TESTING THE GERMINATION 283 



in school or at home 1 . Freedom from weed seeds is equally 

 as important as freedom from undesirable mixtures, as many 

 of the worst weeds are often introduced in grass and clover 

 seed. 



350. Germination Test. As the germination of 

 grass seed is often low, it is well to make a germ- 

 ination test of the seed before sowing or before 

 purchasing it in quantity. A simple germinator may 

 be made from two plates and two pieces of blotting paper 

 or cloth, as shown in Fig. 90. The cloths should be dampened 

 and a definite number of seeds, one hundred or two hundred, 

 placed between them. The second plate should then be put 

 on as a cover and the 

 germinator set in a 

 moderately warm 

 place, where there will 

 not be any marked 

 change of temperature 

 during the day or 



night. The germinator Fig . 90 . Plate germinator for testing 



should be examined 



occasionally to see that the cloths do not dry out. In 

 about ten days, trie seeds which show strong germi- 

 nation should be counted and the percentage of germination 

 figured. If it is low, the seed should not be sown at all, or 

 the rate of seeding should be increased sufficiently to supply 

 the proper quantity of germinable seed. No sample which 

 shows a low percentage of germination or any considerable 

 proportion of impurities should be purchased. It does not 

 pay to buy any but the best quality of grass and clover seed. 



^Farmers' Bulletin 428, "Testing Farm Seeds in the Home and in the 

 Rural School," gives directions for testing all the more important forage crop and 

 grain seeds, with illustrations of these seeds and the more common impurities which 

 are found in them. Farmers' Bulletin 382, "The Adulteration of Forage- 

 Plant Seeds," is also a valuable aid to the making of purity tests. 



