Environmental influences on adventitious rooting in cuttings of non-woody species

Abstract

The environment which supports and facilitates rooting of cuttings has a profound influence on the success or failure of the establishment of a new plant. The purpose of this chapter is to assess the types of variation in environment that are important. The intention is to focus on the entire process of adventitious rooting i.e. to include the preceding pre-cutting period, hereafter designated stock plant, as well as the subsequent post-rooting period which will be called establishment. These two marginal periods have all too often been neglected in the literature concerned with the effects of environmental conditions on adventitious rooting and the effects of various hormonal treatments on this process. Frequently there is a lack of concern for the environmental conditions of stock plants. Also many physiologically oriented papers neglect the fact that adventitious rooting is a means of propagation i.e. the establishment of a new plant. The environment which has received the most attention, judging from the number of research papers, is the rooting period itself. It is also the period where changes in environment have the most pronounced effect on the percentage of cuttings that succesfully form a root system and on the number and mass of roots formed. These effects are, however, greatly influenced by the physiological condition of the stock plant and this in turn affects the extent to which cuttings respond to their immediate environment. The latter defines the `quality' of the cutting.