A comparison of the performance and growth of a range of turfgrass species under shade

The increased use of semi and fully enclosed sports stadiums necessitates the ongoing selection, development and assessment of shade-tolerance in turfgrass species. Vertical shoot growth rate is a simple biological measure that may supplement visual turfgrass assessment and provide a useful measure of shade adaptation. Cool-season temperate turfgrasses; Kentucky bluegrass-perennial ryegrass (Poa pratensis L.-Lolium perenne L.), creeping bentgrass (Agrostis palustris Huds.), supina bluegrass (Poa supina Schrad.) and tall fescue (Festuca arundinacea Schreb.), and a warm season species, Bermudagrass (Cynodon dactylon L.), were established in pot and field experiments and subjected to 4 shade treatments (0, 26, 56 or 65% shade) under ambient conditions. Average light readings taken near the winter and summer solstice in full sunlight at midday, were 790 and 1980 μmol/m2.s, respectively. Field and pot trials confirmed supina bluegrass and tall fescue to have the greatest shade tolerance, producing high turf quality under 56 and 65% shade. However, all turfgrass species declined in quality under high shade levels as indicated by an increase in thin, succulent vertical growth, and a less-dense turf sward. Vertical shoot growth rates of all species increased linearly with increasing shade levels. Kentucky bluegrass-perennial ryegrass had the highest rate of increase in vertical shoot elongation under shade, approximately 3.5 times greater than supina bluegrass, which had the lowest. Low rates of increase in vertical shoot elongation under shade indicated shade tolerance whereas high rates inferred shade intolerance.