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Abstract
Use of certain pesticides over a 3-year period caused a marked build-up of plant debris (thatch) of ‘Kentucky’ bluegrass (Poa pratensis L.) turf above the soil surface. Applications of the chlorinated hydrocarbon insecticides, dieldrin and chlordane, resulted in a thatch layer of 20 mm or more. The use of the carbamate insecticide, carbaryl, caused an average match thickness of 1.3 mm. The plots that received no insecticides or the mercuric fungicide, phenyl mercuric acetate (PMA), had no measurable thatch. The match depths were closely associated with plant debris wt.
As the no. of earthworm burrows increased, the amount of thatch decreased. Where earthworms were present to any extent, thatch was virtually non-existent.
Abstract
Physical properties of various hardwood bark-soil mixes for containers were compared to a soil-peat-perlite mix. Bark-soil mixes containing a wide range of bark particle sizes were found to possess superior physical properties initially and remained satisfactory after a 13-month incubation period. However, bark-soil mixes were much less stable and deteriorated to a significantly greater extent. For golf greens, physical properties of hardwood bark or peat and soil and sand mixes were studied following compaction at 40 cm moisture tension. Initially, the bark mixes were superior and this was postulated to be due to a more uniform distribution of bark within the mixes. Based on the deterioration that occurred in bark-soil mixes for containers, it is concluded that use of hardwood bark in golf green mixes does not appear feasible.
Abstract
Hardwood bark was used in combination with other materials as media for forsythia and juniper plants in containers with various growing procedures, bark sources, and fertility practices. Based on dry wt, the most rapid growth of forsythia was obtained in a bark and fine sand medium; whereas, the least growth was obtained in soil, peat, and perlite. However, pfitzer juniper plants under 2 different fertility regimes grew most rapidly in a bark, soil, and peat medium, slowest in a bark and torpedo #2 sand medium, and at an intermediate growth rate in soil, peat, and perlite. The standard mix (soil, peat, and perlite) was more acidic than the experimental mixes containing bark and sand. Chlorotic plants were more numerous in acidic mixes. Leaf tissue analyses from the plants grown in the peat amended bark and standard mix had higher Fe and Mn concn than plants grown in a bark-sand mix.