INFLUENCE OF MUSHROOM STRAINS AND POPULATION-DENSITY ON THE PERFORMANCE OF A ROBOTIC HARVESTER

The effects of mushroom strain, distribution, size, growing angle and flush number on the performance of an experimental robotic harvesting rig are described. The robotic system has three main elements: a machi ne vision system incorporating mushroom location and picking order sel ection algorithms, a computer-controlled Cartesian robot and a special ized mushroom picking end-effector. The picking strategy is based on p icking freely available mushrooms or mushrooms on the outside of a clu mp first. Two series of experiments were conducted; the first using mu shrooms grown in deep polythene bags and the second using mushrooms gr own in shallow plastic trays. The experimental robotic harvester was c apable of successfully picking about 70% of the mushrooms from a growi ng container. Mushroom strain had a significant effect on the picking success of the harvesting rig and there was a higher success rate with larger mushrooms. The success rate was highest (76%) with mushroom st rain Somycel U1. The differences observed between strains were mainly due to differences in the number of mushrooms produced in the cropped area rather than to differences between individual mushrooms from diff erent strains. High densities of mushrooms (which occurred particularl y in the second flush of a crop) resulted in poorer picking performanc e, but the picking performance was not significantly affected by mushr ooms touching each other or growing on the periphery of groups. (C) 19 97 Silsoe Research Institute.