Stratification of shortleaf pine seeds
Tests with 16 separa te lo 1s of shorr leaf pine (Pinus echinata Mill.) seeds, represen ting various sources and years of coll ection, indicate th a t the greatest increase in speed of germ ina ti on occurred a ft er stra tifica tion for 56 to 70 days. Stratification increased total germinat ion over th at of the contro l, but th ere were no d ifferences between treatments tor periods of from 14 to 84 days. Since sho rtleaf pine (Pinus echinata Mi ll. ) seeds are usua lly dormant, cold stra tifica tion for 30 to 60 days has heen recommended for prompt, complete germination (2, 7, 8). T hese recommenda tions were based on completeness rather than speed o f ge1mina tion . Seidel (6), on the other hand, working with a single seed lo t, found that germina tion speed increased progres, ively with lengths of s tra tifica tion up to 60 days. This paper reports speed and completeness of germination af1 er stratifying seeds of vary ing ages for periods from I 4 to 84 clays.