Aus Season

Rice cultivation in Aus season is eco-friendly and essential for sustainable food security of Bangladesh utilizing rain water rather than extracting underground water. Four rice genotypes (BR6855-3B-12, BR6855-3B-13, BR6848-3B-12 and BR6976-2B-11-1) along with check variety BRRI dhan43 were evaluated at farmers’ field during broadcast Aus season. The objectives were to investigate the adaptability of the rice genotypes and find out promising genotype(s) for Broadcast Aus rice. The experiment was conducted at farmers’ field in eight agro-ecological zones of Bangladesh. Randomized complete block design (RCB) was used with three replications. Standard and uniform management practices were followed for all the locations. Data were taken on grain yield, days to 80% maturity, plant height, panicles m-2, 1000-grain weight, grains panicle-1, spikelet sterility (%), Phenotypic acceptance at vegetative and maturity stage, pest incidence; feedback of farmers and extension personnel. Genotypes, environments and interaction of genotypes by environments had significant effect on grain yield, yield components and agronomic parameters. Analysis of variance indicated that there were significant differences between the check (control) and improved genotypes except the genotype BR6976-2B-11-1 which was similar with the check BRRI dhan43 for all parameters. Correlation analysis was also performed to establish extent of association between yield and major yield components. Grain yield positively and significantly correlated with the agronomic parameters except spikelet sterility. Across the locations, BR6848-3B-12 produced significantly the highest grain yield (4.88 t ha-1) at Feni while the lowest grain yield (1.58 t ha-1) was obtained in BR6976-2B-11-1 followed by BRRI dhan43 (1.64 t ha-1) at Kushtia. BR6848-3B-12 showed yield advantage of 1.0 t ha-1 over the check variety BRRI dhan43 with similar growth duration (104 day). AMMI stability value, yield stability index and GGE Bi-plot model indicated that BR6855-3B-12 is the most adaptable, suitable and stable genotype for broadcast Aus rice across the locations, and finally it is released in 2017 as BRRI dhan83 for broadcast Aus season.
 Bangladesh Rice j. 2019, 23(2): 35-48

Identification of Ideal Trial Sites and Wide Adaptable T. Aus Rice Genotypes Suitable for Bangladesh

GGE biplot study is an effective tool for many crops including rice to identify mega-environments, ideal trial site and suitable genotypes for general and specific adaptation. An attempt was made to find promising T. Aus rice genotypes having suitable grain quality, better agronomic parameters and ideal test location for T. Aus rice growing areas. In this study, a total of 11 promising genotypes along with two popular cultivars BR26 and BRRI dhan48 were tested across six locations; Cumilla, Gazipur, Rajshahi, Rangpur in T. Aus 2016 and 2017 whereas Habiganj and Kushtia only in T. Aus 2017 season. From GGE biplot study, BRRI RS, Rajshahi (E8) was the most discriminating and ideal location for evaluating T. Aus rice genotypes in Bangladesh condition while BRRI RS, Cumilla 2016 (E1) showed the least discriminating ability and the least representative location. From two years combination data, BR9011-19-1-2 (G6) recorded the highest average grain yield (5.11±0.68 t ha-1) but BR9011-46-2-2 (G2) was the most stable genotype having grain yield (4.97±0.62 t ha-1) and other stable genotypes with above average yield were BR9011-67-4-1 (G5), BR9011-34-3-2 (G1), BRRI dhan48 (G13), BR9039-28-3-2 (G9) and BR9039-9-1-3 (G8) indicated that these genotypes adapted to favourable environments. BR26 (G12) was found highly variable and less stable across the test environments. In addition, agronomic trait (plant height, growth duration) and grain quality traits were also considered for suitability and wider adaptation in T. Aus growing areas in Bangladesh. BR9011-46-2-2 (G2) and BR9011-19-1-2 (G6) were the better genotypes in most of the locations but, considering all of the parameters, the newly developed rice breeding line BR9011-67-4-1 (G5) has been identified as suitable genotype to release as a new variety for sustainable T. Aus rice production in Bangladesh.
 Bangladesh Rice j. 2019, 23(2): 77-85

Agroclimatic Indices of Rice (Oryza sativa L.) Influenced by Different Planting Times

Meteorological variables have an important role in rice production. Considering this study was carried out in Aman season of 2016 at the research field of Bangladesh Rice Research Institute, Gazipur. The research was conducted in order to investigate the effects of planting time on various agrometeorological indices viz., accumulated growing degree days (GDD), heliothermal units (HTU), photo thermal units (PTU), and heat use efficiency (HUE) the yield of advanced/variety grown under different time of transplanting in the Gazipur climatic zone (AEZ, 28). The research was conducted as a split plot using randomized complete block design (RCBD) with three replications. In this research, three planting times (1st Aug, 16th Aug, and 31th Aug) and the Advanced lines/varieties BR (Bio) 9786-BC2-119-1-1, BR (Bio) 9786-BC2-132-1-3 and BRRI dhan49 (check variety) were used in the experiment. The results showed that planting time significantly affected on grain yield. Among the genotypes, BR (Bio) 9786-BC2-119-1-1 and BR (Bio) 9786-BC2-132-1-3 produced significantly higher grain yield than check variety BRRI dhan49 in all the planting times. The variety (BRRI dhan49), transplanted at the first August, took maximum calendar days (136 days) to attain different phenological stages till physiological maturity coupled with highest growing degree days (2420 degree day) for maturity, lowest heat use efficiency (2.25 kg ha-1 c-1 day-1), highest heliothermal units (15141.01 degree day hours) and lowest photothermal units (29678.81 degree day hours) resulting lower yield. Among the advanced lines the line BR (Bio) 9786-BC2-119-1-1 took higher calendar day (134 days) to attain different phenological stages till physiological maturity coupled with higher growing degree days (2393 degree day) for maturity, heat use efficiency (2.76 kg ha-1 c-1 day-1), heliothermal units (13759.75 degree day hours) and photothermal units (30112.51 degree day hours) resulting higher yield. Taken together, the results indicate that the advanced line, BR (Bio) 9786-BC2-119-1-1, could be select as a best advanced line to release as a variety due to its higher grain yield.
 Bangladesh Rice j. 2019, 23(2): 87-94

Effect of Nitrogen Rates and Leaf Clipping on Forage and Grain Yield, and Seed Quality of Transplant Aman Rice

Sustainable fodder production is difficult from limited cultivable land occupied for food grain production. This paper presents the results of the experiment designed to test the hypothesis that forage could be produced along rice grain from the same rice field. The aim of the present study was to investigate the influence of N-rates and leaf clipping on forage and grain yield; and seed quality of transplant Aman (wet season) rice. Four nitrogen (N) rates (N1=46, N2=69, N3=92 and N4=115 kg N ha-1) and four times of leaf clipping viz, C0=No leaf clipping, C1=leaf clipping at 25 DAT (Days after transplanting), C2=40 and C3=55 DAT were evaluated following split-plot design with three replications. BRRI dhan41 was used in the experiment. N rates, leaf clipping times and its interaction had significant effects on forage and grain yield, yield components and seed quality except thousand grain weight. The results revealed that forage yield increased with increasing N rates and leaf clipping times. Grain yield was higher in higher N rates and early leaf clippings, however, it was decreased in the late clipping (55 DAT). The highest mean grain yield (5.25 t ha-1) was obtained from the treatment combination of 115 kg N ha-1 (N4) and no leaf clipping (N4C0) which was statistically similar (5.18 t ha-1) to N3C0 (5.18 t ha-1), N3C1 (5.10 t ha-1) and N4C1 (5.06 t ha-1). The lowest mean grain yield (3.17 t ha-1) was obtained from N1C3. Grain yield was reduced by 3, 6 and 24% in C1, C2 and C3, respectively compared to C0 (No leaf clipping). Qualitative characters (germination and vigour index) of seed increased with increased N rates, however it decreased in the delayed leaf cuttings. Application of 92 to 115 kg N ha-1 with early leaf clipping (25 to 40 DAT) might be allowed to attain moderate forage yield, higher grain yield, and quality seed of transplant Aman rice.
 Bangladesh Rice j. 2019, 23(2): 49-57

Exogenous Glutathione-Mediated Drought Stress Tolerance in Rice (Oryza sativa L.) is Associated with Lower Oxidative Damage and Favorable Ionic Homeostasis

Drought stress is a major concern for current agriculture as it limits plant growth and yield. An experiment was conducted with a drought susceptible rice (Oryza sativa L. cv. BRRI dhan29) to explore the potential functions and possible mechanisms of exogenous glutathione (GSH)-induced drought stress tolerance. Fifteen-day-old seedlings, GSH-pretreated or non-pretreated (0.2 mM GSH for 72 h), were subjected to PEG-induced (15% polyethylene glycol 6000) drought stress for 4 days. Rice plants exposed to drought stress displayed reduced growth, which was correlated with reduced chlorophyll content, water balance, antioxidant enzymes activities and mineral contents (K+, Ca2+ and Mg2+), as evidenced by principle component analysis (PCA) and heatmap clustering. The PCA also revealed that hydrogen peroxide (H2O2) and malondialdehyde (MDA) accumulations were strongly linked with the declined growth and development of rice plants under drought stress. Importantly, pretreatment with GSH improved the growth responses of rice plants to drought stress. GSH strengthened numerous physio-biochemical processes which were coupled with increased uptake of K+, Ca2+ and Mg2+, enhanced accumulation of soluble sugars, higher activities of enzymatic and non-enzymatic antioxidants. Moreover, GSH-pretreated seedlings under drought stress conditions had lower levels of O2·− , H2O2 and MDA which indicates successful adaptation of rice seedlings to drought stress. The results of PCA strongly supported that GSH conferred drought tolerance mostly by enhancing antioxidant activities and mineral homeostasis. Collectively, our findings provide an important prospect for use of GSH in modulating drought tolerance in rice plants. Breeding strategies should therefore be undertaken to increase the GSH content of rice plants as a means to increase drought tolerance.

Growth and yield of boro rice (Oryza sativa L.) in response to crop establishment methods and varieties

Physiological attributes and yield performance of high yielding varieties (HYV) of rice cultivars need to be assessed by crop establishment methods before promoting a suitable crop establishment method in Bangladesh. We, therefore, conducted an experiment to study the effects of crop establishment methods on the growth and yield of boro rice. The experiment comprised of two factors; factor A: methods of crop establishment viz., dry direct seeding, unpuddle transplanting, alternate wetting and drying (AWD) and puddle transplanting; factor B: rice cultivars viz., BRRI dhan28, BRRI dhan58, BRRI dhan74 and BRRI hybrid dhan3. The experiment was laid out in a split-plot design with three replications where method of crop establishment was assigned to the main plot and rice cultivar was assigned to the sub plots. Data were collected at different growth stages and at harvest. From the results, it was found that growth, yield and yield contributing characters were significantly influenced by crop establishment methods. The highest leaf area index (LAI), total dry matter and grain yield were found in puddle transplanting method. The highest grain yield was obtained in puddle transplanting method due to accumulation of maximum dry matter and production of highest number of effective tillers hill-1 and grains panicle-1. Among the varieties the highest grain yield was obtain in BRRI hybrid dhan3 due to highest number of grains panicle-1 and 1000-grain weight. The highest grain yield (6.21 t ha-1) was found in puddle transplanting with BRRI dhan28, while the lowest grain yield (2.80 t ha-1) was produced in dry direct seeding with BRRI dhan28. Therefore, puddle transplanting with BRRI dhan28 might be recommended due to best physiological performance and obtaining highest grain yield of boro rice.

Effect of age of seedlings at staggered planting and nutrient management on the growth performance of aromatic fine rice (Oryza sativa L. cv. BRRI dhan38)

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during June to December 2014 with a view to finding out the effect of age of seedlings at staggered planting and nutrient management on growth of aromatic fine rice (cv. BRRI dhan38). The experiment comprised three ages of seedlings viz., 30, 45 and 60-day old and six treatment of nutrient managements viz. control (no manures and fertilizers), recommended dose of inorganic fertilizers, 50% of recommended dose of inorganic fertilizers + cowdung @ 5 t ha-1, 75% of recommended dose of inorganic fertilizers + cowdung @ 5 t ha-1, 50% of recommended dose of inorganic fertilizers + poultry manure @ 2.5 t ha-1 and 75% of recommended dose of inorganic fertilizers + poultry manure @ 2.5 t ha-1. The experiment was laid out in a randomized complete block design with three replications. The effect of age of seedlings and nutrient management and their interaction were significant on crop growth characters of aromatic fine rice. The result revealed that the highest plant height, total tiller hill-1, total dry matter production hill-1 and CGR were found when 30-day old seedlings were transplanted. Among the nutrient managements the highest growth parameters was obtain in 75% of recommended dose of inorganic fertilizers + poultry manure @ 2.5 t ha-1 due to the continuous supply of nutrients by the combination of organic and inorganic fertilizer which led to better growth in plants. In 30-day old seedlings with 75% inorganic fertilizer + poultry manure @ 2.5 t ha-1 treatment performed best in case of all growth parameters, while the lowest one was observed in 60-day old seedlings with control. Therefore, 30-day old seedlings with 75% inorganic fertilizer + poultry manure @ 2.5 t ha-1 treatment might be a promising practice in aromatic fine rice cultivation in terms of growth performance.

Evaluation of yield performance and establishment methods of drought tolerant rice genotypes under rainfed condition in drought prone areas of Bangladesh

Two field experiments were carried out at farmer’s field of Rajshahi and Chapainawabgonj under the Department of Agronomy, BINA during aman season of 2017 and 2018 consecutively to evaluate the drought tolerant rice varieties under different establishment methods in rain fed condition. First experiment (E1) was conducted to find out the performance of varieties and second experiment (E2) was to find out the suitability of method of transplanting/sowing in combination with short duration aman varieties. Different methods were as direct seeding, puddled and un-puddled transplanting and cultivars were used to cultivate BRRI dhan56, Binadhan-7, Binadhan-17 (except in second experiment) and Huttra (local cultivar). The experiment was laid out in a randomized complete block design with three replications. The recommended fertilizer doses applied for the experiment were 80 kg N ha-1, 15 kg P ha-1, 50 kg K ha-1, 20 kg S ha-1 and 2 kg Zn ha-1. Nitrogen, phosphorus, potassium, sulphur and zinc were supplied from urea, TSP, MoP, gypsum and zinc sulphate monohydrate respectively while urea was applied in three equal splits. Among the cultivar Binadhan-17 produced statistically higher grain yield (5.62 t ha-1) at Chapainawabgonj. Among methods Binadhan-7 statistically higher grain yield 5.32 t ha-1 and 5.21 t ha-1, respectively) in puddle transplanting method both Chapainawabgonj and Rajshahi region during 2017. Among the cultivar Huttra (local) produced statistically higher grain yield (5.43 t ha-1) at Chapainawabgonj. Among methods, BRRI dhan56 statistically higher grain yield 6.37 t ha-1 and 6.19 t ha-1, respectively) in puddle transplanting method bothat Rajshahi and Chapainawabgonj during 2018. Overall results indicates that BRRI dhan56, Binadhan-7, Binadhan-17 performed better in puddled transplanting, Huttra (local) in direct seeding method in drought prone region of Bangladesh.

Bio-Economics of Different Dry Direct Seeded Winter Rice Based Intercropping Systems Under Varying Fertilizer Management

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during February to June 2017 to study the feasibility of different direct seeded rice based intercropping systems under varying fertilizer management. The experiment was conducted in afactorialrandomized complete block design with three replications. Four leafy vegetables viz., gimakalmi, Indian spinach, red amaranth andjute were intercropped with dry direct seeded boro rice (cv. BRRI dhan28) following three fertilizer dose such as 100, 75 and 125% of recommended fertilizer, and sole rice was also maintained as control. Rice yield was the highest (3.87t ha-1) in sole cropping, and intercroppingresulted insignificant rice yield reduction. Although inintercropping rice yielddecreased, but increased both gross margin and benefit cost ratio (BCR) as compared to rice sole cropping. Among the vegetables, gimakalmi performed the best followed by red amaranth in terms of yield and 125% recommended fertilizer was the best fertilizer dose. Gimakalmi intercropped with rice following 125% recommended fertilizer showed the highest gross return and BCR (2.53). Therefore, vegetables like gimakalmi and red amaranth couldbe recommended as intercrop with dry direct seeded winter rice with 125% recommended fertilizer for better productivity and higher economicreturn.
 Bangladesh Agron. J. 2019, 22(2): 103-112

Effects of integrated nutrient management on performance of t. aus rice (BRRI dhan48) in old brahmaputra floodplain soil

A field experiment was conducted at Sutiakhali, Mymensingh to see the effect of integrated nutrient management on performance of T. Aus rice (BRRI dhan48) during March to July 2015 following Randomized Complete Block Design with five treatments and four replications. The treatments were T1: RD (N75 P12 K45 S9), T2: STB (N74 P11 K36 S7), T3: INM (N54 P5 K27 S5+ CD @ 5.0 t ha−1), T4: Farmer’s practice (N69 P30 K37), and T5: Control (no fertilizer). The highest values for plant height (97.35 cm), effective tillers hill-1(19.45) panicle length (23.49 cm), filled grains panicle-1 (123.7), 1000-grain weight (25.39 g), grain yield (4.823t ha-1), straw yield (8.462 t ha-1) and biological yield (13.29 t ha-1) were obtained from T3: INM. Lowest values found in T5: Control. The maximum N, P, K and S uptake by grain (35.55, 6.99, 15.20 and 3.38 kg/ha respectively) were obtained from the application of INM. The minimum N, P, K and S uptake by grain (20.08, 3.64, 8.35 and 1.74 kg/ha respectively) were found from T5: Control. Similarly, the maximum N, P, K and S uptake by straw (3.38, 5.43, 99.25 and 7.37 kg/ha respectively) were found from T3: INM. The minimum N, P, K and S uptake by straw (1.74, 2.67, 49.70 and 3.87 kg/ha respectively) were obtained from T5 (Control). Among treatments, T3 produced highest grain and straw of BRRI dhan48. Chemical fertilizers in combination with manure based on INM could be recommended for BRRI dhan48 production in aus season.   Â

Combined Effects of Nutrient Management on Nutrient Content and Uptake of Transplant Aus Rice (BRRI Dhan48)

A field experiment was conducted at Sutiakhali, Mymensingh for crop production and chemical analysis was performed at Department of soil science, Bangladesh Agricultural University, Mymensingh to see the combined effect of nutrient management on nutrient content and uptake of Transplant Aus rice (BRRI dhan48) during march to july 2015 following Randomized Complete Block Design with four replications. The treatments were T1: RD (N75 P12 K45 S9), T2: STB (N74 P11 K36 S7), T3: INM (N54 P5 K27 S5+ CD @ 5.0 t ha−1), T4: Farmer’s practice (N69 P30 K37), and T5: Control (no fertilizer). The NPKS content and uptake by BRRI dhan48 were also influenced significantly due to combined use of manure and fertilizers. The maximum N, P, K and S uptake by grain (35.55, 6.99, 15.20 and 3.38 kg/ha respectively) were obtained from the application of Integrated Nutrient Management. The minimum N, P, K and S uptake by grain (20.08, 3.64, 8.35 and 1.74 kg/ha respectively) were found from T5: Control. Similarly, The maximum N, P, K and S uptake by straw (3.38, 5.43, 99.25 and 7.37 kg/ha respectively) were found from T3: INM. The minimum N, P, K and S uptake by straw (1.74, 2.67, 49.70 and 3.87 kg/ha respectively) were obtained from T5 (Control). The performance of the treatment T3 was better than T1, T2, T4 and T5 in nutrient content and uptake of BRRI dhan48. Considering nutrient content and uptake, the application of chemical fertilizers in combination with manure based on INM could be recommended for BRRI dhan48 production in aus season.

Root Development and Anti-Oxidative Response of Rice Genotypes under Polyethylene Glycol Induced Osmotic Stress

Osmotic stress is a kind of stress which is directly or indirectly related to all other abiotic stresses. Four rice varieties namely Binadhan-11 (with SUB1 gene), BRRI dhan52 (with SUB1 gene), Binadhan-7 and BRRI dhan71 were used to study the variation in root development and anti-oxidative response under osmotic stress conditions. Osmotic stress was induced by applying polyethylene glycol (4% PEG) in hydroponic solution. Treatment was given at the panicle initiation stage and leaf samples were collected at fourteen days after treatment to estimate antioxidant response in terms of ascorbate (APX) and peroxidase (POD) enzymatic activity. Roots were destructively harvested at 16 days after the stress imposition. The tested varieties showed significant differences in antioxidant responses under the stress condition such as high APX and POD in Binadhan-11 and BRRI dhan52. Significant injury at the 4 th leaf position (the youngest leaf was the reference) was observed at 8 and 12 days after the treatment. Number of live leaves, shoot dry weight, density of second order lateral roots, number of phytomer (Pr) and total roots, number of roots at Pr2, main axis diameter at Pr1, main axis length at Pr1 varied significantly among the varieties × treatment combinations. Binadhan-11 and BRRI dhan52 showed comparatively higher osmotic stress tolerance compared to the other two varieties without SUB1 gene, viz., Binadhan-7 and BRRI dhan71. The varieties BRRI dhan52, and Binadhan-11 showed greater capacity to withstand osmotic stress can be further used to develop stress tolerant variety.

A Rice Variety (BRRI dhan29) Yield Performance as Influenced by Foliar Application of Salicylic Acid in Bangladesh

Objective of this study was to examine and evaluate the role of different rates of salicylic acid (SA) as foliar spray on growth and yield performance of BRRI dhan29. The experiment was conducted at Sher-e-Bangla Agricultural University, Bangladesh from November, 2016 to May, 2017 following a randomized complete block design with five rates of SA in six replications. The results showed that the lower rate of SA (upto 0.75 mM) has a positive effect on rice biomass production including effective tiller per hill, filled grain per panicle, grain yield and straw yield. The highest dry matter production at both maximum tillering and panicle initiation stages was found at SA spray rate of 0.5 mM. The highest number of effective tillers per hill (14.7) as well as the highest filled grain (120.4) and grain yield (8.1 t/ha) were found at SA rate of 0.75 mM. However, the maximum biomass production was obtained at SA rate of 0.25 mM. The minimum grain yield (7.0 t/ha) was observed in the control treatment.

Assessment of Different Weed Control Methods on Growth and Yield Performance of T. Aus Rice

An experiment was conducted in the Agriculture Field Laboratory, Noakhali Science and Technology University (NSTU) during the period of April-August 2019, for the assessment of different weed control methods on growth and yield performance of transplanting aus (early summer) rice. The experiment was carried out with four (4) weed control treatments viz. T1 = No weeding (control); T2 = Hand weeding at 15 and 30 DAT; T3 = Pre-emergence herbicide (Acetachlore 14% + Bensulfuron methyle 4%); T4 = Post-emergence herbicide (Pyrozosulfuran ethyle 10 %) using two aus varieties viz. BRRI dhan 83 and BRRI dhan 65. The experiment was carried out in a Randomized Complete Block Design with three replications. The result revealed pre-emergence herbicide (T3) as the most effective and efficient method of weed control by increasing yield significantly. No weeding caused 37.46 % loss of yield in this experiment where the application of pre-emergence herbicide showed 96.26 % higher yield than no weeding followed by hand weeding 79.14 % and post-emergence herbicide 64.70 %. Post-emergence herbicide performed well in tillers hill-1 along with straw yield. No weeding showed worst performance in every growth and yield attributes also it resembled as liable for maximum sterile grains panicle-1. Despite some offensive effects, no efficient alternative is currently available to shift the herbicidal weed control in aus rice as manual hand weeding is laborious and costly. Being efficient in controlling weeds, application of the pre-emergence herbicide may be used for effective weed control in aus rice.

Interactive effect of variety and potassium fertilizer on the yield of salt-tolerant Boro rice

Performance of salt-tolerant Boro rice was investigated under the interaction effect of variety and different doses of potassium fertilizer, which is a part of the research for developing agriculture in coastal areas of Bangladesh. A field experiment was conducted at the research field of Agriculture department, Noakhali Science and Technology University (NSTU), Noakhali-3814. The experiment was carried out in a Randomized Complete Block Design (RCBD) with three replications where two varieties viz. BINA dhan-8, BRRI dhan-28 and three doses of potassium viz. 120 kg/ha, 84 kg/ha and 36kg/ha were used as treatments. Plant height (cm), tillers/hill, grain/panicle, 1000 grain weight (g), grain yield (t/ha), straw yield (t/ha) and harvest index (%) were compared among varieties and treatments. Results revealed that only variety and only potassium fertilizer had non-significant influence but the interaction of variety and potassium fertilizer had a significant effect on the performance of salt-tolerant Boro rice. Therefore, the present study suggests that salt-tolerant BINA dhan-8 variety may be cultivated with 120 kg potassium/ha for obtaining higher yield in the southern coastal area of Bangladesh.
 Asian Australas. J. Biosci. Biotechnol. 2020, 5 (1), 21-26

Water management effects on irrigation cutback and yield performance of dry direct seeded boro rice

Dry direct seeding is an alternative rice production method that reduces 50-60% irrigation water required compared to the conventional method. The present study was undertaken with a view to optimize irrigation requirement for dry direct seeded rice. The experiment involved seven water management levels and two rice varieties in a split-plot design allocating water management levels in main plot and rice variety in sub-plot. The treatments were replicated thrice. The water management levels are (i) puddled transplanted rice with full irrigation (PTR-CI), (ii) puddled transplanted rice with alternate wetting and drying (AWD) irrigation (PTR-AWD), (iii) dry direct seeded rice with no standing water at all, (iv) dry direct seeding with AWD irrigation (DDSR-AWD), (v) dry direct seeded rice with 3-5 cm standing water from panicle initiation to heading, (vi) dry direct seeded rice with 3-5 cm standing water from panicle initiation to grain filling, (vii) dry direct seeded rice with 3-5 cm standing water from heading to grain filling. Two rice varieties included in the experiments are BRRI dhan28 and BRRI dhan29. The frequency and amount of irrigation for different plots were recorded. Data on different crop characters, yield and related attributes were collected and were subjected to statistical analysis using a computer package program MSTAT-C. The results reveal that rice gave the highest grain yield in dry direct seeding system where the standing water was maintained from panicle initiation stage to flowering (T5) or grain filling stage (T6) at reproductive phase. The T5 treatment required 7-9 irrigations whereas T6 required 9-12 irrigations. The treatment T5 required 50% less irrigation water than PTR-CI method. Thus, it may be concluded that dry direct seeded rice should be practiced for rice and standing water should be maintained from panicle initiation to heading for obtaining higher grain yield with least irrigation input.
 Asian Australas. J. Biosci. Biotechnol. 2020, 5 (1), 6-14

Allelopathic potential of marshpepper residues for weed management and yield of transplant Aman rice

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, during the period from June to December 2016 to evaluate the effect of marshpepper (Polygonum hydropiper L.) crop residues on weed management and crop performance of transplant aman rice. The experiment consisted of three cultivars viz. BR11, BRRI dhan33 and BRRI dhan49 and five marshpepper crop residues treatment such as 0, 1.0, 2.0, 3.0 ton ha-1 and hand weeding. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Five weed species belonging to four families infested the experimental plots. Weed population and weed dry weight were significantly affected by cultivar and crop residues treatment. The highest percent inhibition of all the studied weed was found by hand weeding. The second highest percent weed inhibition was found with the application of marshpepper residues at 3.0 t ha-1 which was 63.43, 63.43, 52.85, 52.40 and 59.12 percent for sabuj nakful (Cyperus difformis), chesra (Scirpus juncoides), shama (Echinochloa crusgalli) panikachu (Monochoria vaginalis) and panishapla (Nymphaea nouchali ) respectively. The maximum weed growth was noticed with the cultivar BRRI dhan33 variety and the minimum was found in the cultivar BRRI dhan49. The grain yield as well as the yield contributing characters produced by BRRI dhan49 was the highest among the studied varieties. The highest reduction of grain yield was obtained in no crop residue treatment. The highest number of effective tillers hill-1, number of grains panicle-1, 1000-grain weight, grain and straw yields were observed in marshpepper residues in hand weeding followed by 3.0 t ha-1 marshpepper crop residue. BRRI dhan49 produced the highest grain and straw yields under hand weeding followed by marshpepper residues 3.0 t ha-1 treatment. Results of this study indicate that marshpepper residues showed potentiality to inhibit weed growth and it has a significant effect on the yield of transplant aman rice. Therefore, marshpepper residues might be used as an alternative way for weed management effective and sustainable crop production.
 Progressive Agriculture 30 (4): 379-386, 2019

Residual effect of raw material of chitosan powder on chemical properties of soil under rice-rice cropping system

The experiment was conducted at the research field of Sher-e-Bangla Agricultural University, Dhaka- 1207, Bangladesh, during 2015-2016, to investigate residual effect of raw material of chitosan (CHT) powder on chemical properties of rice growing soils. The field experiment was done using BRRI dhan29. The experiment was laid out in randomized complete block design (RCBD) with four replications. The first experiment was done using four different doses of the raw material of CHT powder with one control. The treatments were as follows: T1= 0.5 t/ha, T2 = 1.0 t/ha, T3 = 2.0 t/ha, T4 = 4.0 t/ha and T5 = 0 t/ha. The second experiment was conducted in the same plot using the following treatments were T1= Residual effect of the raw material of CHT powder @ 0.5 t/ha (applied in the previous experiment) + 2/3rd of recommended N fertilizer, T2 = Residual effect of the raw material of CHT powder @ 1.0 t/ha (applied in the previous experiment) + 2/3rd of recommended N fertilizer, T3 = Residual effect of the raw material of CHT powder @ 2.0 t/ha (applied in the previous experiment) + 2/3rd of recommended N fertilizer, T4 = Residual effect of the raw material of CHT powder @ 4.0 t/ha (applied in the previous experiment) + 2/3rd of recommended N fertilizer and T5 = Residual effect of the raw material of CHT powder @ 0 t/ha + recommended N (control). The total nitrogen content, soil pH, organic carbon and organic matter status in the post-harvest-soils were increased due to the residual effect of the powder in rice growing soils. The maximum value of the pH (7.01), organic carbon content (0.72%), and organic matter content (1.24%) in the post-harvest soils were found in the treatment T4 and lowest values were observed in the control treatment (T5). From the results it could be concluded that some of the chemical properties of rice growing soils were improved due to the residual effect of the raw material of CHT powder. Residual nitrogen value indicates that the raw material of CHT powder has a slow releasing effect of organic nitrogen supplementation in soil. These results suggest that the residual effect of the raw material of CHT powder could play a significant role to improve the sustainable soil health.
 Res. Agric., Livest. Fish.7(1): 33-42, April 2020