How much traffic can my fields take in the early season?
“Cabin fever” that creates an insatiable desire to get out and run around is an annual rite of Spring. However, early season traffic on sports fields and golf courses present a number of critical challenges. First, the soil is often close to saturation as the snow melts and frost comes out of the ground. This puts most typical soils in an ideal condition to CREATE COMPACTION. Soil particles are lubricated and able to be forced closer to other soil particles, especially if there are any fine particles (silt and clay) in the profile. Sand-based systems do alleviate this issue, however surface organic matter often accumulates and can create moist and soft conditions if not properly managed through topdressing. The second aspect of early season traffic is growth rate. A quick look at the Turfgrass Growth Potential (a measure based on temperature on the percentage of ideal growth expected) indicates most turf is at 20% of ideal growth at this time. If we are putting significant traffic over turf that is only at 20% of ideal growth, you can expect severe thinning. Thinning leads to bare soil, weeds and unsafe sports turf. In a sports turf situation consider a significant repetitive overseeding of a rapidly germinating species such as perennial ryegrass or tall fescue. Golf turf managers face similar dilemma with annual bluegrass/creeping bent grass putting surfaces. Too much early play on less than actively growing turf, can lead to thinning and algae. Creeping bentgrass dominated surfaces will not be able to compete with annual bluegrass under Spring and Fall traffic periods and often lead to increases in annual bluegrass populations.
Should I apply seedhead suppression to injured turf?
This is a tough question alluded to last week (Vol.16:1) with plusses and minuses. A damage assessment must be conducted. If there is widespread turf loss with little annual bluegrass surviving, then there is little point to seed head suppression. If there are only minor areas (low spots, dry knobs, etc.) and the majority of annual bluegrass survived then I would recommend seed head suppression. It is the in-between assessments that present a challenge. There is little evidence that PGR’s significantly alter seed germination and establishment of new seedlings.
The turf that was not killed but injured will be slowed in its recovery but if you feel it will recover than seed head suppression should be applied. It may slow recovery however the benefits of seed head suppression for annual bluegrass performance during the season is well known. Based on the Rutgers BMPs for anthracnose, redirecting energy from seed development into other plant energy needs helps.