Pinus Radiata Bark Research Articles

The biology ofRoptrocerus xylophagorum [Hym.: Torymidae], with a note on its taxonomic status

The biology of the bark beetle parasitoidRoptrocerus xylophagorum (Ratzeburg) from Georgia, U.S.A., was studied under controlled conditions in Australia. Parasitoids were presented withIps grandicollis Eichhoff in the isolated bark ofPinus radiata D. Don. Females lived up to 24 days at 24°C, and could parasitize up to 11 hosts in a single day. Usually only 1 egg was laid on each paralyzed host. Both larvae and pupae were parasitized, but the former appeared to be preferred. The species was arrhenotokous, and tended to produce more males when parasitizing smallerIps larvae. Males and females required 158Do and 179Do respectively, above a threshold of 13.8°C, to complete development, and their size was dependent on the host stage.

Particle size and the physical properties of growing media for containers

Abstract The effects of particle size distribution on the physical properties of growing media based on Pinus radiata bark were measured in laboratory experiments. Varying the proportions of particles larger than 0.5mm had little effect on air‐filled porosity and ability to release water between 1 and 10kPa suctions. Particles in the 0.1 to 0.25mm range decreased air‐filled porosity and increased water release to a greater extent than did either those in the 0.25 to 0.5mm range or those smaller than 0.1mm. Pine bark fractions generally had a greater ability to supply water at suctions below 10kPa than did sand of similar size. Guidelines for formulating media with differing abilities to supply air and water are given.

Wetting properties of dried-out nursery container media

Container mixes consisting of Pinus radiata bark and brown coal or clay loam soil have poor wetting properties when they are dry, because of the shrinkage of all three and the hydrophobic nature of dry pinebark. The wettability of coarse sand, which is independent of its dryness, is quantitatively transferred to container mixes in proportion to the amount used.

The effect of Pinus radiata bark toxicity on the early growth of plants in containers

Fresh Pinus radiata bark will impair the growth of seedlings and struck cuttings of some species, e.g., Impatiens linearifolia, Coleus blumei cultivar ‘Golden Gem’, Engenia cyanocarpa, Hymenosporum flavum and Chrysanthemum morifolium ‘White Sands’; but not of Monstera pertusa, Camellia sasanqua ‘Lucinda’, Rhodondendron ‘Sir Robert Peel’ or Pilea cadierei. Partial elimination of the phytotoxicity was as effective as complete elimination in allowing normal growth of the plants. For sensitive species, the presence of the propagating mixture around the root systems at the time of planting helped to nullify the effects of the toxins. Bare-rooting the plants exposes them to a maximum set-back. The percentage of bark in a mixture also influenced the extent of the phytotoxicity.

Molecular Size Distribution of Radiata Pine Bark Extracts and its Effect on Properties

Molecular Size Distribution of Radiata Pine Bark Extracts and its Effect on Properties

Polyphenolic Extractives of Pinus radiata Bark

Polyphenolic Extractives of Pinus radiata Bark

Microbial Degradation of Condensed Tannins

A strain of Penicillium adametzi Zaleski was isolated from enrichment cultures with condensed tannins as the carbon source. Low-molecular-weight condensed tannins, extracted and purified from Pinus radiata bark, were used as substrates for quantitative growth measurements on this fungus in defined culture conditions.

The hydrophobic properties of bark extractives

The hydrophobic properties of benzene-soluble extractives from the bark of Pinus radiata were studied by determining the water-solid-air contact angle and the resistance to water penetration.