A polishing jig for mounting a working object lens on a polishing apparatus that polishes the concave surface of the working object lens, a conveyor tray for exclusive use for conveying the polishing jig, and a conveying method and a conveying apparatus for conveying the polishing jig or the like with the working object lens held thereon to a working apparatus such as the polishing apparatus. Application of the cytokinins is effective to elicit one or more effects in the resultant plant including reduced apical dominance, increased rate of development of fruiting branches, decreased time to first bloom, increased number of cotton squares formed, thickening of the hypocotyl, reduced rate of leaf wilting, reduced water usage, and increased root development. A single main diaphragm extends radially from an inner end portion to an outer end portion, with the inner end portion being mounted to the lug front on a first side of the lug assembly. The electrical system is modular in design, and includes a series of components that may be connected to one another in a manner that the location of electrical outlet modules may be easily adjusted.