Many believe that speaking to plants helps them grow better. Although there isn’t much scientific evidence to support the idea that sound improves plant health, research is increasingly showing the benefits of mechanical stimulation, such as touch, wind, or rain. A study published in ACS’ Journal of Agricultural and Food Chemistry investigated how different watering methods impact tomato plant growth. The researchers discovered that the size of the water droplets influenced plant growth and their ability to fend off pests and diseases.
Climate change poses a significant threat to agricultural production due to rising temperatures, unpredictable rainfall, and an increase in pests and diseases that jeopardize plant health and productivity. Consequently, there is an urgent need to find solutions to mitigate these environmental challenges without relying heavily on chemical pesticides. To tackle this issue, Man-Qun Wang and his team explored how the mechanical stimulation of tomato plants using water droplets might affect their growth and provide protection against insect damage and fungal infections.
The researchers applied water to tomato plants twice daily and analyzed the impact of different droplet sizes: small droplets (200 micrometers, similar to a computer monitor pixel) and large droplets (1,000 micrometers, roughly the size of a pinhead), compared to a control group with no water spray. They also used a barrier to prevent the spray from affecting the amount of water absorbed by the roots.
Structural observations showed:
- Tomato plants treated with large droplets were shorter and more compact than the other groups.
- There were slight visible differences between the plants that received small droplets and those that did not receive any spray.
- The fruit yield and quality were comparable across all three groups.
The metabolic analysis indicated that the tomato plants exposed to large droplets had:
- Notable changes in hormone levels related to plant defense, leading to enhanced resistance against damage from moth larvae and gray mold, compared to the non-sprayed plants.
- Higher concentrations of chlorogenic acid, which plays a role in defense, within their leaves compared to the other groups.
- Decreased emissions of volatile organic compounds, making them less attractive to egg-laying moths, resulting in 74% fewer eggs on their leaves.
Based on these findings, the researchers proposed that advancements in water spraying technology and droplet atomization could enhance agricultural practices, promoting more sustainable and efficient farming methods.
