Tillering, Internode Development, and Dry Matter Partitioning in Creeping Bentgrass

Abstract

High tiller density and stolon development are critical to wear tolerance and persistence of creeping bentgrass (Agrostis palustris Huds. synonym A. stolonifera L.). A better understanding of creeping bentgrass growth and development would be helpful in screening germplasm for improved turf characteristics. The objectives of this study were to determine tiller appearance and main stem elongation and development, and to determine above ground dry matter partitioning, in high and low tillering populations of creeping bentgrass grown under low light (150 μmol m−2 s−1). Individual, pregerminated seeds of cv. Emerald and germplasm UM67‐10 were transplanted into 10‐cm pots containing an 80:20 (v/v) sand:peat media. Two growth cabinet experiments were conducted under 16‐ and 8‐h photoperiod and 20/15°C day/night temperatures. Phenological development was monitored through 35 d after transplanting (DAT). Dry weight per tiller was correlated to tiller age for main stem and primary tillers (r = 0.98 and r = 0.99) and secondary tillers (r = 0.93 and r = 0.99) for UM67‐10 and Emerald, respectively, at 35 DAT. Dry weight per tiller was related to tiller elongation. Population differences for dry weight accumulationper day were significant (P = 0.05) for lower order tillers. The germplasm UM67‐10 initiated tillering earlier and main stem elongation later than Emerald. Tillers per plant were correlated to tiller appearance date. Elongating tiller weight within populations was related to main stem elongation date and its final length. Late season planting, when daylight is decreasing, will result in a bentgrass stand with fewer tillers per plant and with little elongated stem growth. Screening germplasm for tiller production in a growth cabinet may facilitate identifying grasses with high tiller density and improved wear tolerance.