96 GRA.SSES OF IOWA. 



to an interruption in the plan of the expsriipents, but the results 

 made were interesting and instructive. The results of the work 

 ind cated that seeds which were soaked for a considerable period 

 of time and then allowed to dry, failed to show as good germi- 

 nating plants as those not soaked. The per cent of germina- 

 tion being in some cases lower and on the whole the germina- 

 tion proceeding more rapidly when the seeds had been moist- 

 ened. The germinated plants from seeds moistened for a con- 

 siderable period were easily subject to the attacks of sapro- 

 phytic fungi, and heoce made a very feeble growth. 



Rambousek* states tl at experiments with rye, wheat and 

 barley have sho jvn that such seeds in which the radicle only 

 is injured may continue to germinate, and that in this respect 

 wheat and rye are much more resistant than barley. 



THE PURITY AND VITALITY OF GRASS SEED. 



CARLETON R. BALL. 



In the following pages have been brought together most of 

 the available facts pertaining to this subject which seem 

 important in determining the status of our grass seeds 

 with reference to their purity and vitality. Reference has 

 been made to only such works as gave the results of a consider- 

 able number of tests and the subject is further confined to our 

 own country. For four of our common species the results 

 obtained from miscellaneous sources have been summarized by 

 the author under the heading "various other tests, " acd all the 

 data are presented in tabular form for better comparison. 



A study of the tables will show beyond doubt that the 

 quality of commercial grass seed has improved considerably in 

 the last fifteen years. It will also show as conclusively that 

 further improvement is not only necessary in the interest of 

 good pastures and clean farms, but is also easily possible. 

 Tables Nos. V, VI and VII give both purity and vitality of a 

 large number of species of grasses. 



PURITY. 



Since the '60 's, when Nobbe made his classic disclosures of 

 the deplorable state of affairs which then existed in Europe, 



♦Pruger. landw. Wochenblatt. 1895:393. Centr. Agrlkulturch. 24: 393. 



