Growth and flower production of container-grown Geraldton wax cvv. Alba and Purple Pride at different levels of irrigation

Abstract

The effects of 3 levels of irrigation (25, 50, 75% pan replacement) on growth and flower production were studied on 2 container-grown Geraldton wax cultivars (Alba and Purple Pride) under field conditions. Water deficit during the vegetative phase reduced all vegetative growth components (shoot number, primary stem length, cumulative stem length, leaf number, crown area) and flower production in both cultivars. Primary stem length was reduced by 47% and shoot or flower number by >50% when irrigation was reduced from 75 to 25% pan replacement. The response to reduced irrigation was more severe in Purple Pride than in Alba. During the vegetative phase, 800-840 mm water or 60-63% pan evaporation is required to maximise marketable stems of 90 cm under the conditions studied.