December, 1922] results of seed tests, 1922 3 



ning at the lower temperature for eighteeen hours and 

 at the higher temperature for six hours each day. 

 Most seeds require rather definite and constant tem- 

 peratures, accompanied by certain prescribed moisture 

 conditions. Should any one of these conditions be 

 temporarily out of adjustment, it may result in the loss 

 of a whole set of tests. With extremely long tests, 

 ventilation and sterilization must be most carefully 

 regulated to prevent molds from vitiating the results. 



A large proportion of our agricultural seeds can 

 be tested in about five days. The sprouts are counted 

 at the end of three days for a preliminary reading and 

 finally at the end of five days as a figure for the total 

 viability. Duplicate tests must be run, however, and 

 if the two tests vary to any appreciable extent the seed 

 must be run again to get more results for averaging. 

 If the test is repeated, it means at least ten days and 

 more often fourteen before the proper result can be 

 obtained. This, with the time of sending the seeds 

 and the reports through the mail, means the con- 

 sumption of at least two weeks' time. Add to this the 

 disadvantage of having a large proportion of the seeds 

 coming in during four or five weeks in the spring so 

 that a sample cannot always be given attention the day 

 it arrives, and you have the basis for some delays in 

 making reports. 



The real difficulties develop with some of the 

 grasses which may take longer periods of time for 

 germination. Timothy seed requires eight days for 

 germinating. Red top requires at least ten days and 

 is often run for twenty or more by the most careful 

 laboratories. Vetch requires fourteen; the fescues, 

 twenty-one ; and blue-grasses, twenty-eight days for a 

 single test. Perhaps these illustrations may serve to 

 explain some of the physical limitations in reporting 

 the results of seed tests. 



