Bio vs. Conventional: The decisive match in Slovenian vineyards
Climate challenges in modern vineyards
The Goriška Brda region in Slovenia is increasingly affected by climatic variability. Summers are hotter, rainfall patterns irregular, and humidity levels remain high during sensitive phases of grapevine development. These factors create favorable conditions for fungal pathogens such as downy mildew and powdery mildew. While conventional treatments offer protection, their environmental impact and incompatibility with organic certification push growers toward eco-friendly alternatives.
Research and field testing
Metrob, in collaboration with viticulturist Damijan Koncut, conducted vineyard trials comparing three scenarios:
- Untreated control plot, to assess natural disease pressure.
- 100% ecological program: Fytosave® + Copfort + seaweed extracts + microbiological products.
- Conventional program, using standard synthetic fungicide treatments..
This setup allowed both narrative observation and structured comparison of approaches.
Products in the ecological program
- Fytosave® (Metrob): a plant elicitor (oligosaccharides) that stimulates the vine’s immune system, protecting against downy and powdery mildew. Applied preventively (300–400 mL/100 L in hobby vineyards).
- Copfort (Metrob): systemic copper solution, effective in organic programs, ensuring robustness under high disease pressure.
- Seaweed extracts & microbiological products: to reduce abiotic stress, support physiology, and prolong leaf functionality.
Results
Untreated control
As soon as rains began, downy mildew developed rapidly on leaves, then spread to grape clusters. Later in the season, powdery mildew established itself during hot and dry periods. The vineyard’s sanitary state deteriorated, leading to heavy qualitative and quantitative losses.
100% Ecological program (Metrob)
With Fytosave® applied preventively, downy mildew pressure remained low. Infections were delayed, and outbreaks limited. Powdery mildew symptoms were also visibly reduced compared to both control and mixed programs. Copfort ensured stable protection during consecutive rain events, while seaweed and microbiological products improved leaf turgor, recovery after stress, and canopy longevity. Grapes were uniform, healthy, and visually superior.
Applications: The ecological program required 11 sprayings throughout the season, while the conventional program required 10. Despite this slight difference, the overall cost was similar. The key to success was not the number of applications, but their timing in relation to weather conditions, ensuring maximum preventive protection.
Conventional program
The conventional program provided protection against both downy and powdery mildew, but results varied depending on weather conditions and timing. While it reduced disease incidence, it also left chemical residues and was less aligned with sustainability and organic standards.
| Approach | Downy Mildew | Powdery Mildew | Foliage / Physiology | Residues | Applications |
| Untreated control | Severe, rapid development | Established after heat waves | Degraded, heavy losses | None | 0 |
| Ecological program | Contained pressure, delayed infection | Significantly reduced symptoms | Durable foliage, fast recovery | None | 11 |
| Conventional program | Variable, depending on timing | Reduced but residues remained | Functional but less resilient | Present | 10 |
Integrated observations
During critical periods (flowering to veraison), clear differences were visible:
- In the control, disease symptoms expanded unchecked, compromising yield.
- In the ecological program, vines remained vigorous, with healthy leaves and grape clusters, providing evidence of systemic resistance induced by Fytosave®.
- The conventional program controlled disease but lacked the ecological consistency and left residues.
Conclusion
The trials demonstrate that only the 100% ecological program provided coherent, residue-free protection against both downy and powdery mildew, while supporting vine resilience and grape quality. Importantly, the trials showed that the overall costs of protection were similar between the ecological and the conventional programs. The difference was not in expenses, but in outcomes: the ecological approach delivered consistent, residue-free protection, while the conventional left chemical residues.
With comparable application costs and frequency, Metrob’s ecological approach proved that sustainability and performance can go hand in hand.
