Experimental investigation of the ternary Mg-Al-Sr system

In this work, the ternary Mg-Al-Sr system was investigated experimentally by differential scanning calorimeter (DSC), X-ray Diffraction (XRD) and metallography. The experimental work focused on the critical regions after reviewing the phase diagrams developed by thermodynamic modeling. DSC has permitted real-time measurement of the temperature and enthalpy of the phase transformations. The experimental results were compared with the pertinent thermodynamic findings as well as with the literature data. The thermodynamic calculations are consistent with experimental results in few samples especially in the liquidus temperature, whereas discrepancy was observed in several cases especially in the solid phase transformation temperature that suggests this system should be remodeled. Two ternary eutectic transformations have been observed. XRD was used to identify the phases in the studied samples where Al 4 Sr and (Mg) were found to be the dominating phases. Distinct unknown peaks were observed in the investigated samples. In this investigation, four new phase fields have been tentatively identified. The new phase may be ternary intermetallics or ternary or binary solid solutions. Thermodynamic calculations were also utilized to understand the microstructures and the phase relationships. The microstructural evolution in two post-DSC samples has also been investigated and compared with the as-cast condition

Agronomic manipulation for adaptation of black rice cultivars in plain land environment to eliminate hidden hunger

Two field experiemtns were conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during the period from July 2016 to December 2016 to study the effect of cultivars, date of transplanting and fertilizer dose on the yield and quality of few hilly black rice cultivars. The experiment one consisted of two factors. Factor A: Varieties, viz., i) Galong se and ii) Gelong ni and Factor B: Planting date, viz., i) July 20, ii) August 5, iii) August 20, iv) September 5, v) September 20 and vi) October 5. The experiment two also consisted with two factors. Factor A: varieties, viz., i) Kongnam ene ii) Gelong se and iii) Nazirshail rice and Factor B: Fertilizer management viz., i) No fertilizer ii) 50% of recommended dose (RD) of fertilizers of a local aman rice variety, iii) 75% of RD of fertilizers of a local aman rice variety, iv) 100% of RD of fertilizers of a local aman rice variety, v) 125% of RD of fertilizers of a local aman rice variety and vi) 150% of RD of fertilizers of a local aman rice variety. Results revealed that among varieties, the black rice cultivar Gelong se was best grain yielding potential variety than three other rice varieties, of which two are black rice cultivars (Kongnam ene and Gelong ne) and another one is plain land white rice cultivar (Nizershail). Regarding time of transplanting it has been found that all the varieties gave higher yield when they were transplanted either on July 20 or August 05. The worst transplanting time was October 5 when lowest grain yield was obtained. From the nutritional view point, it has been found that all the three black rice cultivars got higher crude protein (%), crude fibre (%), ash (%), crude fat (%), Fe (ppm) and Zn (ppm) content over white rice cultivar. Therefore, it can be concluded that black rice could be incorporated in human diet and it would be a way of eliminating hidden hunger

Growth, yield and quality of faba bean (Vicia faba L.) in response to sowing date and phosphorus fertilization

An experiment was carried out to study the effect of date of sowing and level of phosphorus on the yield, yield components and seed protein content of faba bean (Vicia faba L.) at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during November 2018 to March 2019 to study the influence of sowing date and phosphorous fertilization on the growth, yield and quality of faba bean (V. faba). Three date of sowing viz. 25 November, 5 December, 15 December and five levels of phosphorus viz., 0, 10, 20, 30, 40 kg P ha-1 were used in this experiment laid out in a randomized complete block design with three replications.  At 60 DAS, 25 November sowing fertilized with 40 kg P ha-1 showed significant influence on all characters except dry matter production. Early sowing on 25 November produced the tallest plant (42.95 cm), highest number of branches plant-1 (8.31), number of pods plant-1 (49.87), 1000-seed weight (97.55 g), seed yield (1.21 t ha-1), stover yield (1.98 t ha-1) and seed protein content (31.54%) while the corresponding lowest values were recorded from late sowing on  15 December. The crop fertilized with 40 kg P ha-1 produced the highest number of branches plant-1 (8.33), number of pods plant-1 (49.05), 1000-seed weight (97.40 g), seed yield (1.33 t ha-1), stover yield (2.28 t ha-1) and seed protein content (38.17%) while control treatment (0 kg P ha-1) produced the lowest values of all parameters. In case of interaction, the highest number of pods plant-1 (58.42), seed yield (1.59 t ha-1), stover yield (2.44 t ha-1) and protein content in seeds (39.60) were recorded with 25 November sowing fertilized with 40 kg P ha-1 whereas the lowest seed yield (0.54 t ha-1), stover yield (1.32 t ha-1) and seed protein content (25.90%) were obtained from 15 December sowing along with control treatment. Therefore, early sowing (25 November) with 40 kg P ha-1 appears as the promising combination for higher yield and seed protein content of faba bean

Weed competitiveness of winter rice (Oryza sativa L.) under modified aerobic system

The study was conducted during winter season (February-June) of 2016 at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh. Fourteen rice varieties namely, BRRI dhan28,  BRRI dhan29, BRRI dhan47, BRRI dhan50, BRRI dhan55, BRRI dhan58, BRRI dhan59, BRRI dhan67, Binadhan-5, Binadhan-6, Binadhan-8, Binadhan-10, BRRI hybriddhan3 and Agrodhan14 were grown under weedy and weed- free conditions. Plots with no rice were also maintained to study the natural growth of weed in absence of rice. Primed rice seeds were dry seeded following 25 cm ×15 cm spacing with 5 seeds hill-1 on non-puddled soil. Plots were surface irrigated as and when necessary to maintain aerobic condition (at around field capacity) up to heading stage followed by wet condition from heading to grain filling stage. The results revealed that rice varieties varied widely in yield performance and weed suppressive ability. Among varieties, BRRI dhan59 allowed the minimum weed growth (20.8 g m-2) while Binadhan-5 allowed the maximum weed growth (65.8 g m-2). Grain yield ranged from 2.2 t ha-1 (BRRI dhan55) to 4.67 t ha-1 (Binadhan-5) under weed-free condition and from 0.62 t ha-1 (BRRI dhan55) to 2.48 t ha-1 (BRRI dhan59) under weedy condition. Weed infected relative yield loss ranged from 40.1% to 78.2% among varieties. BRRI dhan59 incurred the least yield penalty (40.1%) while Binadhan-5 performed the best in terms of grain yield (4.67 t ha-1) but its weed inflicted relative yield loss was higher (76.4%) than any other variety with low yield potential. BRRI dhan59, on the other hand, appeared as the most weed competitive variety (only 40.1% relative yield loss) with yield of 4.19 t ha-1. Present study confirms that the varieties tested under study varied widely in terms of weed suppressive ability and yield performance. Considering both yield and weed competitiveness, BRRI dhan59 can be recommended for cultivation following modified aerobic system

Effectiveness of integrated weed management in five varieties of aromatic rice in Bangladesh

An experiment was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, Bangladesh to evaluate the efficacy, rice selectivity and cost-effectiveness of some integrated weed control methods on the productivity of aromatic rice under randomized complete block design with three replications. The experiment consisted of five aromatic rice varieties; Kalijira, BRRI dhan34, BRRI dhan37, BRRI dhan38 and Binadhan-13, and six different weed management practices comprising no weeding, weed free, mechanical + manual weeding, pre–emergence herbicide + manual weeding, post–emergence herbicide + manual weeding, pre– + post–emergence herbicide. Ten weed species belonging to five families infested the experimental plots. Herbicide treatments provided excellent weed control efficiency and produced much higher net benefit and cost benefit ratio than weedy plot. Among the herbicidal and mechanical treatments, sequential application of Bensulfuran methyl + Acetachlor at early growth stage (pre-emergence herbicide) followed by Pyrazosulfuran ethyl at mid growth stage (post-emergence herbicide) provided the highest weed control efficiency, productivity and net benefit. Single application of Pyrazosulfuran ethyl at mid growth stage followed by one hand weeding performed very close to the pre– + post–emergence herbicide application in terms of productivity and net benefit but in terms of weed control efficiency at 45 days after transplanting application of Bensulfuran methyl + Acetachlor at early growth stage followed by one hand weeding performed very close to pre– + post–emergence herbicide application. Mechanical weeding followed by one hand weeding and application of Bensulfuran methyl + Acetachlor at early growth stage followed by one hand weeding also provided satisfactory results in terms of productivity and economic return. Since manual weeding was less economic, sequential application of pre- and post-emergence herbicides may be recommended for effective weed management in aromatic rice

Weed suppressive ability of BRRI released popular monsoon rice varieties

Develoment of weed competitive crop cultivars is an attractive low-cost strategy of integrated weed management program that can reduce the heavy dependence of crop cultivation to chemical herbicides. Hence, to evaluate the weed competitiveness Bangladesh Rice Research Institute (BRRI) released selected monsoon rice varieties, a field experiment was conducted during July to December 2018 at the Agronomy Field Laboratory of Bangladesh Agricultural University. Thirty-three rice varieties were grown under season long weedy and weed-free conditions. Plots without rice plants were also maintained to investigate the natural growth of weed in absence of rice. The experiment was conducted following randomized complete block design with three replicates. The results showed that rice varieties varied widely in yielding ability and weed competitiveness. Among rice varieties, BRRI dhan31 allowed the minimum weed growth (32.5 g m-2) while BRRI dhan51 allowed the maximum weed growth (155.3 g m-2). Grain yield ranged between 3.6 t ha-1 (BRRI dhan49) and 7.5 t ha-1 (BR10) under weed-free condition and between 2.2 t ha-1 (BRRI dhan70) and 3.9 t ha-1 (BRRI dhan34) under weedy condition. Weed imposed relative yield loss ranged from 10.2 to 66.9% among the rice varieties. BRRI dhan34 allowed the least yield penalty (10.2%) while BRRI dhan70 had the maximum yield penalty (66.9%) due to competition with weeds. Although BR10 appear as the most productive variety (7.5 t ha-1) its weed imposed relative yield loss was higher (51.3%) than many other varieties with low yield potential. On the other hand, BRRI dhan34 appeared as the most weed competitive variety (only 10.2% relative yield loss) with productivity of 3.9 t ha-1. Considering the yield, BR10 was the best but for weed suppressive ability BRRI dhan34 performed well

Allelopathic Potential of Three Oil Enriched Plants against Seedling Growth of Common Field Crops

Current study aims to investigate into the allelopathic potential of the different parts (leaf, bark, stem, twig and root) of three oil-enrich plant species of Bangladesh viz., Jatropha curcus, Ricinus communis and Aphanamixis polystachya. The aqueous extract of those plant parts were diluted into four different concentrations viz., 1:5, 1:10, 1:15, 1:20 (w/v) and tested against the seedling growth of jute, rice, wheat, radish, tomato, mungbean and mustard under control laboratory condition. A control (distilled water without extract) was also maintained in every cases and the bioassay experiment was replicated thrice. The results of this research showed that the shoot and root growth inhibition of rice, wheat, jute, tomato, radish, mungbean and mustard by leaf, bark, stem, twig and root extracts of J. curcus, R. communis and A. polystachya varied significantly. Compare to the shoot growth, the root growth of the test species inhibited more except J. curcus. The leaf and root have higher allelopathic potential than any other parts of the studied plants. Finally, it can be concluded here that J. curcus plant extracts has higher allelopathic potential than other two plants R. communis and A. polystachya. Therefore, J. curcus can be used as a candidate plant for isolation and identification of allelopathic substances for the development of new natural herbicides

Optimizing seed rate for summer mungbean varieties

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from March to June, 2007 to investigate the effect of cultivar and seed rate on morphological characters, yield attributes and yield of summer mungbean. The experiment comprised four varieties viz., BINA moog2, BINA moog5, BINA moog6 and BINA moog7 and four seed rates viz. 30, 40, 50 and 60 kg ha-1. The experiment was laid out in a randomized complete block design with four replications. Results revealed that variety and seed rate had significant effect on the studied crop characters and yield. The variety BINA moog7 showed superiority in relation to plant height, number of branches and effective pods per plant, number of seeds pod-1 compared to other varieties, which resulted in the highest seed yield both per plant and per hectare. The plant height, stover yield and number of non-effective pods per plant increased with the increase in seed rate, while branch number, number of effective pods per plant, seeds per pod, 100-seed weight, as well as seed weight per plant decreased with increasing seed rate. The higher number of branches and effective pods per plant, number of seeds pod, 100-seed weight and seed yield per plant were recorded at the rate of 30 and 40 kg seeds ha-1 and the lowest values for the above parameters were observed at the rate of 60 kg seeds ha-1. But per unit area basis, the highest seed yield was recorded in 40 kg seeds ha-1 followed by 50 kg seeds ha-1 due to accommodation of higher number of plants. BINA moog7 interacted favorably with the seed rate of 30 kg ha-1 to produce the highest seed yield

Plant density influence on yield and nutritional quality of soyabean seed.

Plant density is an important factor affecting soybean seed yield and but information regarding plant density effects on seed quality is highly scarce. The present study examines the relationship of seed yield and quality of two soybean varieties viz., PB-1 and G-2 with plant densities. The experiments were conducted in three consecutive seasons viz., Rabi 2004-05, Kharif 2005 and Rabi 2005-06 at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh, Bangladesh. Six plant densities viz., 20, 40, 60, 80, 100 and 120 plants m -2 were established using an equidistant planting pattern having spacings of 22.4×22.4 cm, 15.8×15.8 cm, 12.9×12.9 cm, 10.0×10.0 cm and 9.1×9.1 cm, respectively. A split-plot design was used having variety as main plot and density as sub-plot with three replicates. The results revealed that soybean seed yield increased with increase of plant density and the highest yield was obtained at 80 to 100 plants m -2 depending on variety and season. The further increase in plant density reduced the seed yield. The seed yield, seed protein and mineral contents such as phosphorus, calcium, potassium, sulphur and zinc showed a quadratic relation with plant density. Seed protein content decreased with increase in plant density up to 80 or 100 plants m -2 and then increased with further increase in plant density while reverse occurred for seed yield and different minerals. The results also showed that seed protein content was inversely related with seed yield and mineral contents in seed

Effects of sea water and herbicide for salt toelarnt weed mangement in turfgrass

Sea water in combination with trifloxysulfuron-sodium and quinclorac were used to observe weed injury level in turfgrass field. The weed species viz., Sporobolus diander (L.) R. Br., Croton aromaticus L., Croton rotundus and Emilia sonchifolia (L.) DC. ex Wight except Emilia atrovirens were fully controlled when treated with 3/4 recommended trifloxysulfuron-sodium with sea water, 3/4 recommended trifloxysulfuronsodium with 3/4 sea water, 1/2 recommended trifloxysulfuron-sodium with sea water, 3/4 recommended quinclorac with sea water and 3/4 recommended quinclorac with 3/4 sea water. Eragrostis atrovirens (Desf.) Trin. ex Steud. exposed maximum (48%) injury when treated with 3/4 recommended trifloxysulfuron-sodium and sea water. Paspalum vaginatum Sw. showed only 8% injury to sea water in combination with 3/4 recommended quinclorac, indicating greater salt tolerance among the three turfgrass. Zoysia japonica Steud. also exposed no more than 14% injury when treated with sea water in combination with 3/4 recommended trifloxysulfuron-sodium or quinclorac. Cynodon dactylon (L.) Pers. 'Satiri' had up to 21% salt injury with 3/4 sea water in combination with 3/4 recommended trifloxysulfuron-sodium