Required mowing events of transgenic Kentucky bluegrass cultivars compared with conventional turfgrass cultivar blends and species mixtures

Mowing is a labor-intensive yet important cultural practice to maximize turfgrass health and performance. Selecting cultivars with a slower vertical growth habit can help reduce mowing frequency and improve turfgrass quality (TQ). New transgenic Kentucky bluegrass (Poa pratensis L.) (KBG) cultivars with a dwarf growth habit have been developed by overexpressing the gibberellin 2-oxidase pathway. However, the impact of this overexpression on the number of required mowing events and mowing frequency in the field is unknown. Therefore, the primary objective of this research was to quantify the required number of mowing events based on the one-third rule of four transgenic cultivars (‘ProVista’) (PV) and 16 conventional turfgrass cultivars, blends, and mixtures. Over the 2-yr research period, four PV cultivars in the top statistical group averaged ≤21 mowing events, whereas all other turfgrasses averaged ≥41 mowing events. For mowing frequency, all PV cultivars required an average mowing frequency of ≥20 d, whereas all other turfgrasses required an average mowing frequency of ≤10 d. Although the PV cultivars required half as many mowing events, two of the PV cultivars were consistently in the top statistical group for TQ. The PV KBG cultivars represent new technology for turfgrass genetics with the novel trait of reduced mowing that can benefit the industry by reducing mower emissions, noise, and use, as well as increased TQ and flexibility for turfgrass practitioners, since mowing frequency can be extended.