Plant extract bioassay using soil seed bank for herbicidal and fungicidal testing

Overview

This research proposes using the natural richness of soil seed banks containing weeds and pathogenic fungi as a reliable biological testing material. Soil samples collected from maize, rice, and cassava fields reveal high infestation potential, with over 40 million weed seeds per hectare identified. By germinating these weeds under controlled conditions, researchers can systematically evaluate the biological efficacy of plant extracts as natural herbicidal and fungicidal agents. This approach supports the development of bio-based crop protection solutions relevant to agricultural systems in regions producing staple crops.

Technical specifications

• Soil sampling uses a 5 cm diameter auger at 20 cm depth, the layer where maximum weed seed concentration occurs
• Field evaluations have been conducted in maize, rice, and cassava cropping systems
• Plant extracts are prepared by suspending increasing amounts of plant powder in 100 ml of distilled water based on dosage
• Aqueous extracts undergo maceration for at least 20 hours under laboratory conditions at 25 to 30°C
• The methodology enables dose-response testing of three plant extracts against germinating weed species and pathogenic fungi
• Requires greenhouse infrastructure for weed germination and laboratory equipment for extract preparation and purification

Technology readiness level

The project is at an early-to-intermediate research stage. Initial soil seed bank evaluations have been completed in maize, rice, and cassava fields, confirming the abundance of weed seeds suitable for bioassay work. Future validation requires a two-year study period focused on greenhouse-based weed germination trials and laboratory preparation of plant extracts. The research team is seeking partnership support to finalize greenhouse construction, equip the laboratory, and purify the most promising plant extracts for further development toward practical bio-based herbicide and fungicide applications.