When it comes to protecting crops via insect-blocking netting, you may think that the size of the holes in that netting is the most important factor. According to new research, however, red netting makes an even bigger difference in effectiveness.
Normally, agricultural netting is either black or white, or sometimes blue or green. However, Prof. Masami Shimoda and colleagues at The University of Tokyo wondered if red-coloured netting might be more advantageous. have a similar effect. In order to find out, they experimented with nets of three different colour combinations: red-white, red-black and red-red. Each combo was also tried with three different mesh-gap sizes.
All of these nets - along with traditional black, white and black-white nets of the same mesh sizes - were hung over Kujo leek (aka Welsh onion) crops to protect them from dastardly insects called onion thrips.
As you might expect, all of these different combinations threw off a lot of data. But it became clear that red netting was the winning trick. It was even found that in some cases, red netting with larger holes - through which the insects could physically pass - was still more effective than black or white netting with smaller holes. This finding suggests that the deterrent effect is vision-based, although the exact means by which it works is still proving to be a bit of a head-scratcher.
The good news is that this experiment shows that use of the red netting could ultimately reduce the need for pesticides while simultaneously boosting yields. Better yet, because larger mesh sizes can be used, crops should also benefit from increased exposure to sunlight and better airflow, and therefore be less likely to develop fungal infections.
A paper on the research was recently published in the journal Scientific Reports.