Bechar, A., Institute of Agricultural Engineering, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Gan-Mor, S., Institute of Agricultural Engineering, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Ronen, B., Institute of Agricultural Engineering, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel

When a charged cloud of pollen approaches and penetrates a blooming tree, it typically deposits more pollen on the outer flowers than on the inner ones. A method was developed to improve penetration of charged pollen through the tree layers, by means of a previously developed electrostatic pollinator. Corona charging is used to charge the pollen cloud, which is then transported in an air stream. In the present study, an electrostatic ring (ESR) that reduces the amount of free ions and facilitates the penetration of the charged pollen was constructed and tested. An artificial tree was constructed and laboratory experiments were conducted to test and enhance the performance of the device. The results show that although electrostatic charging can enhance pollen deposition 28-fold, the ESR can increase it by a further 46% on a whole tree and by 83% on its internal parts. It was also found that the location of the ESR can drastically influence the amount of pollen deposition: for a given setup, with the ESR located at the electrode edge (0 mm) the pollen deposition was 76% higher than when it was located 40 mm behind the edge. © 2008 Elsevier B.V. All rights reserved.