Effect of Temperatures and Water Table Depth on the Growth of Creeping Bentgrass Roots1

Abstract

AbstractThe PURR‐WICK system, as developed at Purdue University in 1966, provides an impermeable underlay, plus possible retention of free water by outflow drainage control. What would be the effect in this system of sand texture, depth of water reserve, and temperature? ‘Penncross’ bentgrass (Agrostis palustris Huds.) was grown in columns of finer and coarser sand mixes with water tables maintained at depths of 11, 25, and 40 cm in constant temperature chambers of 15 and 30 C for 9 weeks.Temperature had the greatest effect. At 15 C root growth was slow initially but steadily maintained. At 30 C initial root growth was rapid but declined to little or no growth, so that total root length at 15 C was three times that for 30 C. Within each temperature the water table ✕ sand interaction was significant. Root growth was better in the coarser sand for the 11‐ and 25‐cm water tables and better in the finer sand for the 40‐cm treatment. The deepest root growth was found at 15 C in the finer sand mix with the water table at 40 cm. Where oxygen diffusion was favored by coarse texture, roots were still limited by higher temperature.