Rhizoctonia crown rot and canker caused by Rhizoctonia solani and southern blight caused by Sclerotium rolfsii are the two main devastating diseases that hamper carrot production greatly in Bangladesh. Indiscriminate use of chemical fungicides in controlling the pathogens also pollutes the environment, so an alternative bio-control agent was used to control the diseases. In the pathogenicity test, R-1 isolate of R. solani and S-1 isolate of S. rolfsii were found to be the most virulent against carrot seedlings and harvested carrots. T. harzianum isolate Pb-7 was appeared to be the most effective antagonist in the preliminary screening against both the selected pathogens. The field experiment was laid out following randomized complete block design with five treatments and three replications. In pathogen inoculated fields, 200g and 400g wheat grain colonized Trichoderma fortified compost, composted poultry refuges were mixed in the soil as per treatment before sowing carrot seeds. Pre- and post-emergence seedling mortality, incidence of Rhizoctonia crown rot and canker, and southern blight of carrot reduced significantly in treatments where soil was amended by wheat grain colonized Trichoderma fortified compost. On the contrary, pre- and post-emergence seedling mortality, incidence of Rhizoctonia crown rot and canker and southern blight of carrot was highest in pathogen inoculated fields. Trichoderma fortified compost enhanced germination percentage, growth promoting factors, yield and yield contributing components. The concentration of 400g wheat grain colonized Trichoderma fortified compost can be a suitable alternative to chemical fungicides used against these two devastating diseases of carrot.

Salinity is a severe environmental threat causing low productivity in field crops. Rice is a staple crop of the world whose yield and quality is highly affected by the salt content in the root zone. Nutrient management, however, is a key factor that can be used to boost rice production in saline soils. Boron (B), a micronutrient with diverse functions, plays a significant role in rice yield. However, little is known about the effects of B under saline conditions on the yield of rice components. ‘Swarna,’ is a local and salt-sensitive rice variety from Bangladesh. A field experiment was conducted in salt-treated soils to assess the possible functions of B for the improvement of ‘Swarna’ yield. The current study showed that B applications substantially improved the length and weight of panicles, number of tillers and grains, seed weight as well as the yield of grain and straw, indicating its role in rice production in saline environments.

The phyllosphere, the aerial part of plants, serves as a crucial habitat for diverse microorganisms. Phyllosphere bacteria can activate protective mechanisms that help plants resist disease. This study focuses on isolating and characterizing phyllosphere bacteria from cucurbits to evaluate their potential in controlling Colletotrichum orbiculare, a pathogen causing anthracnose in cucumbers. Among the 76 bacterial isolates collected, 11 exhibited strong antagonistic effects against C. orbiculare in vitro. Morphological and 16S rRNA analyses identified these isolates as different Bacillus species, including B. vallismortis, B. velezensis, B. amyloliquefaciens, and B. subtilis. These bacteria demonstrated essential plant-growth-promoting and biocontrol traits, such as motility, biofilm formation, phosphate solubilization, nitrogen fixation, and the production of indole acetic acid. Most of the bacterial strains also produced biocontrol compounds such as ammonia, acetoin, siderophores, hydrogen cyanide, chitinase, protease, lipase, and cellulase. The application of these bacteria significantly enhanced cucumber growth in both non-manured and organically manured soils, showing improvements in root and shoot length, chlorophyll content, and biomass accumulation. Additionally, bacterial treatments effectively reduced anthracnose severity, with isolates GL-10 and L-1 showing the highest disease suppression in both soil types. Colonization studies showed that phyllobacteria preferentially colonized healthy leaves over roots and diseased tissues, and they were more effective in manure-amended soils. These results suggest that Bacillus phyllobacteria have strong potential as sustainable bio-stimulants and biocontrol agents, offering an effective approach for enhancing cucumber growth and disease control under both fertilized and unfertilized soil conditions.

The present study investigated the phosphate solubilizing potential and in vitro plant growth enhancing capability of five bacterial isolates of Pseudomonas sp. isolated from the endophytic region of three different weeds namely Cyperus rotundus, Amaranthus spinosus, Scirpus mucronatus which were collected from the coastal region of Bangladesh. The bacterial species were identified as Pseudomonas sp. based on their morphological characteristics. For further confirmation molecular characterization will be done. The isolates of Pseudomonas sp. showed varying degree of phosphate solubilizing potential on pikovskaya's media. The results showed that isolate EnAgM3 had the utmost capability of phosphate solubilization with the competency of (77.43±0.65 %) and the second place was occupied by the isolate EnAgM2 with their competency of (74.92±0.95%). Then the isolates were used for the assessment of their in vitro growth promoting capability of wheat (Triticum aestivum). Isolate EnAgM3 showed the best growth promotion in respect of all the parameters studied except root fresh ounce whereas EnAgM2 also significantly enhanced all the parameters except germination percentage in comparison to control. Conclusively, this study revealed that the unexplored coastal region of Bangladesh hold potential microorganisms having phosphate solubilizing and potential of plant growth enhancement. As far as we know, it is the first comprehensive study conducted for isolating Pseudomonas sp. as the endophytic bacteria from the coastal weeds of Bangladesh and to identify their in vitro potential of phosphate solubilization as well as plant growth enhancement of wheat.