CLIMATE AND KIWIFRUIT CV HAYWARD .1. INFLUENCES ON DEVELOPMENT AND GROWTH

A coherent set of field survey data of vine and fruit development even ts at research orchards and other sites in New Zealand were analysed w ith climate data to investigate the influence of climatic factors in k iwifruit (Actinidia deliciosa) development. The timing of the end of d ormancy was determined by the amount of winter chilling. When sufficie nt chilling occurred the time from dormancy end to budburst was positi vely related to temperature over this period. When insufficient chilli ng occurred budburst dates were determined by the amount of exposure t o low temperature. The duration from budburst to flowering required 41 5-degrees-C days above a base temperature of 7-degrees-C to be complet ed. The climatic requirements for early fruit development are yet to b e established. However, high rainfall after January delayed the attain ment of 5.0% soluble solids (SS). From 5.0% SS onwards the rate of mat uration increased as mean temperatures decreased. The relationships de rived can be used to estimate the dates of development events.