Isolated Plot Technique for Studying Seedling Growth of Turfgrasses 1

Field research with turfgrass seedlings is frequently complicated by weather disruptions and sampling error. A technique was developed for affixing turf seeds to a seedbed in the field for the purpose of monitoring field survival and growth of seedlings over time. Isolated plots of turfgrass seeds, 25 mm in diam and spaced 75 mm apart on a seedbed, were held in place with a liquid latex‐based mulch and a non‐woven fabric mulch. Seed displacement from rainwashing was held below 0.1% with this technique. The latex/fabric mulches had the same effect on seedling growth as do conventional mulches of straw or wood fiber; therefore, use of the latex/fabric mulches in this technique did not seem to constitute a serious deviation from standard planting practices. Results from field evaluations revealed that field survival (percent germination) was accurately assessed using this technique without the added variance associated with subsampling of solid stands. Field survival of perennial ryegrass ( Lolium perenne L.) seedlings sown at 59 200 seeds m −2 could be measured with 9% variability (CV), vs. 35 to 51% variability with traditional sampling‐probe methods. Values of field survival obtained using isolated plots corresponded closely with values found in solid stands but with lesser variability. Plant growth parameters (leaves, shoots, roots) in isolated plots and solid stands diverged over time; interspecific competition occurred sooner in solid stands than in isolated plots. Care should be taken when extrapolating seedling growth results found using this technique to solid stand conditions since the seedlings are essentially space planted.