64 to 98 percent. The survival differences are statistically 

 significant on four of the five sites. Mammoth Cave is the 

 only site where bareroot stock survived as well as the 

 container-grown seedlings. The biggest difference came at 

 Dave's Hollow, where container-grown trees outsurvived 

 bareroot trees by 20 percent. Dave's Hollow and Mam- 

 moth Creek Road sites had the lowest overall survival; 

 Allen's Canyon and Mammoth Cave showed the best sur- 

 vival; Wilson Peak was in between. 



Mean height growth on the Mammoth Cave (basalt soil) 

 and Wilson Peak sites was similar for containerized and 

 bareroot trees. But, the height growth of containerized 

 stock was significantly better than that of the bareroot 

 stock on the other three sites. Dave's Hollow showed the 

 biggest difference as well as the poorest overall growth. 

 The best mean growth was measured at Mammoth Cave. 



When we excavated a sample of trees 5 years after 

 planting, we found a consistent difference in root form 

 (fig. 2). The root systems of the containerized trees still 

 showed a large mass of roots in the original form of the 

 container plug. From this plug, some lateral roots came 

 out the side but most grew out the bottom. When com- 

 pared to the containerized stock, the bareroot root sys- 



tems often did not have as much mass in the upper 12 

 inches of soil and assumed more of a bell shape. 



Table 4 shows the mean rooting index for three root 

 zones. Root zone 1 is to 4 inches (0 to 10 cm) from the 

 ground surface. Root zone 2 is from 4 to 8 inches (10 to 

 20 cm), and zone 3 is in the 8- to 12-inch (20- to 30-cm) 

 layer. Even though containerized and bareroot root 

 systems are somewhat different in shape, this measure- 

 ment reveals relatively little difference in total root 

 system in the first 12 inches (30 cm) of soil. 



The root index showed trees on the Mammoth Cave site 

 to have more roots in the first 4 inches of soil than on the 

 Dave's Hollow site. The other sites were not different (a 

 = 0.05). In the 4- to 8-inch layer, Wilson Peak seedlings 

 had more roots than Mammoth Cave. At 8 to 12 inches 

 from the surface, Wilson Peak was again the best and 

 Mammoth Cave was the worst, but there were also several 

 other differences. 



Shoot borer damage to the terminal buds was extensive 

 between the third and fifth growing seasons. The insects 

 did not prefer either container-grown or bareroot seed- 

 lings, but there was a difference between sites. The 

 Mammoth Cave and Wilson Peak sites showed the most 



Figure 2— After five growing seasons, the root system forms of container and bareroot 

 ponderosa pine seedlings still show obvious differences. The bareroot tree (left) is shaped 

 like an expanding triangle. The container-grown seedling still Iras the original plug shape 

 with roots growing out of the bottom. These trees were excavated near Wilson Peak in the 

 Dixie National Forest in September 1985. 



4 



