Factors Influencing Flower Petal Abscission in the Seed-propagated Geranium1

Abstract

Flower petal abscission (shattering) in seed geraniums (Pelargonium X hortorum Bailey) is delayed by low temperature (1-5°C) and ethylene-free air. Naphthaleneacetic acid (NAA) or CO2 (5%) did not delay shattering. Respiration and endogenous ethylene synthesis did not follow a climacteric pattern. A method was devised to test flowers for petal abscission. Variation in petal abscission was found among flowers of 35 cultivars evaluated over a 2-year period.