Emily Chan
The team observed a 40 to 50 percent reduction in spider mites on plants that were sprinkled regularly with small amounts of water compared to those that were not sprayed. Similar results were previously seen in strawberry plants.
“The effect was on par with spraying once with a miticide if we count the mites a couple of weeks after spraying. Spider mites simply don’t thrive in a moist environment,” Trandem said.
“Predatory mites, on the other hand, which are natural enemies of the spider mites, prefer a slightly humid environment. In other words, this treatment can also create favorable conditions for biological control.”
The treatment does not completely get rid of the mites—it just keeps their populations reduced enough to prevent major damage to the plants.
In addition, the spraying must be done during periods of warm weather. The water has to evaporate quickly to avoid the onset of fungal diseases like gray mold.
Other forms of water are being tested to eliminate plant pests. For one project, researchers looked into how steam can decrease fungal and pest infections using what’s called the Plant Sauna.
In the Plant Sauna, plants are exposed to steam at up to 111.2 degrees Fahrenheit for one to four hours. The results were favorable, finding that steam was effective in protecting plants from various diseases.
But when it comes to spider mites, cold water sprays are the preferred method because the pests love heat and can survive in the Plant Sauna.
