VEGETATIVE PROPAGATION OF CONIFERS: IV. EFFECTS OF CANE SUGAR, ETHYL MERCURIC PHOSPHATE, AND INDOLYLACETIC ACID IN TALC DUST ON THE ROOTING OF NORWAY SPRUCE

Abstract

Norway spruce cuttings collected in November from the upper part of the tree were treated with a series of talc dusts containing indolylacetic and naphthylacetic acids, each at 0, 1000, and 5000 p.p.m., combined with cane sugar at 0 and 10%, and ethyl mercuric phosphate at 0 and 50 p.p.m., and propagated in a greenhouse. Indolylacetic acid at 1000 p.p.m. increased rooting by about 10% to 42.5%, three months after planting, but at 5000 p.p.m. reduced it significantly. Naphthylacetic acid reduced rooting at both concentrations. Indolylacetic acid increased the length of root per rooted cutting. Sugar in combination with indolylacetic acid inhibited the increase in root length caused by the hormone alone; organic mercury alone or in combination with indolylacetic acid reduced root length, but sugar and mercury in combination exerted no greater inhibition than either alone.Mean root length was affected only by indolylacetic acid, which increased it.