ARS | Publication request: Chilling Requirement Studies in Blueberries

Submitted to: Small Fruit Reviews
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 2002
Publication Date: July 27, 2004
Citation: Spiers, J.M., Marshall, D.A., Braswell, J.H. 2004. Chilling Requirement Studies in Blueberries. Small Fruit Reviews. 3:(3)325-330.

Technical Abstract: Separate studies were initiated in January, 1998 on rabbiteye ( V. ashei) and southern highbush (V. corymbosum L.) blueberry plants that had received > 500 chilling hours (<7°C). In both studies, plants and terminal stems with at least 2 flower buds from matching plants were forced in a greenhouse with a temperature range of 17°C - 23°C and natural daylength. The terminal two flower buds from both cuttings and paired stems on intact plants were rated for floral bud development. In 'Magnolia,' cut stems with leaves removed did not differ significantly in flower bud development from intact container plants forced under the same environmental conditions. Floral buds on cuttings with intact leaves showed significantly slower development than cuttings with no leaves or with intact plants. With 'Tifblue,' stems with a 5 mm basal section removed weekly to retard vascular blockage did not differ in floral bud development from stems without basal pruning. Cut stems did not differ from matching intact stems for the first 3.5 weeks of forcing. At this time 'Tifblue' flower buds had reached 3.7 on floral development scale. After 4.5 weeks of forcing in the greenhouse floral bud development ratings on cut stems were significantly lower than those on intact stems. These studies indicate that floral bud development in cut stems approximate that of intact plants for a period of 4 weeks.