Citrus subjected to freezing temperatures and picked immediately thereafter may show a delay of 10 to 15 days before developing internal injury. The rate of development of freeze damage depends upon the injury sustained, the period of low temperature exposure, and other variables. Factors that influence the amount of freeze injury to fruit at any given time of exposure to freezing temperatures are: (1) the degree of maturity; (2) the minimum temperatures; (3) duration of freezing temperatures; (4) fruit & atmospheric temperatures preceding actual exposure to the freezing temperatures; and (5) the air velocity. Small fruits on the tree are more likely to be frozen than larger ones. Tree condition is the most important feature of the responses of citrus trees to cold weather. Healthy, vigorous trees consistently withstand the cold temperatures better than weak or unhealthy trees. Rootstock and varietal differences within a species are not as important in helping the tree to withstand cold temperatures. More freeze injury occurs on trees that are carrying a crop, and green fruit are more easily injured than mature fruit. (Walton B. Sinclair) - Millet