| Seedlings of nine coarse-rooted species - sawtooth oak (Quercus
acutissima Carruth), white oak (Q. alba L.), cherrybark oak (Q.
falcata var. pagodifiolia Elliott), post oak (Q. stellata
Wangenh.), black walnut (Juglans nigra L.), pignut hickory [Carya
glabra (Mill.) Sweet], pecan [C. illinoinensis (Wangenh.) C.
Koch], Chinese chestnut (Castanea mollissima Blume), and common baldcypress
[Taxodium distichum (L.) L. Rich] - were grown for on growing season
in nontreated containers or in containers treated on their interior surfaces
with white interior latex paint containing 100 g Cu(OH)2 /liter.
Seedlings of each species and container treatment were harvested twice:
once after being transplanted from 3.2- to 15.0-liter containers and at
the end of the growing season. Cupric hydroxide-treated containers decreased
the amount of circled, kinked, and matted roots formed at the container
wall-medium interface in all species tested. Plants grown in Cu (OH)2
-treated containers also had altered root dry-weight partitioning. The partitioning
patters were species specific and included 6% to 20% increases in the percentage
of root dry weight in interior vs. exterior portions of the rootball (white
oak, black walnut, Chinese chestnut, and baldcypress), 10% to 21% increases
in the percentage of root dry weight in upper vs. lower halves of the rootball
(sawtooth oak, cherrybark oak, black walnut, and baldcypress), and an increase
in the percentage of primary lateral roots (lateral roots originating from
taproots or roots functioning as taproots) on the upper (proximal) half
of taproots (cherrybark oak, pecan, and baldcypress). Nutrients in leaves,
stems, and roots of sawtooth oak seedlings were analyzed at both harvests.
Seedling grown in Cu(OH)2-treated containers had more Cu in most
plant tissues than nontreated seedling. Also, seedlings grown in Cu(OH)2
-treated containers had higher total Ca and Mg concentrations at transplanting
and higher total N and Zn concentration at the end of the growing season
than nontreated seedlings. |