Plant Interaction Among Poa Annua, Poa pratensis, and Lolium perenne Turfgrasses1
- A. D. Brede and
- J. M. Duich2
Annual bluegrass (Poa annua L.) Kentucky bluegrass (Poa pratensis L.), and perennial ryegrass (Lolium perenne L.) differ in their competitive abilities. To properly maintain stands of these species, turfgrass managers need specific information on how these grasses interact with one another and what conditions favor the growth of one species over another. The purpose of this study was to determine the effects and locations (above vs. below ground) of plant interaction among these turfgrasses under field conditions. Furthermore, information was sought on the effects of environmental variables on the competitive potential of these grasses. Plant interaction was studied by means of partitioned boxes, installed within a mature sod environment in the field. Species pairs were established in alternating chambers within the apparatus and were evaluated after 1 yr of growth. Below-ground partitions were used to confine the interaction to aboveground in one apparatus, and vice versa in another. Interspecific interaction was significant, both above and below ground, even though a relatively close mowing height (3.1 cm) and seemingly ample nutrients and water were supplied. All three species responded to interspecific interaction with reductions in root and shoot parameters. Competitive ability of perennial ryegrass was generally greatest below the ground, whereas Kentucky and annual bluegrass excelled above the ground. Tillering rate was used to assess the competitive potential of the three species under establishment conditions. Relative tillering rate, measured in the field via the growth of individual, transplanted shoots, generally increased with increasing temperature, daylength, and precipitation. Annual bluegrass had the highest rate of tillering of the three species during early autumn, whereas perennial ryegrass had the highest rate during early summer. Plant interaction among these species was characterized as the summation of their ability to proliferate tillers under establishment conditions and their ability to compete above and below ground under dense, solid-stand conditions.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .