Step #4 Choosing high quality longleaf pine seedlings

Part C; Visually Grading Containerized Longleaf Pine Seedlings (go back)

Containerized longleaf pine seedlings should be visually graded using the following criteria:

Needles:

PREFERRED seedling needles are:

•dark green in color

•6 to 10 inches after being clipped or 8 to 12 inches unclipped

•many needles fascicles present

See pictures of quality needles here

CULL seedlings if needles are:

•yellow to black which indicates poor vigor or a dying seedling

• less than 4 inches in length

•if no needles fascicles are present

See pictures of needles that should be culled here

Roots:

PREFERRED seedling roots are:

•root-collar diameters that are 1/4 inch or larger

•roots that are light brown in color and have numerous white tips

•roots with the presence of mycorrhizae

See pictures of quality roots here

CULL seedlings if roots are:

•root-collar diameters that are less than 3/16 inch

•a large portion of the roots are black and/or the cambium is brown when the black exterior is scraped away with a fingernail.

•any evidence of disease

•any noticeable amount of root spiraling in the container

See pictures of poor roots here

Plug Firmness:

PREFERRED seedling plugs:

•stay intact when extracted and during handling

•remain firm when held out horizontal.

See pictures of quality seedling plugs here

CULL seedling plugs:

•that have lost potting soil

•"flop" over when held horizontal

See pictures of plugs that would cause seedlings to be culled here

Plug Moisture:

PREFERRED plugs:

•have always remained damp

CULL plugs if:

•seedling plug is dry

•seedling is so wet that water can be squeezed from plug

Pests:

PREFERRED plug is without pests:

•no competing weeds, insects or animal damage is present

CULL plug that have pests:

•weeds such as willow trees are present

•insect or animal damage is noted

See pictures of pest or pest damage that would cause seedlings to be culled here

Special Considerations: Buyer should specify whether to cull or not:

•Sondereggers (Pinus Xsondereggeri); are naturally occurring longleaf and loblolly hybrids that have some stem elongations in the nursery. Typically less than 1% of a shipped seedling lot are Sondereggers although certain seed lots may have a higher incidence. Although these seedlings typically have good early height growth, they often produce trees of poorer form, greater rust susceptibility, decreased survival rates and decreased fire tolerance when compared to longleaf pine.

See pictures of Sonderegger pine here

•Doubles are plugs that contain two (or sometimes more) longleaf seedlings. Research has shown that (short term) survival is somewhat higher in doubles. However, short-term growth may be reduced in doubles by up to 50%.
See pictures of double trees per plug here

To find information on grading bare root longleaf pine, click here

For additional reference material click here