GROWTH AND FLOWER PRODUCTION OF CONTAINER-GROWN GERALDTON WAX CVV ALBA AND PURPLE-PRIDE AT DIFFERENT LEVELS OF IRRIGATION

The effects of 3 levels of irrigation (25, 50, 75% pan replacement) on growth and flower production were studied on 2 container-grown Gerald ton wax cultivars (Alba and Purple Pride) under field conditions. Wate r deficit during the vegetative phase reduced all vegetative growth co mponents (shoot number, primary stem length, cumulative stem length, l eaf number, crown area) and flower production in both cultivars. Prima ry stem length was reduced by 47% and shoot or flower number by >50% w hen irrigation was reduced from 75 to 25% pan replacement. The respons e to reduced irrigation was more severe in Purple Pride than in Alba. During the vegetative phase, 800-840 mm water or 60-63% pan evaporatio n is required to maximise marketable stems of 90 cm under the conditio ns studied.