The Darwin string thinner is attached to the front of the tractor. The Bonner is in the background. Mechanical thinning equipment has been tested for several years during bloom on apples and soft fruits, such as peaches and nectarines, but is now being tested prebloom for cherry thinning. Two mechanical string thinners are being studied: the Darwin, which is commercially available in Washington State through Blueline Manufacturing of Moxee, and a prototype of the Bonner, which was developed at the University of Bonn in Germany. The Darwin, which has a single spinning spindle with cords, is most suited to a […]