This study was designed to determine whether trees growing in tall, narrow containers versus regular containers of equal volume, or trees growing in containers coated with cupric hydroxide versus no coating would have a better quality root system, less circling roots, and more biomass production. Ficus (Ficur retusa L. `nitida') and pepper (Schinus terebinthifolius Raddi.) liners were grown for 6 months in the greenhouse in one-gal. containers. Cupric hydroxide coating prevented matting of roots on the side of the root ball in both species and root circling at the bottom of containers in ficus. Pepper trees growing in regular-shaped containers had a higher biomass production versus trees growing in tall containers. Subsequently, trees were transplanted to 3 or 5 gal. containers with shape or coating as described above. For pepper, cupric hydroxide coating versus no coating reduced circling and matting of roots, trees in regular versus tall containers had increased above ground biomass, and trees in 5-gal. versus 3-gal. containers grew more medium and small-sized roots and produced more total biomass.
Ursula K. Schuch and Dennis R. Pittenger
James H. Aldrich and Jeffrey G. Norcini
The response of the root system of `Barbara Karst' bougainvillea [Bougainvillea buttiana (Bougainvillea glabra Choicy × Bougainvillea peruviana Humb. & Bonpl.) `Barbara Karst'] cuttings to 100 g Cu(OH)2·liter-1 in a white latex paint applied to the interior surface of square 66 ml, 120 ml, or 280 ml plastic pots was determined. Cuttings (10 cm long; 3-5 nodes; 2 leaves) were scored on opposite sides and dipped in 6000 mg·liter-1 KIBA for 3 sec. The cuttings were placed in treated or untreated pots that contained a medium of 1 Canadian sphagnum peat: 1 coarse perlite (v/v). The pots were completely randomized in a 3×2 factorial design. The cuttings were rooted under intermittent mist 9 sec·min-1 for 12 hr·day-1 in a greenhouse (20% shade). The number of primary roots, fresh and dry weights, and root quality were determined 15 June. The Cu(OH)2-treated pots resulted in a more compact, well-branched root system and eliminated root circling. However, root fresh weight was reduced by Cu(OH)2 treatment. Pot size influenced the number of primary roots and fresh and dry weights.
Larry J. Kuhns, Tracey Harpster, and Clyde Elmore
SpinOut is a commercial product containing copper hydroxide that is designed to prevent the development of circling roots in container grown ornamentals. Our objective was to determine the effect of two root-inhibiting herbicides (oryzalin and trifluralin) on the development of circling roots in container grown ornamentals when painted onto the inside surface of the containers or on stakes inserted around the walls of the containers. Rooted cuttings of wintercreeper euonymus (Euonymus fortunei Hand.-Mezz) were planted in a 1 peat: 1 perlite: 1 soil mix on 8 to 10 Feb. 1995. There were 16 containers for each of 20 treatments. Eight were rated for circling roots then harvested 17 to 22 May, and eight were rated and harvested 6 to 7 July 1995. Root circling was rated on a scale of 1 to 5, with 1 indicating no circling roots and 5 indicating many circling roots. Following harvest stem growth was measured and the dry weights of the roots, stems, and leaves were determined. Treated stakes did not prevent circling roots Trifluralin in Vapor Gard reduced the amount of circling roots, but not to acceptable levels. Trifluralin in latex paint was ineffective at 0.5%, slightly reduced the development of circling roots at 2%, and at 4% reduced circling rooting to the same extent as the SpinOut. Surflan at 0.5% in Vapor Gard reduced the development of circling roots to the same extent as the SpinOut. All other rates of Surflan, in both carriers, almost totally eliminated circling roots. There were no significant differences in root weight or total plant weight among any of the treatments at either date of evaluation.
James A. Schrader, Gowrishankar Srinivasan, David Grewell, Kenneth G. McCabe, and William R. Graves
assessed for presence of root circling. Presence of root circling was a visual assessment of the presence or absence of roots that were touching the inside of the container and had growth that had turned and followed the contour of the container wall. Root
root quality of container-grown plants Root circling or malformation is an inherent problem in container-grown nursery crops. Elimination of root circling via application of copper hydroxide to interior surfaces of containers has proven to be effective
Catherine A. Neal
were painted with latex paint containing copper hydroxide (Spinout; Griffin Chemical Corp., Valdosta, GA) to prevent root circling. The substrate was a commercial nursery mix (Conrad Fafard Inc., Agawam, MA) composed of 80% pine bark and 20% peat
Susmitha S. Nambuthiri and Dewayne L. Ingram
landscape establishment and could cause root circling, leading to restricted water and nutrient movement and ability to adequately anchor. A high carbon-to-nitrogen ratio (138:1) of peat containers (S. Nambuthiri, unpublished data) may have limited their
Susmitha Nambuthiri, Amy Fulcher, Andrew K. Koeser, Robert Geneve, and Genhua Niu
certain types of containers would need to be removed or manually broken apart and incorporated into the soil before the bed can be replanted. Slow container degradation posttransplanting could cause root circling, leading to restricted water and nutrient