18 



PROPAGATION OF PLANTS BY MEANS OP SEEDS 



old seeds are sometimes polished or bleached or are mixed with 

 fresh seeds. 



Testing Seeds. — Probably the best way of detecting the value 

 of seeds is to test their power of germination. If ninety or more 

 out of a hundred will germinate well they may be used for planting. 

 This would indicate maturity, good storage, freshness. 



Simple Testers. — It is usually not necessary to purchase any 

 apparatus for seed testing, either at home or at school. A rag-doll 

 tester, made of a piece of cloth, is one of the most satisfactory. 



(Fig. ID- 



Mark the cloth with a soft lead pencil into areas about three or 



Fia. 11. — Rag doll method of testing seed corn. Each roll of cloth contains the sample 

 kernels from about twenty or thirty ears. The open cloth shows the variations in germi- 

 nation. (Photo from Iowa Experiment Station.) 



four inches square. On each square mark a number and place a 

 sample of the seeds to be tested. Use 25 each for large seed's, and 

 100 each for small seeds. Fold in the sides of the cloth. Then roll 

 it up on a small stick the size of a pencil, and tie the roll. Slip out 

 the stick to admit plenty of air. Soak it for an hour or two. Then 

 allow the surplus water- to drain off and keep it covered to hold the 

 moisture, for a week or so. Examine by unrolling so carefully as to 

 not displace the seeds from their own squares. Count how many 

 sprout well and determine the percentage. 



Testing may be done by keeping the seeds moist on blotters 

 between plates or pie-pans. They may also be sprouted in boxes 

 of moist sand or soil. 



