A prototype for mechanical distribution of beneficials

The research aim was to investigate natural enemy distribution using an innovative prototype. It was designed to mechanically release Phytoseiulus persimilis Athias Henriot and Orius laevigatus (Fieber), commonly employed in biological control programs for protected vegetable crops. The beneficials were placed with the carrier material inside the bottles into a hopper with an adjustable product dispenser. The product descends onto a revolving disc (d = 20 cm) driven by a DC motor. Currently, the prototype weighs about 4 kg and is set on a one-wheeled frame. The height of the prototype is adjustable in relation to plant height. Two long handles ease work between cultivated rows. Several trials were carried out under laboratory conditions to define parameters and improve its components for work in the field. Throw direction and distance, distribution quantity, feed-rate and vertical throw were examined. Subsequently, field trials were carried out in greenhouses with pepper crops to compare mechanical and manual distribution for the same product quantity. The results show that the metering and distribution system of the prototype proved suitable for organic plant protection treatments. Furthermore, effective work time is shorter with mechanical rather than manual distribution.