Date of Pollen Shedding by Longleaf Pine Advanced by Increased Temperatures at Strobili

Abstract

Air temperatures in the microenvironments of flower buds of Pinus palustris Mill. appear to be a major determinant of flowering date. Shoots bearing staminate strobili on each of 10 trees were bagged at different times and for varying lengths of time in January and February. Bagging treatments provided 488 to 3,852 additional degree-hr of heat above 50°F accumulated from January 1. Flowering date was advanced more or less in proportion to added heat, up to an average of 8.6 days ahead of unbagged controls. Individual trees varied widely in date of pollen shedding.

Citation

Boyer, W.D.; Woods, F.W. 1973. Date of Pollen Shedding by Longleaf Pine Advanced by Increased Temperatures at Strobili. Forest Sci. 19:315-318