Changing the color of commonly used agricultural nets can reduce the damage of insect infestations to the Kujo leek fields.
According to a new study, red nets are more likely to keep away common agricultural pests than typical black or white nets.
The researchers experimented with the effect of red, white, black, and a combination of color nets on stopping onion thrips from eating nine leeks, also known as Welsh onions. In laboratory and field tests, red netting is significantly superior to other colors in stopping insects. In addition, in field trials, onion crops partially or fully covered with red nets required 25-50% less insecticide than fields that were completely uncovered.
Newbie Assistance Program Changing the farm net from black or white to red can help reduce the use of pesticides and their associated negative impact on the environment, while supporting more sustainable and efficient agricultural practices.
Pests are a nightmare for any gardener. As soon as the fresh buds appear, they are covered in aphids, beetles, and other bugs looking for a tasty snack.
While synthetic pesticides are widely used to control pests in gardens and crops, many are known to cause damage to the natural environment by seeping into soil and water sources and poisoning plants, wildlife, and harmless insects. Some pests have also developed resistance to chemicals, so farmers have run out of choices about what to use and need to apply more often.
Agricultural mosquito nets are another way to protect crops and reduce the use of pesticides. As you pass by orchards or vegetable patches, you may see typical white, black, or blue mesh greenhouses. Like mosquito nets on beds, they physically prevent insects from entering crops. It makes sense to think that the most important feature of these nets is the size of the holes in the grid. The smaller the hole, the smaller the bugs that the insect must enter. However, a team of researchers from the Kyoto Prefectural Forestry Fisheries Center and the University of Tokyo found that the color of the net may play a more important deterrent role.
We tested red nets with mesh sizes larger than insect bodies, but still more effective than traditional black or white nets with smaller mesh sizes. This kind'Optical pest control'Rely on the nature of insect color vision to repel pests," explains Professor Masami Shimoda of the Graduate School of Agriculture and Life Sciences at the University of Tokyo. "Most insects don't have red photoreceptors in their eyes, and they have a hard time seeing red, so we thought it was strange that an invisible color could be used to control them.
The team focused on one pest, the onion thrips (thrips tabaci). The insect is highly resistant to pesticides and causes widespread damage to a range of important crops around the world by eating them and spreading harmful viruses. The researchers worked in three mesh sizes (2 mm, 1 mm and 0.).8 mm) was tested with three color combinations of red nets (red-white, red-black, and red-red). They also tested typical black, white, and black-and-white combination nets of the same size, both in the lab and in the field.
Overall, all nets containing red fibers performed significantly better at stopping onion thrips than black or white nets. In a second outdoor trial, the researchers tested the effectiveness of the red net at different levels of coverage: no coverage, full coverage, top only, and side only. Due to an outbreak of onion thrips in the area, pesticides were used. Fully covered plots require minimal pesticides and produce onions with high commercial value. Only ceiling or side covered plots require an additional application of insecticide compared to fully covered plots. Red-net plots reduced the number of pesticide applications by 25-50% overall compared to completely uncovered plots.
These new red nets are more expensive than pesticides, but they are economical because they can last for years. They are also very effective in controlling pests without the need to spray pesticides," Shimoda said. "My dream is that in the future we can make red nets that don't look red – at least not red to the human eye, but they have the same effect on pests. Hopefully, this will reduce manufacturing costs and we can find ways to improve durability.
In addition to reducing onion thrips, another advantage of red nets is that they can have larger holes because they rely on color rather than mesh size. This improves air permeability, reduces the chance of fungal infections, and improves access to sunlight. In addition, the temperature inside the greenhouse does not become as high due to better airflow, making it easier for farmers to work indoors.
If consumers are interested in this sustainable agriculture and use fewer chemical pesticides, I have no doubt that this simple yet effective solution will spread widely," Shimoda said. "My family has been full-time farmers since the Edo period (17th century), and I myself enjoy growing vegetables and fruits on a small scale, although pests can make it challenging. It's well worth growing your own fruits and vegetables and eating them fresh.
Reference: "Advanced Methods for Insect Nets: Red Mosquito Nets for Sustainable Agriculture" by Susumu Tokumaru, Yoshiaki Tokushima, Shun Ito, Terumi Yamaguchi, and Masami Shimoda, February 14, 2024, Scientific Report.
doi： 10.1038/s41598-024-52108-1