Effects of High Temperature and Poor Soil Aeration on Root Growth and Viability of Creeping Bentgrass

Abstract

Turf quality declines in creeping bentgrass (Agrostis palustris Huds.) with increasing temperatures and decreasing soil aeration. This experiment examined how root activities of ‘Crenshaw’ and ‘Penncross’ were affected by high temperature and low soil aeration. Turfgrass was maintained in growth chambers at day/night temperatures of 22/15°C (optimum) or 35/25°C (high temperature, HT). Aeration treatments were: (i) adequate aeration by maintaining soil medium well‐drained; (ii) low aeration (LA) induced by maintaining soil medium saturated with water. Shoot dry matter production (SDM) declined with HT + LA at 7 days of treatment (DOT) in Penncross, and at 21 and 35 DOT with HT, LA, and HT + LA for both cultivars. Reduced root dry mass was measured at 7 DOT under HT + LA, and at 21 and 35 DOT under HT, LA, or HT + LA for both cultivars. Root viability was lower after 7 DOT and 21 DOT of HT, LA, and HT + LA. Viability was reduced more in Penncross than in Crenshaw after 21 DOT with HT + LA, and 35 DOT with HT and HT + LA. Root porosity increased with LA and HT + LA, beginning 7 DOT for both cultivars, to a greater extent in Crenshaw after 21 and 35 DOT with HT + LA. The combination of HT and LA had more severe effects on viability than either HT or LA alone. Results suggest that reductioin root growth, and particularly root viability, under HT and LA could contribute to the declines and cultivar variations in bentgrass quality.