A simple yet effective gadget that reflected light helped this farmer to prevent birds from damaging his fruit.
On Mr. Manie van Zyl’s farm Plaatkop the birds used to pick off the apricot flowers and eat the fruit every year. Traditional scarecrows, like the boom canon or die doll with the hat on, just didn’t work.
Manie noticed that the birds were sensitive to light flashes and a few years ago he started experimenting to get the whole spectrum of rainbow colours in. First he made a prism of Perspex, which he filled with water. He got the colours when the sun shone on it, but there were several problems with making it watertight and getting the angle right.
Then he got the idea to make something that turned or spinned, but for this he needed a battery and electrical motor. So he designed a device that spins in the wind and it works brilliantly. He bolted three arms to an old electric polisher’s spinning disc and on each arm, a stainless steel bowl. Each bowl has a diameter of 16 cm and serves to catch the wind.
The disc with the bowls was attached to the top of a pole and a light breeze causes it to spin.
Then he realised that a CD has all the colours of the rainbow when it spins around in the sun. The CD’s were attached to the back of the bowls and it worked like a charm.
The cost of the entire device was about ZMK16 for the three bowls. The other parts were found amongst the scrap iron on the farm. Manie says one needs two of these devices – one on the eastern side and one on the western side of an orchard.