Container-Grown Ponderosa Pine 

 Seedlings Outperform Bareroot 

 Seedlings on Harsh Sites in 

 Southern Utah 



John P. Sloan 

 Lewis H. Jump 

 Russell A. Ryker 



INTRODUCTION 



Reforestation of ponderosa pine (Pinus ponderosa Dougl. 

 ex Laws.) on the lower elevations of the Dixie National 

 Forest in southern Utah has traditionally been challenging. 

 Replanting has often been necessary, costly, and not 

 always successful. Although this problem is not unique, 

 the low levels of available soil moisture during the spring 

 planting season are probably as critical in the Dixie as 

 anywhere in the Intermountain Region. Until this study 

 was initiated, only bareroot seedlings had been planted. 



Elsewhere in North America, container-grown seedlings 

 have been planted in attempts to improve survival and 

 growth in plantations. There have been other reasons for 

 planting container-grown stock as well: to produce nursery 

 stock faster and with less lead time, to produce some 

 species that are difficult to grow in bareroot nurseries, to 

 achieve greater production and planting efficiencies, and 

 to extend planting seasons (Ball and Brace 1982; Barnett 

 1983; Dickerson and McClurkin 1980; Stein 1974, 1977; 

 Stein and Owston 1976, 1977; Tinus 1976). Operational 

 use of container-grown seedlings, and experimental com- 

 parisons between bareroot and container stock have pro- 

 duced mixed results (appendix A). Results may have 

 varied because in many comparisons the container stock 

 was much smaller than the bareroot seedlings (Tinus 

 1979). Generally the container-grown seedlings have per- 

 formed very well, especially in recent years. 



Several investigators have found that the form of root 

 systems of container-grown trees differs from the form of 

 bareroot seedlings and trees seeded in place. Most natural 

 seedlings of ponderosa pine are characterized by a well- 

 developed taproot, with a few evenly distributed laterals 

 starting just below the root collar (Long 1978; Stein 1978). 

 Stein (1978) calculated the average taproot of natural 

 seedlings to be almost six times longer than the shoot 

 after two growing seasons. Bareroot and container culture 

 affected several root system characteristics, including sym- 

 metry, balance, constriction, coiling, taproot development, 

 and root system deformations caused by planting. In most 

 cases there is little difference in root balance and sym- 

 metry between container-grown and bareroot stock; 

 however, coiling and constriction are more prevalent in 

 the container-grown trees. The bareroot trees showed a 

 much higher incidence of roots bent in the shape of an L, 



a J, or knotted, and had fewer well-developed taproots. 

 These differences are still visible from 4 to 7 years after 

 planting (Long 1978). Preisig and others (1979) found 

 more variability in the root form of planted Douglas-fir 

 (Pseudotsuga menziesii [Mirb.] Franco) bareroot seedlings 

 than container-grown seedlings; but seedling height was 

 not related to differences in root system morphology for 

 trees 5 to 8 years old. 



In container-grown stock, root system deformation is 

 largely affected by the size and design of the container. 

 But with bareroot stock the planter largely determines the 

 root configuration. Budy and Miller (1984) found that after 

 10 years the container still influenced the root form and 

 number of lateral roots of Jeffrey pine (Pinus jeffreyi 

 Grev. and Balf.). Similar comparisons of root form have 

 been documented for lodgepole pine, white spruce (Picea 

 glauca [Moench] Voss), Douglas-fir (Van Eerden 1978), 

 lodgepole pine (Pinus contorta Dougl.) and white spruce 

 (McMinn 1978), and Douglas-fir and western hemlock 

 (Tsuga heterophylla [Raf.] Sarg.) (Arnott 1978). Van 

 Eerden (1978) concludes that, although root deformations 

 occur with both container and bareroot seedlings, they do 

 not inevitably lead to plantation failure. Root systems 

 repair themselves and in time acquire a nearly natural 

 habit. 



Buchanan (1974) reports mixed results in comparing 

 bareroot ponderosa pine with seedlings grown in Spencer- 

 Lemaire Rootrainers, Styroblocks, Conwed tubes, and peat 

 blocks. Overall, seedling survival with Styroblocks and 

 Rootrainers was close to that of bareroot. Conwed tubes 

 and peat blocks had lower survival. 



One and 2 years after planting, survival and growth of 

 container-grown ponderosa pine seedlings was equal to or 

 better than that of seedlings grown in Conwed tubes, Jiffy 

 pots, and Styroblocks planted on the Great Plains (Hite 

 1974). Although not all field performance showed signifi- 

 cant differences, Hite saw an average overall gain in sur- 

 vival of about 20 percent from the use of container-grown 

 seedlings. 



This report presents the results of a field comparison 

 between containerized and bareroot ponderosa pine seed- 

 lings on the Dixie National Forest after five growing 

 seasons. The administrative study was undertaken by the 

 Dixie National Forest with help from the Intermountain 

 Research Station. 



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