72 SEEDS AND FRUITS 
stood. Some seeds may retain their vitality for centuries, but 
most seeds lose it ina few years. The length of time during which 
seeds retain their vitality is called their longevity. Most agri- 
cultural seeds can be stored two or three years without much loss 
of vitality, and some, when stored a much longer period, may 
contain a large number of live seeds. One investigator found 
that 50 per cent of samples of Red Clover seeds germinated after 
being stored in bottles for 12 years; and in samples of the seeds 
of Pigweed, Sheep Sorrel, Black Mustard, and Pepper Grass, 
stored in the same way, a large percentage germinated after a 
storage of 25 years. In samples of White Sweet Clover seeds, 
which have well mod‘fied seed coats, 18 per cent have germinated 
after a storage of 50 years. There is good evidence that some 
of the leguminous seeds may retain their vitality for more than 
a century. Many of the weed seeds when buried in the soil can 
retain their vitality for many years and then germinate when 
conditions become favorable. 
The longevity of seeds depends so much upon the conditions 
under which the seeds were grown, maturity when collected, and 
methods of storing, that statements as to how old any kind of 
seeds may be and still be safe for planting are not reliable. Old 
seeds are often preferable to new ones grown under unfavorable 
conditions. Seeds from poorly developed plants, although sim- 
ilar In appearance to those produced under favorable conditions 
and giving a high percentage of germination soon after harvest, 
decline rapidly in vitality, often being worthless at the next plant- 
ing season. For example, Cabbage seeds eight years old may 
germinate 70 or 80 per cent, while some only three years of age 
but grown in an unfavorable year may germinate less than 40 
per cent. Seeds collected green may germinate well after proper 
curing but they have a short longevity. 
The longevity of seeds depends probably more upon dryness 
than any other factor. For this reason the place of storage 
should be dry and the seeds should be cured before they are 
stored by placing them in a dry airy place. Experiments show 
that. Corn collected soon after maturity and properly cured and 
stored gives a much higher percentage of germination the next 
season than Corn allowed to stand in the shock, or taken from the 
crib. Comparative! germinative tests of seeds stored in different 
1 Bulletin 58, Bureau of Plant Industry, U. 8. Dept. of Agriculture. 
