Improvement in kiwifruit storage life caused by withholding early-season irrigation

Abstract

We investigated whether irrigation can affect the storage potential of kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson). Two experiments were carried out on mature kiwifruit vines growing in a deep silt loam near Gisborne, New Zealand. Experiment 1 (1990/91) mainly compared the effects of irrigation applied to replace different fractions of the shortfall between the weekly totals of potential evapotranspiration and rainfall. It also included a treatment in which early-season irrigation was withheld. Experiment 2 (1991/92) compared the effects of withholding irrigation at different times during the season. Fruit firmness was measured by penetrometer at intervals during storage. Withholding irrigation for the entire season improved fruit firmness during storage, but was accompanied by a significant depression in fruit size. Withholding irrigation until midsummer resulted in only mild water stress (fruit size was unaffected) but increased by c. 30 days the time taken for the firmness of stored fruit to decrease to 1 kgf or 0.2 MPa (the critical value for market acceptability). The mechanisms by which irrigation affected fruit storage properties are unclear. © 1996 Taylor & Francis Group, LLC.