Milled Pine Bark Research Articles

Propagation of Blueberry by Softwood Terminal Cuttings in Pine Bark and Peat Media1

Abstract Softwood terminal cuttings of ‘Woodard’ and ‘Tifblue’ blueberry (Vaccinium ashei Reade) rooted best in media containing milled pine bark alone or mixed with equal parts of perlite, compared to sphagnum peatmoss alone or mixed with equal parts of perlite. Percentage rooting, root quality, and percentage marketability of softwood terminal cuttings of Vaccinium ‘Tifton 275’, a complex hybrid of V. corymbosum L. and V. ashei, was unaffected by rooting medium.

Control of Florida Wax Scale On ‘Nellie R. Stevens’ Holly, Alabama, 1981

Abstract ‘Nellie R. Stevens’ hollies growing in full sun (3 gal plastic pots, milled pine bark, peatmoss, and shale, 3:1:1, v/v/v) were treated twice with 3 compounds to determine efficacy in controlling florida wax scale. Foliar sprays were applied to run-off Jul 14 and 21 using compressed air sprayers with Nu-Film 17 as an adjuvant (0.5 pt/100 gal). Each treatment was replicated 3 times (single plant replicate) and arranged in a randomized block design. Efficacy was determined Jul 27 by examining 100°Florida wax scale per plant for mortality and scoring them as living if normally-colored and full-bodied or dead if they were discolored and shriveled or dried.

Deltic 21EC Phytotoxicity Test on Woody Ornamentals, Alabama, 1981

Abstract Foliar applications of Deltic 21EC were applied to 9 container-grown woody ornamental species to evaluate phytotoxicity or ornamentals that might be oversprayed during lawn treatments for flea or tick control. The experiment was conducted oudoors in full sun at the Auburn University Ornamental Horticulture Field Station, Mobile, AL. Treatments were replicated 4 times for each species in a randomized complete block design. Each replicate was a single plant growing in a 1 gal plastic pot filled with a growing medium of milled pine bark and sandy clay, 5:1, v/v. Sprays were applied over the top of the plants to run-off using a hand-pumped, compressed air sprayer equipped with fan nozzle on Jul 14.

Pine bark ‐ phosphorus relationships

Abstract Columns of milled pine bark were leached weekly with 576 ml of distilled water for 6 weeks and leachates collected. Leachate analysis indicated that significant amounts of indigenous P were leachable. When ‘Helleri’ holly were grown in pine bark with no P applied, 0.08 mg of indigenous P was absorbed. Studies were also conducted to determine if pine bark adsorbs P. The amount of P adsorbed by pine bark, as determined by equilibrium solution analysis, ranged from 0 to 9.7 μg per g of pine bark when solutions of P ranging from 0 to 15 ppm were equilibrated with pine bark for 24 hours. P adsorbed, as determined by analysis of the above ashed pine bark following distilled water leaching, ranged from 0 to 5.3 μg per g of pine bark for the 0 to 15 ppm P treatments, respectively.

Electron microprobe analysis of calcium solution penetration into milled pine bark particles

Abstract Pine bark (Pinus taeda L. and P. elliottii Engelm.) pieces, 2.5 to 5.0 cm diameter, submerged in water became saturated more rapidly in a vacuum than at atmospheric pressure. A test was conducted to determine the extent of Ca solution penetration into smaller milled particles and the effect physical structure of particles has on this process. Particles 2.0–2.8 mm diameter were submerged in a solution of 1000 ppm Ca as Ca(OH)2, placed in desiccators and evacuated to 150 mm Hg of tension. At intervals of 24, 48 and 96 hours samples were removed, freeze‐dried, and cut tangentially to expose the internal phloem. Electron microprobe x‐ray analysis initially showed different Ca concentration in peripheral and central zones and indicated that Ca solution had penetrated the particle and saturation was completed within 96 hours. The progression of Ca penetration was uniform from all edges and indicated that the varied structure of bark tissues did not impede water penetration.

Influence of Initial Moisture Content on the Wettability of a Milled Pine Bark Medium1

Abstract Water absorption curves were developed for air dry peat-vermiculite and pine bark media. Data indicated 70-78% of moisture saturation was attained within 5 days with a peatvermiculite medium while 48 days were required to achieve 58-70% saturation with a milled pine bark medium. Increased water absorption of pine bark after 10 days of wetting suggested that a threshold moisture level within the bark particles is necessary if water uptake is to be enhanced. The threshold moisture content was established at 35% (wet wt basis).

The Structure of Processed Pine Bark1

Abstract The external surfaces and internal structures of particles of milled pine bark (Pinus taeda L. and P. elliottii Engelm.) were examined with scanning electron microscopy. Numerous external openings, cracked cell walls and internal cellular connections, that might allow water penetration were observed. Periderm surfaces were without pores, and contained rough surfaces and apparently waxy substances that might resist water penetration or absorption.

Physical and Chemical Properties of Media Composed of Milled Pine Bark and Sand1

Abstract Bulk density (BD) of potting media increased as the percentage of sand was increased in the medium. Because of the “fitting” together of particles, volume of medium mixtures was always less than the total volume of the separate components. Particle size distribution was determined most accurately on a volume basis and was used to identify the potting mixtures. The percentage of medium components (bark or sand) retained on any given sieve size could be determined from BD data. Percolation rate, and cation exchange capacity (CEC) declined as the percentage of sand was increased in the potting mixture. CEC was most accurately determined on a volume basis. Increasing the percentage of sand in the potting medium raised pH from 4.1 to 5.4.

Herbicide-impregnated mulches for weed control in container nursery stock

Isopropyl- m-chlorocarbanilate (chlorpropham), chlorpropham plus p-chlorophenyl- N-methylcarbamate (PPG-124), S-ethyl dipropylthiocarbamate (EPTC), N, N-dimethyl-2,2-diphenylacetamide (diphenamid) and 2,6-dichlorobenzonitrile (dichlobenil) were evaluated for plant tolerance and weed control when incorporated on milled pine bark mulch and applied at a depth of 1.27 cm to five species of container-grown nursery stock. During two seasons, all impregnated mulches except EPTC at 5.6 kg/ha and diphenamid at 5.6 kg/ha provided adequate long-season broadleaf weed control. Similarly, long-season grass weed control was acceptable with all herbicide-impregnated mulches except chlorpropham at 2.2 kg/ha, chlorpropham plus PPG-124 at 2.2 plus 0.4 kg/ha and diphenamid at 5.6 kg/ha. Plant injury appeared on all five species of nursery stock when dichlobenil was impregnated on pine bark mulch at a rate of 13.4 kg/ha.

The Relationship of Several Amended Soils and Compaction Rates on Vegetative Growth, Root Development and Cold Resistance of ‘Tifgreen’ Bermudagrass1

Abstract A greenhouse experiment was conducted to determine the relationship between milled pine bark amended soils (0, 25, and 50% pine bark mixed with soil, by volume), and applied compaction rates (0, 20, 40, 60, and 80 psi) on vegetative growth, root development, and cold tolerance of ‘Tifgreen’ bermudagrass. One-half of the unamended soil and of the pine bark amended soils was also overlain with a 3-inch milled pine bark layer (cushion) in an attempt to absorb compaction forces. Soil compaction significantly reduced top and root development of the bermudagrass. Forty to 60 psi represented the point at which soil compaction became a severely limiting factor in turf growth. A 3-inch surface layer of pine bark offset the value of incorporating pine bark as a soil amendment. Amending the soil with pine bark (up to 50% by volume) increased vegetative growth and root development of turf and delayed the onset of adverse conditions caused by soil compaction. ‘Tifgreen’ bermudagrass recovered best from low temperature (-9.4°C for 5 hr) exposure when grown in soils receiving compaction pressures less than 40 psi and which were amended with 50% milled pine bark, 25% milled pine bark, or were unamended.