208 FARM GRASSES OF THE UNITED STATES 



weight of blue-grass and redtop has been 14 Ibs. in 

 most States. This standard was established when it 

 was impossible to clean grass-seed. Ordinary grades 

 are now quoted at from 14 to 20 Ibs. , and fancy or extra 

 fancy seed at 20 to 36 and even 40 Ibs. per bushel. 

 These differences are due almost entirely to variations 

 in the amount of chaff present. 



The most important f adlors aff edling the rate of seed- 

 ing of lawn grasses are the quality of the seed, the time 

 of year, the condition of the soil, and the purpose for 

 which sown. From two to four bushels of seed are 

 commonly recommended. Three or four bushels of 

 good seed, weighing at least 25 Ibs. to the bushel, is 

 the proper amount to sow. Four bushels per acre is 

 at the rate of four-fifths of a quart per square rod, or 

 one quart to 340 square feet of surface, which equals 

 an area 17 by 20 feet. By weight it is 10 ounces per 

 square rod, or one pound to 436 square feet, which 

 equals approximately an area 20 by 22 feet. If 20 

 Ibs. to the bushel is taken as an average weight, and 

 the seed be sown at the rate of four bushels per acre, 

 it requires a half pound per square rod, or one pound 

 on 500 square feet of land, which is an area 20 by 25 

 feet. Quality of the seed as regards purity and vitality 

 must, after all, control the amount sown. Seed con- 

 taining much chaff and of low germinating power 

 should be sown at the rate of six bushels per acre. 

 Where the weight is 30 to 35 Ibs. per bushel, and the 

 percentage of germinable seed is high, the amount 

 need not be over three bushels. Intermediate grades 

 should be sown in proportion. 



In late spring or late fall sow more heavily than in 



