FROST INJURY TO TOMATOES. 9 



(4) No consistent difference was found between the freezing points 

 of ripe and practically fuU-growL green tomatoes of the same 

 varieties. 



(5) No consistent difference in freezing points of early and late 

 varieties was found. 



(6) Six average tomatoes were undercooled in the laboratory to 

 22.63° F. before freezing commenced. The freezing point was 30.64 

 F. 



(7) Tomatoes can be undercooled below their freezing point and 

 if undisturbed may remain without freezing for a limited time; 

 however, at any moment while undercooled a slight jar is liable to 

 cause freezing. 



(8) The possession of a thick skin with little tendencey to crack is 

 apparently an important factor in the frost resistance of tomatoes. 

 Under field conditions such a covering favors the undercooling of 

 the fruits by preventing inoculation of the tissue from ice formed 

 on the surface. 



(9) The freezing point of ripe parts of a tomato may be slightly 

 lower than for green parts of the same fruit. Tomatoes on the vine 

 freeze on the upper stem end first partly for the above reason and 

 partly because dew, deposits on the upper side and tends to inoculate 

 the surrounding tissues. 



