A field experiment was conducted at the Bangladesh Agricultural University (BAU) to find out possible effects of alternate wetting and drying irrigation (AWDI) on the yield, water use and water use efficiency (WUE) of Boro rice. The experimental layout was furnitured using split-plot design (SPD) with two modern varieties (MV) of rice viz. BRRIdhan 28 and BRRIdhan 29, which received four irrigation treatments randomly and was replicated thrice. The treatments ranged from continuous submergence (T 1 ) of the field to a number of delayed irrigations (T 2 , T 3 and T 4 ) denoting application of 5 cm irrigation water when water level in the perforated PVC pipe fell 10, 20 and 30 cm below ground level (G.L.), respectively. The study revealed that treatment T 1 attributed by the highest total water use (122.2 cm) and the lowest WUE (58.53 kg/ha/cm) produced the highest grain yield (6.86 t/ha). Treatment T 2 , on the contrary, gave the second highest yield (6.58 t/ha) and consequently the second highest WUE (69.48 kg/ha/cm) indicating quite a large water saving (15 cm) compared to treatment T 1 . The yields in treatments T 3 (6.27 t/ha) and T 4 (5.86 t/ha) were significantly lower at 1% level of significance compared to that of treatment T 1 . No significant effect was found either for the treatment or for the varieties on the number of effective and total tillers hill -1 nor did they affect 1000 grain weight. Reduced plant height, no. of effective tillers hill -1 , grain yield, straw yield, biological yield and harvest index were found with the increasing water stress.

Abstract:In order to understand the present status of hatcheries, questionnaire interview and participatory rural appraisal tools were used in North-west Fisheries Extension Project (NFEP), Parbatipur during the period from July to December 2015. There are two hatcheries in NFEP, Parbatipur-a carp hatchery and a prawn hatchery. The production of spawn was around 611 kg in the year 2015. According to the target hatchery manager collected brood fish from rivers and other sources which he maintained in their brood stock ponds with proper management. The hatchery manager maintained proper age and weight of broods for spawning and followed the guideline of hatchery operation so that the quality of spawn and fry were good. It was found that the hatcheries produced fish seed of a variety of species such as Indian major carps, carpio, sarpunti, silver carp, grass carp, magur, shing as well as freshwater prawn. The hatchery production activities took place starting from February and continued up to September. The quantity of fish seed produce varied from 25 to 75 kg per hatching cycle depending on size and facilities of hatcheries. The price of fry in NFEP was being fixed by the hatchery manager. However, the price variation was seen due to seasonal variation, species and demand. The average price of fish seed was highest in monsoon and lowest in winter. A number of middlemen were involved in the fry marketing channel of NFEP at Parbatipur. They were responsible for increasing the price of fry at each stage of marketing channel.

A lead-resistant bacterial strain was isolated from coal mine dump and identified as Acinetobacter junii Pb1 on basis of 16S rRNA (ribosomal ribonucleic acid) gene sequencing. The minimum inhibitory concentration of lead for the strain was 16,000 mg l and it showed antibiotic and multi metal resistance. In aqueous culture, at an initial lead (Pb(II)) concentration of 100 and 500 mg l, lead adsorption and accumulation by the isolate was 100 and 60%, at pH 7 at 30 °C after 48 and 120 h, respectively. The two fractions of exopolysaccharide (EPS), loosely associated EPS (laEPS) and bound EPS (bEPS), and whole cells (devoid of EPS) showed high binding affinity towards Pb(II). The binding affinity of laEPS towards Pb(II) (1071 mg Pb g) was three times higher than that of bEPS (321.5 mg Pb g) and 6.5 times higher than that of whole cells (165 mg Pb g). The binding affinity of EPS and whole cells with Pb(II), reported in the current study, is considerably higher as compared to that reported in the literature, till date. SEM analysis, showed an increase in thickness of cells on exposure to Pb(II) and TEM analysis, revealed its accumulation (interior of cell) and its adsorption (with the external cell surface). The isolate was also found to be positive for indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase production which helps in promoting plant growth. Thus, this study provides a new understanding towards Pb(II) uptake by A. junii Pb1, highlighting its potential on the restoration of Pb(II) contaminated repositories.

Abstract:The present study was concerned to assess the present status of biodiversity in the Bhairab river, Jessore with its conservation measures. The study was based on primary observations, questionnaire interviews with 50 fishers, focus group discussions with river bank community members and cross-check interviews with key informants. The study was conducted for a period four months from May to August, 2016. The objective of the study was to assess the fish biodiversity in the Bhairab river, understand the existing fishing practices of the river and to identify proper management strategies for the conservation of fish biodiversity. Results of the study revealed that three kinds of fishers were engaged in the Bhairab river namely, professional fishers; seasonal fishers and subsistence fishers. Seven types of fishing gears like seine net, gill net, cast net, push net, lift net, trap and hook and line were operated to fish by the fishers during the survey. A total of 39 species of fish were identified in the catches of the Bhairab River. There are degraded ecosystems and declining biodiversity have found during the study. According to survey, fishing pressure and over fishing were responsible for almost 38% loss and pollution and siltation caused about 27% loss of ecosystem. Around 21% and 14% loss of ecosystem were caused by urbanization and human encroachment, and the recreational activities respectively. These have been created a great impact on river ecology. As a result, the water quality is deteriorating day by day and the availability of fish species and other aquatic biodiversity is decreasing gradually. During the survey, 20 species was found at a risk of being endangered. From the survey, it was found that the overexploitation of fish was responsible for the 40% losses of biodiversity in the Bhairab River and water pollution caused 35% loss of biodiversity. Henceforth, river course change and habitat degradation resulted in 15% and 10% loss of biodiversity of the river respectively. This study was identified possible ways to achieve a rich fish biodiversity in the Bhairab River with social, economic and environmental aspects. The specific recommendations are included community based fisheries management, establishment of sanctuary, control of pollution, maintenance of fishing gears and the implementation of fish act for conservation of fish biodiversity of the Bhairab River.

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