Killing of Plant Tissue by Low Temperature 



239 



Kind of Root 



Location 



of 



Root 



Two-year Ben 

 Davis apple 

 roots 



One-year 



French apple 

 seedlings 



One-year 



French apple 

 seedlings 



11 inches be- 

 low surface.. 



,3 in.... 6 in.... -10 



One-year 



French apple 

 seedlings 



One-year 



Japan pear 

 seedlings. . . 



One-year 

 Japan pear 

 seedlings. . . 



One-year 

 Japan pear 

 seedlings. . . 



Angers Quince 

 roots 



.4 in.... 



,4 in... . 



12 in.... 



11 in... 



-10 



-10 



35 in... 8 in.... I -10 



.4 in.... 11 in.... -10 



.4 in.... 10.5 in... -10 



35 in... in.... -10 



5 in. 



-7 



Results 



Cortex and cam- 

 bium injury 

 throughout. 

 No injury in 

 sap wood. 



Cambium in- 

 jury in last 11 

 in; cortex in- 

 jury in last 6 

 in; pith injury 

 in last 2 inches. 



Cambium in- 

 jury through- 

 out; cortex in- 

 jury in last 10 

 in; sap wood 

 injury in last 4 

 inches. 



Cambium slight- 

 ly injured 

 throughout; 

 cortex injury 

 in last 3 inches. 



Cambium in- 

 jury through- 

 out; cortex in- 

 jury in last 7 

 inches sap 

 wood injury 

 in last 3 inches. 



Cambium in- 

 jury through- 

 out; cortex in- 

 jury in last 8 

 inches; sap 

 wood injury in 

 last 2 inches. 



Cambium in- 

 jury through- 

 out; cortex in- 

 jury in last 7 

 inches; s a p 

 wood injury in 

 last 4 inches. 



Cortex slightly 

 injured. 



