Tillering and Persistency in Perennial Ryegrass1
- J. W. Minderhoud
Two field trials were performed to investigate the regeneration of divergent perennial ryegrass (Lolium perenne L.) cultivars in monostands under various treatments. The first trial investigated the effects of simulated traffic and N fertilization on the number of vegetative shoots during the season. It revealed that perennial ryegrass, though considered to be a ‘tread-species’, does not need traffic to thrive. Nitrogen fertilization increased shoot density with close, frequent cutting.
It was found that perennial ryegrass produced vegetative shoots with extended internodes. Therefore, a second experiment studied the incidence of these abnormal tiller types. In addition to the normal, unelongated shoots, two types of abnormal shoots were found in perennial ryegrass: (i) subsidiary shoots on the raised nodes of flowering stems; (ii) partly elongated vegetative shoots. Both types occurred in all the cultivars examined, but not to the same extent. The percentage of shoots of the first type varied little among the different cultivars, but the percentage of elongated shoots of the second type varied greatly in proportion to shoot density. Cultural practices common on sports fields did not seem to influence the incidence of abnormal vegetative shoots.
Raised or elongated shoots in a horizontal position (pseudostolons) enable the plant to spread at rates of 1 to 5 em per year, at least twice the rate resulting from gradual apex displacement by unelongated internodes. Nevertheless, it may be undesirable to develop new cultivars with even more internode elongation because present-day cultivars already produce many elongated shoots, and cultivars with even more would be rather frost-susceptible and thus persistency would be threatened.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 1980. . Copyright © 1980 by the American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, and International Turfgrass Society, 5585 Guilford Rd., Madison, WI 53711 USA