Cone characteristics and seed quality 10 years after an uneven-aged regeneration cut in shortleaf pine stands (2002)Grayson, K. J., Wittwer, R. F., & Shelton, M. G. (2002). Cone characteristics and seed quality 10 years after an uneven-aged regeneration cut in shortleaf pine stands. Southern Research Station, General Technical Report SRS-48. Retrieved from http://www.srs.fs.usda.gov/pubs/viewpub.php?index=3140 Cone characteristics and seed quality for 16 released (stand density 14 square meters per hectare) and 16 unreleased (stand density 28 square meters per hectare) shortleaf pine (Pinus echinata Mill.) trees were described by d.b.h. class (28, 33, 38, 43 centimeters) and crown position (upper south, upper north, lower south, and lower north). The 38-centimeter d.b.h. class produced significantly heavier cones than other classes. Average cone dry weight for released trees did not differ significantly by crown position, but the lower north crown position produced significantly lighter cones for unreleased trees. Total seeds per cone did not differ significantly between released and unreleased trees, by d.b.h. class, or crown position; the overall average was 46 seeds per cone. Upper crown positions produced a higher percentage of sound seeds per cone (61 percent) than the lower crown positions (50 percent) for both released and unreleased trees. The percentage of sound seeds also differed significantly between released and unreleased trees with the 38- and 43-centimeter d.b.h. classes of released trees producing the highest percentage. Both released and unreleased trees produced significantly more sound seeds per cone in the upper south crown position (31 seeds per cone) compared to the other crown positions (averaging 25 seeds per cone). Seeds from released trees averaged 91 percent germination compared to 85 percent for unreleased trees http://www.srs.fs.usda.gov/pubs/viewpub.php?index=3140
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