Impact of Wood Biochar Doses on Vegetative Growth of Cauliflower (Brassica oleracea var. botrytis) in Coastal Saline Soils of Bangladesh

Jannatul Ferdous — 2026-03-23

Background: Continuous cropping and intensive agricultural practices have led to the degradation of many productive soils, resulting in problems such as loss of organic matter and nutrients, drought stress, erosion, waterlogging, salinity, and soil compaction. Biochar has been reported to stimulate plant growth by improving soil structure, enhancing nutrient availability, and increasing soil water-holding capacity. Furthermore, the porous structure of biochar provides a favorable habitat for microorganisms such as bacteria, actinomycetes, and arbuscular mycorrhizal fungi, thereby enhancing soil microbial activity

Aims: The present study evaluates the effects of varying wood biochar doses on growth parameters (plant height, leaf number, leaf breadth, and leaf length) of cauliflower in coastal Bangladesh, and assess its potential as a soil amendment for challenging environments.

Study Design: Randomized Complete Block Design with three replications.

Place and Duration of Study: Noakhali Science and Technology University Campus, Noakhali, Bangladesh, from January to March 2022.

Methodology: Five treatments were tested: T₀(0 ton/ha, control), T₁ (2 ton/ha), T₂(4 ton/ha), T₃ (6 ton/ha), and T₄(8 ton/ha) Meheguni wood biochar. Each plot contained 6 plants per plot. Growth parameters were measured at 20, 40, and 60 days after transplanting (DAT).

Results: Biochar significantly influenced all four growth parameters (p < 0.05). Plant height increased with higher doses; maximum values were 17.72 cm (T₄) at 20 DAT, 33.97 cm (T₄) at 40 DAT, and 38.75 cm (T₄) at 60 DAT. Leaf number peaked at 10.77 (T₃) at 20 DAT, 12.88 (T₃) at 40 DAT, and 15.56 (T₄) at 60 DAT. Leaf breadth was highest in T₃: 5.8 cm at 20 DAT, 12.53 cm at 40 DAT, and 15.45 cm at 60 DAT. Leaf length reached 14.68 cm (T₃) at 20 DAT and 31.11 cm (T₄) at 40 DAT. No significant effects on development or yield were observed.

Conclusion: Wood biochar at 6-8 ton/ha enhanced vegetative growth of cauliflower, but failed to improve development or yield amid coastal challenges like salinity, waterlogging, and temperature fluctuations. Further studies are needed to optimize biochar for such conditions. These findings demonstrate the potential of biochar to support growth under stress conditions but also indicate the need for optimized application strategies to improve yield.

Insecticidal Activities of Some Tropical Plants Extracts against Malaria Mosquito, Anopheles gambae Giles (Diptera: Culicidae)

Obembe Olusola Michael — 2026-03-28

Anopheles mosquitoes are the primary vectors responsible for transmitting malaria-causing protozoans that affect populations worldwide. The use of synthetic insecticides to control mosquito populations can result in environmental pollution, human health risks, and depletion of the ozone layer. Consequently, there is a growing interest in identifying alternatives to synthetic insecticides. Botanical insecticides, which are inexpensive, readily available, and environmentally friendly, have emerged as viable options. This study investigated the insecticidal effects of methanol, ethanol, n-hexane, and acetone crude leaf extracts from Moringa oleifera, Eucalyptus citriodora, Mentha piperita, Azadirachta indica, and Andrographis paniculata on both adult and larval stages of Anopheles gambiae. Fresh leaves of the selected plants were collected, air-dried, and ground into powders. These powdered leaves were then extracted using absolute ethanol, methanol, n-hexane, and acetone at 60 °C in a Soxhlet extractor. Extract concentrations of 100, 150, 200, 250, and 300 ppm were prepared and tested against An. gambiae larvae and adults, with mortality recorded after 24 hours of exposure. The results demonstrated that ethanol and methanol extracts exhibited strong insecticidal activity, achieving 100% larval mortality at concentrations of 200, 250, and 300 ppm, and 100% adult mortality at 300 ppm. In contrast, n-hexane and acetone extracts showed limited activity against adult An. gambiae. Among the extracts tested, A. indica ethanol extract was the most potent, inducing 100% adult mortality at 300 ppm and complete larval mortality at 200 ppm. These findings indicate that leaf extracts of the tested plants, particularly A. indica, have significant potential for controlling both larval and adult An. gambiae. They may therefore serve as effective, eco-friendly alternatives to synthetic insecticides.

Asian Plant Research Journal

Impact of Wood Biochar Doses on Vegetative Growth of Cauliflower (Brassica oleracea var. botrytis) in Coastal Saline Soils of Bangladesh

Insecticidal Activities of Some Tropical Plants Extracts against Malaria Mosquito, Anopheles gambae Giles (Diptera: Culicidae)