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The aim of this review paper is to identify the production trends of shrimp and rice farming systems and associated hydrobiological parameters such as salinity in the coastal districts of Bangladesh. An intensive literature review has been conducted to explore salt stress-driven land use change, crop production, and changing ecosystem hydrobiology to adapt climate change impact from 2012–2022. The results indicate that a gradual extension of salt-driven land use and land cover (LULC) change has stressed agricultural production to a greater extent from 1973 to 2022 due to the high level of salinity. The unplanned expansion of shrimp culture is creating adverse consequences for the coastal ecosystem. Some suggestions have been proposed by analysing the mechanisms of crops' response to salt stress, including several physiological, biochemical, and molecular bases to mitigate the adverse effects of salinity on agricultural production. Alternatively, prawn, shrimp, and crab have similar or slightly higher economic outputs, except for the crop-based agricultural system, which is highly affected by salinity rise. However, due to low input costs, low maintenance, and less environmental impact, farmers are shifting towards crab fattening and thus changing the hydrobiology of coastal land use and land cover. [ABSTRACT FROM AUTHOR]

Gordon Conway postulated that in comparison to traditional agroecosystems, crop yields from modern agroecosystems are: (1) higher; (2) less sustainable; and (3) more variable, particularly in the early adoption stages. The existing literature predates more recent developments and does not employ long-term time series data to identify time phases using any econometric tests for structural breaks. This paper fills this gap by investigating the applicability of Conway's hypotheses to Bangladeshi rice yields over sixty years examining trends, their sustainability, and their variability. We find mixed support for Conway's hypotheses. Rice yields rose substantially following the Green Revolution. Overall, higher yields have been sustained. However, they have now virtually plateaued, and various factors (including environmental and ecological) have increased the risk of these yields becoming unsustainable. Until recently, absolute variations in Bangladesh's rice yields were found to be higher than before the Green Revolution. This supports Conway's third hypothesis. However, the relative variability of Bangladesh's rice yields has consistently fallen since the Green Revolution. We highlight the trio of general factors determining rice yields and underscored the need for holistic analysis. Non-economists often overlook economic factors while economists often do not pay adequate attention to eco-environmental factors. [ABSTRACT FROM AUTHOR]

Bakanae is one of the important diseases of rice in Bangladesh that causes substantial yield loss every year. We collected thirty isolates of Fusarium spp. from bakanae-infected rice plants from different agroecological zones of Bangladesh and investigated the variations in cultural and morphological characteristics and pathogenicity. Diversity was found in cultural characteristics, viz., colony features, phialide, chlamydospore formation, shape, and size of macro- and microconidia. Three variants of Fusarium species such as F. moniliforme, F. fujikuroi, and F. proliferatum were identified on PDA media based on their cultural and morphological characteristics. Isolate FM10 (F. moniliforme) exhibited the highest disease aggressiveness in developing elongated plants (26.50 cm), the highest number of chlorotic leaves (5.75), and a lower germination percentage. We evaluated different bioagents against the virulent isolate of F. moniliforme to develop a rice bakanae disease management approach. Four bioagents, viz., Trichoderma spp., Bacillus subtilis, Pseudomonas fluorescens, and Achromobacter spp., were evaluated for growth suppression of F. moniliforme. Among the bioagents, Achromobacter spp. and B. subtilis (BS21) showed 73.54% and 71.61% growth suppression, respectively. The investigation revealed that the application of Achromobacter spp. and B. subtilis (BS21) would be a potential candidate for effective and eco-friendly management of the bakanae disease of rice. [ABSTRACT FROM AUTHOR]