Agronomy and Horticulture, Department of


Document Type


Date of this Version

November 1968


Published in Agronomy Journal VOL. 60, NOVEMBER-DECEMBER 1968. Copyright © 1968 American Society of Agronomy. Used by permission.


Two controlled environment experiments were designed to study the effect of photoperiod and a cold treatment on rhizome and tiller development of ‘Merion’ and ‘Windsor’ Kentucky bluegrass (Poa pratensis L.) Evidence is given to support the following conclusions:

1. A cold treatment is not essential for rhizome formation. Cold treatments increased tillering but reduced the number of rhizomes.
2. Both initiation and elongation of rhizomes were favored by a 16 or 18-hour photoperiod when compared to a 8- or 12- hour photoperiod.
3. Tillering showed little response to initial photoperiod, although more tillers were formed with a 12-hour than with an 8- or 18- hour photoperiod in one experiment.
4. Windosr generally produced more and longer primary and secondary rhizomes than Merion but the latter tillered more profusely than Windsor.