376 



FIELD CROP PRODUCTION 



sand. Large grass and legume seeds may best be placed 

 between blotters, while small seeds, like those of redtop 

 and blue grass, are best germinated on top of the blotter. 

 The sand in the box serves as' a reservoir to supply mois- 

 ture to the blotter, thus keeping the seeds moist. Exces- 

 sive evaporation, which results in the rapid drying out of 

 the sand and blotter, may be prevented if the box is covered 

 over with a piece of paper. The temperature at which 

 grass seed germinates best varies with the different grasses. 

 Blue-grass germinates best if the temperature falls to 40° F. 

 during some period of the day with a maximum tempera- 

 ture of 70°. Legumes usually germinate in from 6 to 10 

 days, while grasses require a longer time, blue-grass 

 requiring 28 days. The accompanying table gives the 

 temperature, position of seed in the tester, and length of 

 time required for the test : 



B-B — between blotters. 



T-B— on top of blotter. 



