G 
Colorado Experiment Station 
value at the same rate per acre as we did that of the 92% value, the 
yield per acre would be 35.2 bushels. The value of this acre of wheat 
would be $77.44, a loss of $10.56 per acre. With 80 acres of wheat, 
this loss would amount to $844.80. But this does not represent the 
entire loss. By the use of seed low in purity, carrying weed seeds, 
weeds have been introduced into the field, which make cultivation 
more difficult, rob the crop plants of soil nutriment, possibly harbor 
insect and fungous pests, furnish a crop of seeds which infests the 
soil for another year and infests as well the crop seeds taken from 
that field. 
Let us compare the planting value of high grade and low grade 
alfalfa seed. Alfalfa with a germination of 87% and purity of 
98% may be considered standard quality. The actual planting value 
of this seed is (87x98) 87.2%. Let us suppose that it takes 10 pounds 
per acre of this seed at 22 cents per pound. The cost of the seed 
necessary to plant an acre will be $2.20. Seed with the same ger¬ 
mination, but with a purity of 90% will have a planting value of 
(87 times 90) 78.3%. If 10 pounds of standard quality seed were 
used per acre, how much of the inferior quality of seed should be 
used in order to scatter on each square rod the same number of seeds 
per acre? It will require 10.9 pounds per acre which, if sold at the 
same price per pound as the high quality seed, would give an acre 
cost of $2.40. Upon the same basis, alfalfa seed with a germination 
of 60% and a purity of 90%, which is not unusual, will have a 
planting value of (60 times 90) 54% and wdll need to be seeded at 
the rate of 16 pounds per acre, which will give an acre-cost of $3.52. 
These illustrations are taken to show the great necessity of using 
the best of seed; moreover, the great need of having seed tested 
before planting in order to have a guide as to how much seed to 
plant per acre. If the actual planting value is low, more seed will 
necessarily have to be planted per acre to secure a good stand than 
when a standard, high quality of seed is used. 
Every farmer should make it a rule to test for himself, or have 
tested for him, all seed before it is planted. The farmer in the case 
above lost $844.80 on his 80 acres of wheat; most of this might have 
been avoided by using better quality of seed or by planting greater 
amounts per acre of the lower grade of wheat. 
More emphasis should be placed upon the actual planting value 
of seed. This value is' secured by multiplying the percentage of 
germination by the percentage of purity. It is only by making a 
test of the seed that we can know of its planting value. 
It is far better to use some seed as feed rather than seed. If 
a germination test shows the seed to be of low viability, or if it is 
heavily infested with noxious weeds which are difficult of removal, 
surely such seed should be used for some other purpose than seeding. 
