Structure of a black plug layer in a turfgrass putting sand green

ABSTRACT:

The use of high-sand-content turfgrass putting greens in the last two decades has been associated with the increase in prevalence of microbiologically generated black plug layering. A transect horizontal section analysis of a die-back zone in a green at the Tor Hill Golf Course of the City of Regina, Saskatchewan, revealed a complex structural entity forming this layering. It was comprised of columnar processes, lateral plates, and globular masses. Much of the biomass occurred within a zone 4 to 16 mm (0.16–0.63 inch) below the surface, and a large surface area to volume ratio was evident from the convoluted nature of the surface of the black plug layer. Where grass roots penetrated through the layer, there was usually more than 3 mm (0.12 inch) of uninfested sand around the root.