Ophiopogon japonicus (Mai Dong), a valued medicinal herb in Traditional Chinese Medicine (TCM), requires specialized cultivation techniques to maintain product quality. Among these, manual weed control remains a critical practice, particularly for addressing Cyperus rotundus (nutgrass) infestations while preserving medicinal purity.
The Challenge of Nutgrass in Ophiopogon Cultivation
1. Biological Characteristics of Cyperus rotundus
- Rapid vegetative propagation through rhizomes and tubers
- High competitive capacity for nutrients, water, and sunlight
- Persistent soil seed bank with extended dormancy periods
2. Herbicide Incompatibility with Medicinal Cultivation
- Ophiopogon’s shallow root system (5-10cm depth) shows high sensitivity to chemical residues
- Risk of bioactive compound contamination in harvested rhizomes
- Potential soil microbiome disruption affecting long-term field productivity
Manual Weed Management Protocol
1. Operational Methodology
- Tools: Short-handled hoe (15-20cm blade), hand trowel, collection baskets
- Technique:
- Soil loosening around weed base (2-3cm depth)
- Complete rhizome extraction using pincer grip technique
- Minimal soil disturbance within 5cm radius of Ophiopogon plants
2. Optimal Timing and Frequency
- Early morning operations (0600-0900) during dew period for easier extraction
- 7-10 day intervals during peak growing season (May-September)
- Pre-flowering removal to prevent seed set
Technical Advantages of Manual Control
- Quality Assurance
- Zero chemical residues in final product
- Preservation of bioactive compounds (ophiopogonin D, ruscoside)
- Agroecological Benefits
- Maintenance of beneficial arthropod populations
- Prevention of herbicide resistance development
- Soil structure preservation
Manual weed management in Ophiopogon cultivation represents an essential practice combining traditional knowledge with modern quality standards. This labor-intensive approach ensures:
- Pharmaceutical-grade raw material production
- Sustainable field ecosystem maintenance
- Compliance with international organic certification requirements
