Inter- and Intra-Specific Variation in Wear Mechanisms in Agrostis: I. Wear Tolerance and Recovery II. Anatomical, Morphological and Physiological Characteristics
Creeping bentgrass (Agrostis stolonifera L.) and velvet bentgrass (Agrostis canina L.) are the principal grass species for golf course putting greens in northern latitudes. Wear injury is a major physical stress that limits the function and quality of turfgrass. Wear evaluations in Agrostis species are limited and no studies have been conducted to evaluate recovery from wear and associated wear mechanisms. To that end, Agrostis species and genotypes were evaluated for wear tolerance and recovery on a golf green built according to USGA specifications. Equal numbers of creeping bentgrass and velvet bentgrass genotypes were tested. Wear was applied using a grooming brush over a 3-year period and plots were visually rated for wear and recovery. As much as 90% of the total variation in Agrostis wear tolerance was due to interspecific variation. Velvet entries provided significantly better wear tolerance than creeping bentgrass. Velvet bentgrass genotypes provided acceptable wear tolerance and full recovery in most years with the exception of SR-7200. None of the creeping bentgrass entries evaluated exhibited acceptable wear tolerance or achieved full recovery. Fourteen Agrostis genotypes, which included equal numbers of creeping and velvet species were selected for further evaluation of anatomical, morphological and physiological characterstics associated with wear tolerance. Eleven characteristics were measured comparing greenhouse grown spaced-plants established from field plots and seed. Characteristics included tiller density, shoot dry weight, shoot water content, relative water content (RWC), leaf width, leaf strength, leaf angle, crown type and leaf cell wall constituents. Siginificant interspecific difference in charactersitics were found. Little difference at the intraspecific level was obserevd especially within creeping bentgrass. Wear tolerant velvet genotypes were associated with a more vertical tiller and leaf angle, greater cell wall content and greater shoot density. Lignocellulose content accounted for as much as 62.8 to 72.3% of the variation in Agrostis wear tolerance while tiller density accounted for as much as 65.9 to 75.8%. Wear tolerance in Agrostis can be improved by giving priority to breeding for greater density and cell wall content with secondary emphasis to breeding for a more upright growth habit (tiller and leaf).
School:University of Massachusetts Amherst
School Location:USA - Massachusetts
Source Type:Master's Thesis
Keywords:wear tolerance velvet bentgrass creeping recovery agrostis golf course putting green agronomy
Date of Publication:01/01/2008