Optimizing Laccase Application on Creeping Bentgrass (Agrostis stolonifera L.) to Facilitate Biodethatching

Abstract

ABSTRACTOrganic matter buildup in the form of thatch or mat layers leads to several problems in turfgrass management systems. In a previous greenhouse study, laccase enzyme solution reduced the rate of accumulation of organic matter when applied at an activity level of 2.0 units cm−2 every 2 wk for 9 mo on ‘Crenshaw’ creeping bentgrass (Agrostis stolonifera L.). A 2‐yr field experiment was conducted on creeping bentgrass to optimize the laccase activity level, frequency of application, and to determine potential interactions with core aeration and topdressing cultural practices. Laccase enzyme at five activity levels, 0, 0.5, 1.0, 2.0, and 4.0 units cm−2, was applied every 2 wk. The frequency of laccase application was tested using a laccase activity level of 2.0 units cm−2 applied at frequencies of 2, 4, 8, or 12 wk. The common cultural management practices of core aeration and sand topdressing were compared with and without laccase enzyme at an activity level of 2.0 units cm−2 applied once a month. Results indicated that laccase treatments were effective in reducing thatch layer thickness (TLT) at rates as low as 0.5 units cm−2 applied every 2 wk and as infrequent as once a month when applied at a rate of 2.0 units cm−2. Laccase application at 2.0 units cm−2 once in 4 wk was just as effective at reducing TLT as was core aeration and sand topdressing twice per year. Even greater reductions in TLT were observed when laccase was applied in combination with core aeration and sand topdressing.