Frost protection in peaches: New model under-tree wind machine tested with and without burners in orchard near Wheatland during winter of 1958–59

Tower mounted wind machines raise orchard temperatures largely by the forced mixing of cold orchard air with the warmer air overhead. However, tests in an almond orchard in the Chico area –in 1955 and 1957–showed that the air jet from tower mounted machines had difficulty in penetrating the tree canopy –typical of deciduous orchards–formed by the intertwining of branches of adjacent trees. Underneath the tree canopy deciduous orchards are relatively open but growers report that most frost damage occurs in the lower part of the trees.