Q & A WITH PAMELA SHERRATT

I am currently a bit concerned that we will not be able to accomplish our fall overseeding work this year by October 1 due to the ongoing labor issue and now potential damage from fall armyworms . Would you have any guidance or recommendations for repairing these damaged areas , including dormant seeding ?

The great fall armyworm invasion of 2021 is something for the books , and not something anyone expected . Fall armyworms ( FAW ) are tropical pests that got carried up to the north on summer storm systems . The adult moths dropped from the skies and laid eggs , which hatched into larvae ( caterpillars ), which then heartily munched their way through turfgrass leaf tissue on golf courses , sports fields and lawns . The damage was quick , widespread and unexpected . Some turf areas that were treated with insecticides such as Acelepryn in the spring or early summer seem to have avoided damage . Conversely , grasses that we thought might be immune to attack , like turf type tall fescue containing endophytes , were eaten . This will lead to discussions about endophytic grasses and how age of seed and storage methods might affect levels of alkaloids in the turf plant . As I ’ m writing this , BugDoc ( Dr . Dave Shetlar ) told me that the FAW larvae have now pupated , with new adults emerging and laying eggs . The cycle from egg to feeding larva is only about 30 days , so we must remain vigilant for round two of FAW damage this fall . Leading up to the first frosts in October , it would be wise to keep an eye on new grass areas to scout for any larval damage , and to possibly apply a low rate of Acelepryn or Tetrino as a curative and future preventive control . If larvae are seen , a liquid application on a pyrethroid product would offer a quick knockdown . Granular products are effective , but need rain or irrigation for activation .

To help the damaged turf recover , protect the turf plant crowns by limiting any kind of mechanical injury ( mowing , scarifying , coring etc .) and keeping the crowns hydrated . Avoid the temptation to apply too much fertilizer to turf at this time , as there is research to suggest that the female moths detect areas of lush , fertile turf and lay their eggs accordingly . If damaged turf got very dry and it looks like the crowns will not sufficiently recover , overseeding or slit-seeding may be necessary . October 1 is a sound cut-off date for seeding to make sure new seedlings are established well before the first frosts , but look at the long-range forecast and maybe push that window a little . Quick-germinating species such as perennial or tetraploid ryegrasses will provide quicker ground cover than turf-type tall fescue , and much quicker ground cover than Kentucky bluegrass . However , it appears that FAW is not feeding on Kentucky bluegrass turf , so plan on using bluegrass seed in damaged areas . If it ’ s too late to do that now , apply it as a dormant seed . If possible , use growth blankets to retain moisture and heat , and to keep people off renovated areas . A growth blanket is one tool that can help save labor , since turf under the blanket needs less frequent watering and other care . Once the window for seed germination has passed , usually around mid to late October , plan to continue renovation efforts in late winter . In February-March 2022 , if there is no snow cover , and if weather allows , apply dormant seed to bare / thin spots , using walk-behind equipment that won ’ t cause soil disruption and compaction . During the freezing and thawing cycles in late winter , the soil structure changes due to the swelling and shrinkage of soil particles , the volume of frost-susceptible soils increases , and pores expand due to ice expansion during freezing . These soil pores offer a great opportunity for seed : soil contact . Once the soil temperatures get consistently about 50 degrees Fahrenheit , the seed is in place to germinate . Dormant seeding offers a kick-start to the season , but seed rates should be slightly higher to compensate for any seed loss . Dormant seeding during the “ off ” season might also offer a benefit to turf managers who are struggling with labor during the busy season . Since infestations of FAW are typically on a 3 to 7-year cycle , it is hoped that we do not have to deal with this again in 2022 . However , if the last two years have taught us anything , be prepared for all possibilities ! SFM

Pamela Sherratt Sports turf extension specialist The Ohio State University

Questions ? Send them to Pamela Sherratt at 202D Kottman Hall , 2001 Coffey Road , Columbus , OH 43210 or sherratt . 1 @ osu . edu

Or , send your question to Dr . Grady Miller , North Carolina State University , Box 7620 , Raleigh , NC 27695-7620 , or grady _ miller @ ncsu . edu

50 SportsField Management | October 2021 sportsfieldmanagementonline . com