Seeds which remain hard at the end of the prescribed test because they have not absorbed water, due to an impermeable seed coat, are to be counted as ``hard seed.'' If at the end of the germination period provided for legumes, okra, cotton and dichondra in these rules and regulations there are still present swollen seeds or seeds of these kinds which have just started to germinate, all seeds or seedlings except the above-stated shall be removed and the test continued for 5 additional days and the normal seedlings included in the percentage of germination. For flatpea, continue the swollen seed in test for 14 days when germinating at 15-25 C or for 10 days when germinating at 20 C. [5 FR 33, Jan. 4, 1940, as amended at 10 FR 9952, Aug. 11, 1945; 20 FR 7936, Oct. 21, 1955; 65 FR 1708, Jan. 11, 2000] Sec. 201.57a Dormant seeds.
Dormant seeds are viable seeds, other than hard seeds, which fail to germinate when provided the specified germination conditions for the kind of seed in question.
(a) Viability of ungerminated seeds shall be determined by any of the following methods or combinations of methods: a cutting test, tetrazolium test, scarification, or application of germination promoting chemicals.
(b) The percentage of dormant seed, if present, shall be determined in addition to the percentage of germination for the following kinds: Bahiagrass, basin wildrye, big bluestem, little bluestem, sand bluestem, yellow bluestem, bottlebrush-squirreltail, buffalograss, buffelgrass, galletagrass, forage kochia, blue grama, side-oats grama, Indian ricegrass, johnsongrass, sand lovegrass, weeping lovegrass, mountain rye, sand dropseed, smilo, switchgrass, veldtgrass, western wheatgrass, and yellow indiangrass.
(c) For green needlegrass, if the test result of method 2 is less than the result of method 1, subtract the result of method 2 from method 1 and report the difference as the percentage of dormant seed. Refer to Sec. 201.58(b)(7). [46 FR 53638, Oct. 29, 1981, as amended at 59 FR 64506, Dec. 14. 1994]