Abstract
Diversity of frost protection methodology is broad when viewed over a long period. Heating methodology is especially diverse. A rule is apparent: growers used readily available materials. Prunings were burned during frosts at the height of the Roman Empire. A broad spectrum of heater types began to appear in more recent centuries. Wood, charcoal, oil, gas, and other fuels were burned in heaters so diverse in design that one's imagination is staggered. Development in design and management continues in some areas of the world in contrast with local opinions that such methods are of only historical interest. Wind machines of various shapes and sizes began to appear in the early part of the 20th Century in response to concerns about air pollution and labor availability. These solutions include the helicopter. Orchard covers, later row and individual plant covers were tried and found effective. Irrigation, the current choice in citrus, was in use in the form of flooding during the earliest days of the past century. Smudges, fogs, steam, heated irrigation, and windbreaks have been tried and in most cases, used effectively. The probability that a freeze will occur in a particular year is low. Authors have published extensive explanations and models. They have advised use of alarms, forecasts, site selection, satellite images, and networking in conjunction with a recommendation to limit attention to the method du jour. Most authors implied the field of work was mature and additional change seemed unlikely. In a longer view change, at times rapid, is an apparent characteristic of the field. Diversity of methodology and grower ingenuity suggests that change will characterize the future as it has the past. Diversity abounds.
