Annals of Bangladesh Agriculture

Spatiotemporal dynamics of land use and cropping systems in the young meghna estuarine floodplain

2024-01-09T04:54:51+00:00

To explore long-term changes in land use and land cover (LULC), cropping systems, and driving forces of LULC change, a study was carried out in Subarnachar upazila under the Young Meghna Estuarine Floodplain in Bangladesh. For studying LULC change and cropping systems, images from Landsat (TM) of 1989, Landsat (ETM+) of 2000 and 2010, and Landsat (Oli) of 2019 were used. A focus group discussion (FGD) was conducted to gather information on actors driving LULC changes. In the study area, five LULC categories—cropland, accreted land, settlements, mangrove forests, and water bodies were found. It reveals that cropland increased by 0.20% annually, while water bodies, accreted land, and mangrove forest decreased by 0.29, 0.17, and 0.23%, respectively. Settlements grew relatively at a faster rate (0.49%). The major land conversions between 1989 and 2019 were cropland to settlement (10.2%), mangrove forest to settlement area (3.2%), and mangrove forest to cropland area (4.0%). Other transformations included the shifting of accreted land to cropland and water bodies to settlements. From 1989 to 2019, double cropland increased by 0.71% annually due to the conversion of single to double cropland. Increased population pressure, especially for those displaced by the threat of river erosion, was a major factor in the conversion of cropland and mangroves into settlements. Due to the high demand for food in the study area, mangrove forests were converted to cropland and single cropland to double cropland more rapidly. These findings will assist farmers, stakeholders, and planners in developing and implementing optimal land use planning and sustainable agricultural production strategies in the region.

Ann. Bangladesh Agric. (2023) 27 (1) : 1-15

Antifungal potential of commercial silver nanoparticles against rice blast pathogen Magnaporthe oryzae

2024-01-09T17:14:31+00:00

The rice blast caused by Magnaporthe oryzae is one of the major and recurrent threats to sustainable rice production in Bangladesh. To mitigate this problem, the present study was undertaken with the aim to investigate the inhibitory effects of commercially available silver nanoparticles (Ag-NPs) on the growth and development of Magnaporthe oryzae, and control of rice blast disease. In vitro experiments demonstrated that Ag-NPs significantly suppressed the radial growth of fungal mycelium, with the highest inhibition (83.54%) at a concentration of 250 ppm, while Trooper 75 WP at 400 ppm completely inhibited the fungal mycelial growth. The production of conidia and colony formation were also reduced significantly by Ag-NPs treatment. Furthermore, Ag-NPs exhibited a substantial inhibitory effect on the germination of M. oryzae conidia, with complete inhibition observed at concentrations between 200 and 250 ppm. Comparative analyses revealed that the fungicidal effect of Ag-NPs was superior to silver nitrate (AgNO₃), suggesting the augmented activity of the nano properties. The sensitivity of M. oryzae to Ag-NPs was determined by calculating EC₅₀ and EC₉₅ values, which indicated a mean EC₅₀ value of 131.5 ppm and a mean EC₉₅ value of 276 ppm. Additionally, in vivo experiments showed that preventive and curative treatments with Ag-NPs significantly reduced disease incidence and severity in rice plants infected with M. oryzae, with efficacy comparable to that of the fungicide Trooper 75 WP. At higher concentrations of Ag-NPs, preventive treatment was found to be more effective than curative treatment in disease control. These findings highlighted the potential of Ag-NPs as an effective alternative for the management of rice blast.

Ann. Bangladesh Agric. (2023) 27 (1): 17-30

Patterns of insecticide uses and its impact on the health of the farmers in Tangail district of Bangladesh

2024-01-09T18:30:16+00:00

Appropriate and judicious application of insecticide is the most effective measure of crop protection against the injury and damage of insect pests. However, the tendency of the farmers is to apply insecticide without maintaining proper dose, time and precautionary measures. This study was conducted in Dhanbari and Madhupur upazilas of the Tangail district during July to October 2020 to find out the patterns of insecticide use on summer vegetables and the potential risks of insecticides on the health of farmers. Data were collected from randomly selected 120 farmers through a pre-tested questionnaire. The majority of farmers within the study area obtained information regarding specific insect pests and the recommended insecticide from local retailer shops 81.7%), whereas information on insecticide dosage was primarily gathered from experts (91.7%). In the study area, farmers applied insecticides once/twice a season (66.7%). The survey report showed that 60.0% of the farmers applied insecticides without reading the label information, while all the farmers applied insecticides using hand driven sprayer machine between the hours of 10 am to 3 pm. Results revealed that 63.3% of the farmers took a moderate protective measures, but 93.3% did not consider pre-harvest Interval (PHI). A considerable portion of farmers (48.3%) kept pesticide bottles and packaging alongside other inputs, while most respondents (96.6%) disposed of these items in the fields. It was found that 70.0% of the farmers were acquainted with health hazards, 56.6% knew about water pollution, 54.1% knew about reduction of pollinators due to insecticide application. Based on the perspectives of the participants, it was also found that, 60.0% farmers suffered from physical weakness, 55.0% suffered in loss of appetite, 38.3% suffered in eye irritation, 28.3% experienced in body itching, and 12.7% suffered urinary and sexual disorder.

Ann. Bangladesh Agric. (2023) 27 (1): 31-39

Reduction of arsenic uptake in lentil through arbuscular mycorrhizal fungi

2024-01-10T01:35:48+00:00

Arsenic (As) is a carcinogenic and hazardous substance that poses a serious risk to human health. The present research focused on the transport of As in seven lentil varieties developed by the Bangladesh Agricultural Research Institute (BARI) viz., BARI Mashur1, BARI Mashur 2, BARI Mashur 3, BARI Mashur 4, BARI Mashur 5, BARI Mashur 6 and BARI Mashur 7 and the role of arbuscular mycorrhizal fungi (AMFs) in mitigating As phyto-toxicity in them. The transportation of As from soil to root, shoot, and grain was lower after week 13 than in weeks 6 or 10 after lentil seedling emergence. The As accumulation in grains was higher in BARI Mashur 1 than in other test genotypes. Treatment with AMF significantly increased growth and biomass accumulation in lentil genotypes compared to non-AMF plants. Furthermore, AMF effectively reduced As concentrations in roots and shoots of lentil plants grown in 8 and 45 mg kg-1 As-contaminated soils. This study revealed a remarkable variation among the BARI-developed lentil genotypes in terms of As accumulation in plant parts. Treatment with AMF could effectively reduce plant uptake of As and mitigate As-induced phytotoxicity in lentils. The results reveal a great potential of AMF to mitigate As toxicity in lentils caused by the transport of As from soil to the shoot mass and reallocation to grains. This may enable farmers to expand lentil cultivation in As- affected areas throughout the world.

Ann. Bangladesh Agric. (2023) 27 (1): 41-56

Assessment of spawning and nursery habitats of hilsa in the Tetulia and Meghna river estuaries

2024-01-11T10:44:28+00:00

The Meghna River estuary (MRE) and Tetulia River estuary (TRE) are tropical estuaries on the middle coast of Bangladesh. Hilsa shad (Tenualosa ilisha), is one of the most important anadromous fish (ascending rivers from the sea for breeding), migrates into the Meghna and Tetulia River estuarine systems from the Bay of Bengal. This study assessed the spawning and nursery habitats of hilsa in the Tetulia and Meghna River estuaries by examining the environmental parameters of both estuarine ecosystems. Water samples were collected from nineteen selected sampling sites along and across the estuaries from January to December 2021 covering both the dry and wet seasons. Salinity, dissolved inorganic nitrogen (DIN), and dissolved inorganic phosphorus (DIP) concentration varied significantly (p < 0.05) between the MRE and TRE during the dry season. In contrast, no significant variation (p > 0.05) was observed in the salinity, DIN and DIP between the MRE and TRE during the wet season. In addition, no significant variation (p > 0.05) was observed in chlorophyll-a concentration between the MRE and TRE during the dry and wet seasons. The salinity tolerance range is an important driver for the spawning (salinity <0.1 psu) and nursery (salinity <0~2 psu) habitat of hilsa. This study explored that the TRE is suitable for spawning and nursery habitat (salinity <0.09 psu) for hilsa all year round because the TRE acts as a freshwater ecosystem (salinity <0.1 psu) annually. Therefore, the government should focus on protecting and conserving juvenile hilsa (jatka) and brood hilsa in the TRE year round.

Ann. Bangladesh Agric. (2023) 27 (1): 57-69

Efficacy of bio-rational insecticide for eco-friendly management of pod borer of mung bean

2024-01-10T01:47:27+00:00

Pod borer species Maruca vitrata (Geyer) and Euchrysops cnejus (Fab.) are the major limiting constraints in mung bean. The present experiment was conducted in the experimental field of the Department of Entomology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh during March to June 2021 to develop an ecofriendly management approach against pod borer attacking mung bean. Four eco-friendly biopesticides (Biomax 1.8 EC (Abamectin) @ 1.2 ml/L, Tracer 45 SC (Spinosad) @ 0.4 g/, Fytomax PM (0.1% Azadirachtin) @ 5.0 ml/L, Neem Seed kernel Extract (NSKE) @ 50.0 g/L) and clean cultivation were tested against pod borers of mung bean variety BU mug 4. An untreated control treatment was maintained for comparison. The marginal benefit-cost ratio of the treatments and the impact of the treatments on the abundance of beneficial arthropods in the experimental plots were recorded. The management approaches did not affect the abundance of beneficial arthropods in the bean field. The findings revealed that the lowest rate of pod infestation (1.9% by n/n and w/w) as well as the highest marketable yield (1.55 MT/ha) and marginal benefit- cost ratio (3.02) were obtained with the foliar spray with Tracer 45 SC (Spinosad) @0.4 g/L of water at 15 days interval. Tracer 45 SC (Spinosad) @ 0.4 g/L of water at 15 day intervals is an effective, suitable, and viable approach for suppressing pod borer complex without harm to beneficial arthropods in the mung bean field.

Ann. Bangladesh Agric. (2023) 27 (1): 71-79

Population dynamics of Trichoderma harzianum in bio- fortified compost against soil-borne potato diseases

2024-01-10T01:59:39+00:00

Soil-borne diseases pose significant challenges to global potato cultivation, resulting in yield losses and economic implications. Utilizing biological control agents offers a sustainable and environmentally and friendly approach to manage these diseases. Before implementing the experiment in the field, a series of in-vitro tests were conducted to select a virulent isolate of the tested pathogens and an effective antagonistic isolate of Trichoderma harzianum. In the pathogenicity test, isolate RS-1 of Rhizoctonia solani and isolate SR-8 of Sclerotium rolfsii exhibited the highest virulence against two pathogens in potato variety ‘Cardinal’ in regard to seedling mortality (44.44-88.88%). During in vitro screening, T. harzianum isolate Tri 7 displayed the greatest ability to inhibit the mycelium growth of all tested pathogens. In the field trial, the highest seedling mortality (69.06%) was observed in T₂ (Fresh seeds+ Soil inoculated with R. solani and S. rolfsii). However, the highest seedling mortality (86.94%) was reduced by treatment T₇ (Fresh seeds+ Soil inoculated with R. solani and S. rolfsii +500g wheat grain colonized with Trichoderma fortified poultry compost). Treatment T₇ also recorded the lowest incidences of stem canker (7.83%) and stem rot (8.64%), whereas the highest disease incidences occurred in the T₂ treatment plot. Notably, treatment T₇ gave the highest yield of 30.94 tons/ha, while the control plot T₂ yielded the lowest at 12.17 tons/ha. Initially, Trichoderma population was minimal prior to the application of Trichoderma- fortified compost. However, populations gradually increased over time, peaking at 3 months across all treatments except the control, where no Trichoderma was applied. However, a decline in T. harzianum population was noted one month after potato harvesting. This approach offers a potential solution for managing potato soil-borne diseases in a sustainable and environmentally friendly manner.

Ann. Bangladesh Agric. (2023) 27 (1): 81-92

Growth inhibition of Salmonella by Leuconostoc species isolated from buffalo milk curd

2024-01-10T02:09:57+00:00

Traditional fermented products are considered to be a niche for microbial diversity. Probiotics offer a unique approach for addressing the threat of antibiotic resistance. Therefore, the aim of the present study was to isolate Leuconostoc spp. from Buffalo milk curd, an artisanal fermented dairy product in Bangladesh and assess their growth inhibition competence against Salmonella sp. A total of 50 isolates were isolated and purified from five freshly prepared buffalo milk curd samples using two different media, with glucose or sucrose as the carbon source. Among these pure isolates, 37 were identified as presumptive Leuconostoc spp. The biochemical identification using the VITEK 2 system confirmed that 59.5% of the isolates were Leuconostoc mesenteroides ssp. cremoris, while 40.5% were Leuconostoc pseudomesenteroides. Out of the identified isolates, twelve had a similarity of over 97%, and twenty-five had a similarity of less than 96%. Consequently, these twelve isolates were tested for their antimicrobial activity against Salmonella sp. using two in vitro methods, agar well diffusion and microbroth. The isolate M1L1 exhibited the highest inhibitory zone (15 mm) and showed 55.6% growth inhibition by the agar well diffusion and microbroth assay, respectively, suggesting a similar efficacy between the two methods. Notably, five other isolates also displayed inhibitory zones ranging from 13 to 15 mm and growth inhibition percentages of 37 to 52%. Overall, the isolated Leuconostoc spp. could be utilized as probiotics to combat pathogenic microorganisms.

Ann. Bangladesh Agric. (2023) 27 (1): 93-104

Use of social media by the farmers in Gazipur district of Bangladesh

2024-01-11T08:21:17+00:00

Bangladesh has embraced digitalization to the point where social media has become an essential tool for communication among all sectors of people, including agriculture. The current study was, therefore, attempted to ascertain the extent of use of various social media platforms by the farmers. The study was conducted in two Upazilas viz. Sreepur and Gazipur Sadar Upazila of Gazipur district. A total of 100 farmers were selected as a sample of the study following a proportionate random sampling technique. Four-fifths (80.0%) of them had poor to moderate knowledge of social media use. Among the digital social media, Knowledge on smartphones ranked first. The use of different social media by the majority (84.0%) of respondents was impressive, where 33.0 percent had low use and 51.0 percent moderate. Watching the Hridoye Mati O Manshu program on Facebook / YouTube ranked 1st position for using agricultural purposes. In the case of non-agricultural purposes, the use of Messenger / Imo / WhatsApp to communicate with relatives/friends ranked in 1st position. Moreover, around half of the respondents (51.0%) preferred Facebook among other social media due to its multidimensional usage. The majority of the respondents showed as moderate users (4-9 years) of different social media using experiences. The vital preference of using social media is to communicate with others, followed by 'entertainment' and 'ease of handling'. Level of education, farm size, and annual income showed a positive significant relationship with the extent of use of different social media by the farmers, while age and farming experience indicated a negative significant relationship. 'Network problems', 'load shedding', 'high cost', 'poor Wi- Fi' service, and 'addiction to overuse of social media' were some of the major problems identified by the respondents in using social media.

Ann. Bangladesh Agric. (2023) 27 (1): 105-120

Seroprevalence and molecular detection of infectious laryngotracheitis virus (ILTV) in commercial chicken in Gazipur district of Bangladesh

2024-01-11T11:01:30+00:00

Infectious laryngotracheitis (ILT) is one of the major diseases of chickens that cause great economic losses in commercial chicken farms. It is caused by the infectious laryngotracheitis virus (ILTV). This research work was designed to investigate the seroprevalence of ILTV in commercial chicken farms in Gazipur district. A total of 590 blood sera were collected randomly from commercial chicken farms from different locations in Gazipur district. An antigen-coated indirect ELISA was performed to determine the antibody titer against ILTV in these sera. Moreover, gross and histopathological changes in different organs were investigated. Polymerase chain reaction (PCR), a molecular detection method, was performed to detect the fragment of the glycoprotein ‘C’ (gC) gene of ILTV in the infected chicken. Overall, 195 out of 590 serum samples were positive for anti-ILTV IgG, representing 33.05% of positive cases. The highest mean titer of ILTV antibody was found in anti-ILTV-vaccinated layer chickens with a mean titer of 3554. In seasonal variation, the highest prevalence of ILTV was recorded during the winter, followed by the rainy and summer seasons. The prevalence of ILTV was the highest at the age of 10-30 weeks in layer chickens. Necropsy findings of dead chickens showed severe congestion and fibrosis in the lungs and trachea, with occlusion of the tracheal lumen by mucus, caseous exudates and blood. Microscopically, hemorrhage and huge infiltrations of inflammatory cells were found in trachea and lungs. Moreover, the nucleotide sequence of ‘gC’ gene of ILTV was amplified successfully and yielded 1.26 kbp amplicons. This study suggested that ILTV was endemic in Gazipur district and the PCR technique is a useful molecular tool for diagnosis of ILTV in the commercial chicken industry.

Ann. Bangladesh Agric. (2023) 27 (1): 121-135