80 SEED TESTING 



68. WEIGHT 



Since the amount of food stored in a seed determines the 

 vigor and hardiness of the plant, weighing is an important 

 test in determining the value of seeds. 



Object. To determine the weight of a sample of seeds. 



Method. Weigh out equal quantities of different seeds 

 under inspection, having first removed any impurities. 

 Count the seeds in each portion. The sample showing 

 fewest seeds to a given weight will be the best. 



Another method is to pick from each sample one hundred 

 seeds and carefully weigh them. 



Note. Weight is not always proportional to size. Large seeds 

 are sometimes found in which the kernel is missing or shrunken to 

 very small size. 



69. COLOR AND ODOR 

 Object. To study the color and odor of seeds. 



Young seeds are of a bright, fresh color. Old seeds lose 

 their freshness and become dull colored, sometimes fading 

 and sometimes becoming darker in hue. Most fresh seeds 

 have an agreeable smell and some are truly aromatic. But 

 with age the oils in seeds are apt to become rancid, and so 

 there is often a disagreeable odor about old seeds. Damp 

 seeds also acquire a musty odor. 



Method. Procure various samples of fresh seeds. Com- 

 pare them with old seeds of the same sort, noting the dif- 

 ference in color and brightness as well as the difference in 

 odor. 



Plant old and new seeds of the same sort under conditions 

 favorable for germination. Result? 



