Frost protection in almonds: Wind machine studies in 1955 frost season indicate protection in mature almond orchards below that obtained in citrus
In the Chico area, almond orchards need frost protection—on the average—six nights a year, two years out of three, with one or two of those nights needing 2F or 3F of protection. Late frosts—in April—generally occur only once in eight years. This year there were about one third more frosty nights than usual, and several of those nights occurred in April. This made it possible to conduct a good series of wind machine tests both when the trees were relatively bare and when they had considerable foliage.