PLATE II 



A. — Cabbage plants showing the relative injury to hardened (H) and nonhardened 

 (NH) plants after exposure for the time given on the label in minutes to a temperature 

 of —3° C. Breaking of the petiole while frozen caused some of the lower leaves of the 

 hardened plants to droop; otherwise these leaves were uninjured. 



B. — Tomato plants showing the relative injury to plants from the greenhouse (NH) 

 and from coldframes (H) after exposure for the time given on the labels in minutes to 

 — 1.5° C. The plants from the coldframes were not frozen. The young leaves show 

 the injury first. 



