Late Fall Potassium Application and Timing of Turf Cover for Kentucky Bluegrass Spring Green-up

Sang-Kook Lee1,*   

1Department of Biotechnology, Hoseo University, Asan 31455, Korea


Kentucky bluegrass (Poa pratensis), one of the cool-season grasses, has inappropriate growth when air temperature is lower than optimum range which are 18 to 24℃. It leads to sluggish growth, weed invasion, disease outbreak, and drought stress. Potassium (K) which is an essential nutrient for turfgrass growth is well-known to enhance turfgrass ability to tolerate environmental stresses such as low temperature stress. Turf cover has been used to protect the crowns from direct low temperatures and desiccation during the winter season. However, limited information has been reported on timing of the turf cover application and interaction with potassium application to improve cold tolerance. The objective of the study was to investigate the timing of turf cover application and late fall potassium application for Kentucky bluegrass spring green-up. The six timing of turf cover application which are no cover, daily, December, January, February, and March were treated. The four K rates which are 0, 5, 10, and 20 g m-2 were applied. The K application did not have effects on Kentucky bluegrass spring green-up. When air temperature is lower than 18℃, the effects of turf cover application is required for the period of 33 days for spring green up. If the period for cover application is less than 11 days, no effects of turf cover were found for turfgrass quality and coverage. When relatively high turf quality is required in the season of spring green up, the turf cover would be applied at the December, January, or February to ensure the enough period of turf cover application for increase spring green up.

Figures & Tables

Fig. 1. Maximum, minimum and average air temperature (℃) from March 16, 2017 to June 18, 2017. Relative humidity (%) was measured at the same measurement day as temperature measurement.