In recent years, wind machines to help protect kiwifruit crops from frost damage have been installed in the Bay of Plenty following damaging spring frosts. Unfortunately, their popularity was not anticipated during the formulation of the Western Bay of Plenty District Plan, and noise and resource consents have quickly become an issue. Conflict has arisen between the cost of frost damage to growers and the regional economy and night-time noise from wind machines disturbing sleep. Ruth Underwood reports on the issues and progress with resource consents for wind machines in the Bay of Plenty region.
Most frosts are radiation frosts that occur during a cool night after a clear, fine day.
A low-lying layer of cold air does the damage, but is overlaid by a layer of warmer air. Wind machines or helicopters mix the warm air through the cold air, thus raising the temperature in the orchard and protecting the young flowers, fruit and shoots from frost. Spring frost damage to a kiwifruit orchard at pollination time in late November 1994. Foliage was burnt and many of the flowers fell off or failed to develop properly due to the frost damage. Surviving kiwifruit are often deformed after spring frost damage.