Climate and kiwifruit cv. ‘Hayward’ 2. Regions in New Zealand suited for production

Abstract

Abstract Matching crops to climate is an important activity for planning production. Three important climatic factors were identified as being important determinants of kiwifruit (Actinidia deliciosa ’Hayward’ (A. Chev) C.F. Liang et A.R. Ferguson) distribution: winter chilling; growing season thermal time; and annual rainfall. Indices for each of these factors were developed to enable mapping of the most suitable areas for kiwifruit production. These were May‐July temperatures of 11°C or less as the optimal winter chilling requirement, a thermal time accumulation of 1100 degree‐days above 10°C from October to April, and an annual rainfall of 1250 mm or more. Apart from Northland, all the traditional areas of kiwifruit production have a suitable climate. However, there are substantial areas of inland Bay of Plenty to Rotorua, the Waikato, north Taranaki, and northern Hawke's Bay where the climatic requirements are also satisfied. A high frequency of extreme winds may be an additional limiting factor in some of these regions, such as Taranaki. The total area of suitability is enlarged if irrigation is available, particularly in the southern North Island and central Marlborough. Within this climatic range the estimated dates for the average end of dormancy and 50% flowering are spread over 4 weeks, and estimated budburst dates over 11 days. Although use of average climate data to describe kiwifruit distribution provides a valuable first‐order assessment, it would be desirable to incorporate analyses of climate variability in future studies of this kind.