Extension of flowering period of fall-planting geophytes for landscape planting by temperature pretreatments of bulbs and corms

Abstract

Corms of crocus(Crocus medius Balb.)and bulbs of daffodil(Narcissus cyclamineus DC)and muscari(Muscari armeniacum Leithl. ex. Bak)were subjected to various temperatures for different periods before planting and planted in open field in fall. Exposure of crocus corms to 20°C stimulated their flower bud development and flowering, while exposure to 30°C delayed them. In daffodil and muscari, exposure of bulbs to 9°C filled their chilling requirement for inflorescence development resulting in early flowering. By combining some storage schemes, these geophytes exhibited ornamental value successively; from November to February in crocus and from January to April in daffodil and muscari. The longevity of flowers bloomed in winter was greatly improved as compared with that bloomed in fall and spring.