To determine the effect that different traffic schedules have on Kentucky bluegrass performance. Specifically we were interested in determining if the same amount of traffic caused more injury if it was applied all-at-once (one day per week) or spread out over time (a little each day).

The study was conducted at the Horticulture Research Farm in Ames Iowa during summer and fall of 2001. Six different traffic regimes were applied to Kentucky Bluegrass (Table 1) with a GA-SWC Traffic simulator (Carrow et al., 2001). The experimental design was a randomized complete block with 7 treatments and 3 replications. Each small plot was 2 ft x 12 ft. Traffic simulation started on 1 August and ended on 7 November, 2001.

Table 1. Traffic schedule followed on Kentucky bluegrass during fall 2001.

Percent turf cover and quality were evaluated monthly. Sometimes conditions were too wet to operate the traffic simulator. Traffic not done during those days accumulated to the next available day.

Table 2. Kentucky bluegrass cover as affected by traffic schedule

Table 3. Kentucky bluegrass quality as affected by traffic schedule

Turf cover decreased as the amount of traffic increased. At 10 and 15 passes per week more turf cover occurred with concentrated traffic compared to disperse traffic (table 2). Similar situation occurs on turf quality (table 3). Although this is not evident in the data, there may have been a complicating factor caused by the unpredictable rainfall events. Traffic treatments applied during wetter conditions may have caused more damage. In 2001 we will conduct the same levels of traffic under wet vs. dry conditions by controlling rainfall with tarps.