Abstract
The development of plant activators has been facilitated by coordinated research on a relatively small number of plant species, of which ornamental geophytes, commonly termed flower bulbs, are a minor group. Nevertheless, in the last few years much data have been collected on induced resistance in ornamental geophytes as a possible mechanism to control plant pathogens in greenhouses, in the field, and in laboratory experiments. The present paper describes and characterizes plant activators that have been used in bulb crops, enumerates their activities, and discusses the complexities of their practical implementation in disease management of ornamental geophytes.