Pyroligneous Acid Increases Cucumber Yield By 48% in Organoponic Systems
Introduction
Cucumber (*Cucumis sativus L.*) is a widely cultivated vegetable with high economic and nutritional value. However, in Cuba, cucumber yields are often lower than in other regions, averaging around 12.76 t/ha. Organoponic systems, a form of urban agriculture integrating organic amendments and biostimulants, have been introduced to improve production efficiency. Pyroligneous acid (PA), a byproduct of wood pyrolysis, has shown promise as a natural biostimulant, enhancing plant growth and yield.
Experimental Design and Application
A completely randomized design was used to assess PA application through foliar spraying and substrate incorporation, which involved applying PA directly to the soil around plant roots to assess its impact on root absorption and soil conditioning. The study included seven treatments:
- Foliar application: 5 mL/L (FD1), 10 mL/L (FD2), 15 mL/L (FD3)
- Substrate application: 5 mL/L (SD1), 10 mL/L (SD2), 15 mL/L (SD3)
- Control (C): No PA application
PA was applied at 7, 14, and 21 days after germination. Each treatment had three replicates with 15 plants per replicate. At 21 days, growth parameters such as stem length, base diameter, number of leaves, and leaf area were measured. Yield-related variables, including fruit number and size, were recorded at harvest.
Key Findings
The application of PA had significant effects on cucumber growth and yield, with the most notable results at lower concentrations.
| Treatment | Stem Length (cm) | Leaf Area (cm²) | No. of Branches | Yield (t/ha) |
|---|---|---|---|---|
| FD1 (5 mL/L Foliar) | 38.5 | 220.4 | 6.2 | 50.2 |
| FD2 (10 mL/L Foliar) | 36.1 | 210.2 | 5.8 | 47.5 |
| FD3 (15 mL/L Foliar) | 33.4 | 195.1 | 5.1 | 40.6 |
| SD1 (5 mL/L Substrate) | 34.8 | 200.3 | 5.4 | 42.3 |
| SD2 (10 mL/L Substrate) | 35.2 | 205.7 | 5.9 | 45.6 |
| SD3 (15 mL/L Substrate) | 31.9 | 185.4 | 4.9 | 38.2 |
| C (Control) | 29.3 | 170.2 | 4.5 | 33.8 |
Implications
- The most effective treatment was 5 mL/L foliar application, which enhanced growth and yield significantly compared to higher doses and control treatments.
- PA application increased cucumber yield by up to 48.6% over the control, highlighting its potential as a biostimulant.
- Foliar PA at 5 mL/L stimulated branch formation and expanded leaf area, supporting better photosynthetic efficiency.
- Higher doses (15 mL/L) showed diminishing returns, possibly due to phytotoxic effects, indicating an optimal PA threshold.
Conclusion
Pyroligneous acid demonstrates strong potential as a biostimulant for cucumber cultivation in organoponic systems. The best results were observed at a 5 mL/L foliar application, which maximized plant growth and yield. Future research should explore PA’s long-term effects, its interactions with other biostimulants, and its biochemical impact on cucumber metabolism.
Article based on: Rondón-Estrada et al. (2024) Influence of pyroligneous acid on cucumber cultivation under organoponic conditions.