The effects of temperature, photosynthetic photon flux density (PPFD) and photoperiod on vegetative growth and flowering of the raspberry (Rubus idaeus L.) `Autumn Bliss' were investigated. Increased temperature resulted in an increased rate of vegetative growth and a greater rate of progress to flowering. Optimum temperatures lay in the low to mid 20°C range. Above this the rate of plant development declined. Increased PPFD also advanced flowering. While photoperiod did not significantly affect the rate of vegetative growth, flowering occurred earliest at intermediate photoperiods and was delayed by extreme photoperiods. These responses suggest that there is potential for adjusting cropping times of raspberry grown under protection by manipulating the environment, especially temperature.
J.G. Carew, K. Mahmood, J. Darby, P. Hadley, and N.H. Battey
J. Raymond Kessler Jr., Jeff L. Sibley, Bridget K. Behe, Darby M. Quinn, and James S. Bannon
Fifty-seven herbaceous perennials were evaluated from July 1996 to October 1997 in USDA Hardiness Zone 8. Plants in this study generally performed better the first year after planting than the second year. Several selections did not reemerge the second year, though some natural reseeding occurred. Still other selections never fully recovered from the winter months or succumbed to stress in the summer. Plants that maintained an attractive foliage display while not in bloom and plants that had a high bloom rating during the bloom season are worth incorporating into a full sun perennial or mixed border in the southeastern United States. Performance of perennials in the landscape may vary from year to year as climatic conditions affect performance. Comparison of results from variety trials at other locations should help increase performance information reliability for perennial selection.