Heat tolerance in garden roses Academic Article uri icon


  • 2019 International Society for Horticultural Science. All Rights Reserved. Roses generally experience a decrease in flower productivity and size in response to summer temperatures greater than 30C that is common throughout the southern states of the USA. In College Station, Texas, the August mean and mean maximum summer temperatures can be 32 and 40C, respectively. Under these extreme heat stress conditions, a large rose germplasm collection was evaluated for flowering intensity that takes into account both flower number and flower size. Of the 234 accessions evaluated, most showed moderate flowering during August and about 6% consistently had over 50% flower intensity in August. Experiments done in the growth chamber with potted roses containing young flower buds indicated that a 3-h heat shock (44C) treatment resulted in decreased flower size and increased flower abscission. Consequently, this approach was used to assess the heat tolerance of 18 rose cultivars in this collection. The results indicated that field ratings of heat tolerance based on flower productivity were negatively correlated to flower abscission and leaf necrosis (r=-0.55* and r=-0.64**) and not correlated with leaf MTS (cell membrane thermostability) of the potted rose plants subjected to the heat shock treatment.

published proceedings


author list (cited authors)

  • Greyvenstein, O., Pemberton, H. B., Niu, G., Starman, T., & Byrne, D. H.

citation count

  • 0

complete list of authors

  • Greyvenstein, O||Pemberton, HB||Niu, G||Starman, T||Byrne, DH

publication date

  • February 2019