Plant Extracts as Dual-Action Agents: Biostimulation and Biocontrol Strategies for Sustainable Crop Production

Plant extracts offer a promising, eco-friendly solution for sustainable agriculture, acting as both biostimulants and bioprotectants. Their rich array of bioactive compounds enhances crop growth, improves resilience to environmental stressors like drought and heat, and provides natural protection against pests and diseases.

Recent research highlights the dual functionality of these extracts. A study on rice (Oryza sativa) showed that aqueous extracts from guava, aloe vera, garlic, and alfalfa, applied through soil irrigation and transplanting, significantly promoted growth. Specifically, low concentrations (0.1% and 0.5%) boosted shoot and root growth by 40–70%. This benefit was linked to enhanced photosynthesis and antioxidant activity.

Another study investigated the antifungal properties of various aqueous plant extracts against soybean pathogens. Hot water extractions, such as infusions and decoctions from plants like flaxseed and marigold roots, demonstrated strong inhibitory effects on fungal growth in vitro. This suggests that these biodegradable extracts could serve as a viable alternative to synthetic fungicides.

The effectiveness of plant extracts lies in the synergistic interactions of their components, which makes it difficult for pests to develop resistance. These extracts represent a cost-effective and low-tech option for farmers. However, further research is necessary to standardize extraction methods, fully understand their molecular mechanisms, and validate their efficacy in real-world field conditions to facilitate their widespread adoption in sustainable farming practices.