Malformation of roses due to drought stress

Rose plants were subjected to the same degree of drought stress but at different stages of development. Irrigation was suspended for a certain period according to the soil moisture deficit and the leaf stomatal resistance. Rose flower development was most sensitive to drought stress prior to petal and stamen initiation. At those stages, drought stress affected the quality of the flowers (reduction in the number of well-formed petals and in length of the flower bud). Application of drought stress during stamen initiation (or during petal initiation in winter) caused abortions and malformations of the flower bud once the stem had elongated to approximately 15 cm. Such malformed buds had no carpels, and stamens were tightly packed on the center of the receptacle. (C) 2003 Elsevier B.V. All rights reserved.