CLIMATE AND KIWIFRUIT CV HAYWARD .2. REGIONS IN NEW-ZEALAND SUITED FOR PRODUCTION

Matching crops to climate is an important activity for planning produc tion. Three important climatic factors were identified as being import ant determinants of kiwifruit (Actinidia deliciosa 'Hayward' (A. Chev) C.F. Liang et A.R. Ferguson) distribution: winter chilling; growing s eason thermal time; and annual rainfall. Indices for each of these fac tors were developed to enable mapping of the most suitable areas for k iwifruit production. These were May-July temperatures of 11 degrees C or less as the optimal winter chilling requirement, a thermal time acc umulation of 1100 degree-days above 10 degrees 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 Roto rua, the Waikato, north Taranaki, and northern Hawke's Bay where the c limatic requirements are also satisfied. A high frequency of extreme w inds may be an additional limiting factor in some of these regions, su ch as Taranaki. The total area of suitability is enlarged if irrigatio n is available, particularly in the southern North Island and central Marlborough. Within this climatic range the estimated dates for the av erage end of dormancy and 50% flowering are spread over 4 weeks, and e stimated budburst dates over 11 days. Although use of average climate data to describe kiwifruit distribution provides a valuable first-orde r assessment, it would be desirable to incorporate analyses of climate variability in future studies of this kind.