The effect of duration of cold treatment on growth and flowering of liatris

Abstract

Dry corms of Liatris spicata L. "Gloriosa" (gay-feather) were stored at 3-5 deg C for 12, 10,8,6,4 or 2 weeks, before being planted and forced outdoors at 21-25 deg C day temperatures and 10-14 deg C night temperatures. Low-temperature treatment at 3-5 deg C was necessary to obtain satisfactory shoot growth and flowering after planting. The rate of plant emergence, shoot growth and the percentage of flowering increased with increasing duration of cold treatment. The period from corm planting to flowering was inversely related to the duration of the cold treatment, optimum duration resulting in early flowering, more uniform flowering and an increase in length of the inflorescences. The non-cold-treated corms, or those which received inadequate low-temperature treatment, resulted in poor and slow plant emergence, many non-flowering shoots and very slow stem elongation for both flowering and non-flowering shoots.