., 2006 ). Pine bark has been observed to be a suitable medium for plant growth ( Pokorny et al., 1986 ), especially in southern nurseries, and is accepted as the primary component of most soilless substrates in container production ( Bilderback et al
Kristopher S. Criscione, Jeb S. Fields, Jim S. Owen Jr., Lisa Fultz, and Edward Bush
Jeb S. Fields, Kristopher S. Criscione, and Ashley Edwards
management strategy easily into production. It is hypothesized that a single screen could be used to divide a pine bark substrate into fractions to achieve stratification. Therefore, the objective of this study was to evaluate the growth effects of a nursery
T. H. Yeager and J. E. Barrett
Polyvinyl chloride columns (4 × 15 cm) containing by volume either 2 pine bark : 1 moss peat : 0 sand, 2 pine bark : 0 moss peat : 1 sand, 0 pine bark : 1 moss peat : 1 sand, or 2 pine bark : 1 moss peat : 1 sand amended with 3 kg m-3 of 32P-superphosphate (8.7% P) were leached daily with 16 or 32 ml of deionized water (pH 5.5) in 1 hour. Irrigation rate did not affect 32P leaching nor was there a media rate interaction or difference in the percentage total 32P and dissolved 32P leached. Medium 2:1:1 had the greatest percentage (76%) of 32P leached during the 3-week experimental period, however, 55% of the 32P amendment leached from each medium the 1st week.
Debalina Saha, S. Christopher Marble, Brian Pearson, Héctor Pérez, Gregory MacDonald, and D. Calvin Odero
indaziflam ( Jhala and Singh, 2012 ). Table 2. Retention of preemergence herbicides in 2 inches (5.08 cm) of pine bark mulch following 1.5-inches (3.81 cm) of irrigation. Physical property analysis. Particle size analysis showed that PS was mostly composed of
Brian E. Jackson, Robert D. Wright, and Michael C. Barnes
al., 2006 ; Fain et al., 2006 ; Laiche and Nash, 1986 ; Wright and Browder, 2005 ). Although pine bark (PB) is a product/component of pine trees, for the purpose of describing pine wood-based substrates that have recently been investigated, it is
Jeb S. Fields, James S. Owen Jr., and Holly L. Scoggins
experimental pine bark-based substrates used to produce Hydrangea arborescens plants. Substrates included conventional pine bark (unprocessed bark, UB), bark particles that pass through a 4.0-mm screen (fine bark, FB), bark particles that do not pass through
Jeb S. Fields, William C. Fonteno, and Brian E. Jackson
(OM) components in them. These components, primarily composed of sphagnum peatmoss and pine bark, can become hydrophobic, thus reducing wettability ( Dekker et al., 2000a ; Michel et al., 2001 ). The molecules of OM contain many organic acid
Cheryl R. Boyer, Glenn B. Fain, Charles H. Gilliam, Thomas V. Gallagher, H. Allen Torbert, and Jeff L. Sibley
these large containers are composed primarily of aged pine bark and Canadian sphagnum peatmoss blends. These materials provide support for plant growth structurally as well as providing a nutrient and water reservoir. Pine bark (PB) and peatmoss (PM) are
Janet C. Cole and John M. Dole
These studies were conducted to determine the effect of 1) temperature on P leaching from a soilless medium amended with various P fertilizers, 2) water application volume on P leaching, and 3) various fertilizers on P leaching during production and growth of marigolds (Tagetes erecta L. `Hero Flame'). Increasing temperature linearly decreased leaching fraction; however, total P leached from the single (SSP) or triple (TSP) superphosphate-amended medium did not differ regardless of temperature. Despite a smaller leaching fraction at higher temperatures and no change in the total P leached, P was probably leached more readily at higher temperatures. More P was leached from the medium amended with uncoated monoammonium phosphate (UCP) than from the medium containing polymer-coated monoammonium phosphate (CTP) at all temperatures, and more P was leached from UCP-amended medium at lower temperatures than at higher temperatures. More P was leached from TSP- than from SSP-amended medium and from UCP- than from CTP-amended medium regardless of the water volume applied, but leachate P content increased linearly as water application volume increased for all fertilizers tested. Plant dry weights did not differ regardless of P source. Leachate electrical conductivity (EC) was lower with TSP than with SSP. Leachate EC was also lower with CTP than with UCP. A higher percentage of P from controlled release fertilizer was taken up by plants rather than being leached from the medium compared to P from uncoated fertilizers.
Research reports documenting phosphorus leaching from soilless container media has changed commercial nursery phosphorus fertilizing practices. However, rhododendron growers are concerned that phosphorus levels are adequate as plants begin setting flower buds in July and August. Medium solution of 10 to 15 ppm P are recommended. Five replicated leachate samples were collected from 6 phosphate sources for 11 weeks following surface application to 2 container grown rhododendron cultivars. Each fertilizer source wax blended to an analysis of 14.0N-11.2P-5.0K except a 14.0N-0P-5.0K control. Phosphate sources included Diammonium Phosphate, Triple superphosphate, Sulfur coated Diammonium Phosphate, Sulfur coated triple superphosphate, and a commercial rhododendron sulfur coated fertilizer. With the exception of control, all treatment leachate phosphorus levels ranged from 180 to 145 ppm two days and 85 to 75 ppm one week after application. All sources ranged from 45 to 10 ppm weeks 2-5 and were lower than 10 ppm weeks 7-11. Leachate levels of the control were below 10 ppm at all sample times. Bud set and foliar P levels were different among phosphate treatments, but growth index measurements were not significant.