Some people believe that talking to your plants makes them thrive. While there’s limited scientific support for sound improving plant health, there’s a growing amount of evidence about the benefits of mechanical stimulation, like touch, wind or rain. Researchers reporting in ACS’ Journal of Agricultural and Food Chemistry examined the impact of watering practices on tomato plants. They found that the size of the water droplets affected plant growth and resistance to pests and pathogens.
Climate change threatens crop production as rising temperatures, unstable rainfall patterns, and more insects and diseases endanger plant health and yields. Thus, there is growing pressure to identify ways to moderate these environmental effects, ideally without increasing the use of chemical pesticides. To address this challenge, Man-Qun Wang and colleagues examined how mechanically stimulating tomato plants with water droplets impacts their growth and might protect them from insect predation and fungal infection.
The researchers sprayed tomato plants with water twice daily and compared the effects of small droplets (200 micrometers, about the size of a computer monitor pixel) and large droplets (1,000 micrometers, about the diameter of a pinhead) versus no spray. They also covered the soil with a barrier to ensure the spray didn’t influence how much water the roots received.
Structural observations revealed:
- Tomato plants sprayed with large water droplets were shorter and more compact than other groups.
- There were minimal visible differences between plants receiving small droplets or no spray.
- Fruit yield and quality were similar among the three groups.
Metabolic analysis revealed that tomato plants sprayed with large water droplets had:
- Significant changes in hormones involved in plant defenses, resulting in increased resistance to destruction by moth larvae or gray mold compared to plants that weren’t sprayed.
- Higher levels of defense-mediating chlorogenic acid in their leaves compared to the other plant groups.
- Reduced emissions of volatile organic compounds compared with plants receiving no spray, which made them less attractive to egg-laying moths and resulted in 74% fewer eggs on the leaves.
Given these results, the researchers suggested that continued developments in water spray technologies and droplet atomization could improve agricultural practices, making farming greener and more efficient.
The authors do not acknowledge a funding source for this study.
###
The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.
Registered journalists can subscribe to the ACS journalist news portal on EurekAlert! to access embargoed and public science press releases. For media inquiries, contact newsroom@acs.org.
Note: ACS does not conduct research but publishes and publicizes peer-reviewed scientific studies.
Follow us: X, formerly Twitter | Facebook | LinkedIn | Instagram
Journal
Journal of Agricultural and Food Chemistry
Article Title
“Suprathreshold Water Spray Stimulus Enhances Plant Defences against Biotic Stresses in Tomato”
Article Publication Date
9-Sep-2024