You can have long strips, which are reflecting sunlight & make vibrating sound on air current. Install them above your vegetable crop across the field. This is the chepest way to diverse them & is not harmful to them also.
For sure. This is also a subject of research at Universidade Federal de Viçosa, Brasil. So, we will measure objectively the results. Please, for academic reasons, let me know if your solution is described in the literature. Thanks again, Milind Mohite.
No, this is a common practice developed at the farm itself. Erlier we used to use audio cassets ribbons then we started to make ribbons from waste gift wraps only with reflecting colours. but do not use stripes having shades of yellow colour.
Shades of yellow color are radient and thye can attract attention of any bird or vector from very long distance. If you consider a bird eye view or Google earth view you can easily mark or identify things or structures which are appearing in the shades of yallow colour. Thats the reason how birds know that where to search food and it is ready for harvest.
Another example; when corn fields are near its harvest only at that time birds cause problem now what is the colour of the field from top angle, What is a colour of a fruit when it mature. Most of the times it is in the shades of yellow. so to achieve a repellent effect, the colour of a repellent should'n be attractive to them.
And that is the only reason we make sticky traps with yellow colourd sheets only.