EXERCISE 117 

 PURITY OF FARM SEEDS 



Materials. Samples of any of the smaller seeds, such as the 

 grasses, clover, wheat, and oats. Seeds from local dealers, or from 

 the homes of the pupils, preferred. 



Directions for work. Weigh out a sample of the kind of seed 

 to be tested sufficient to contain several hundred seeds. Spread 

 them out .on the table and with the aid of a hand lens and a 

 needle sort the kinds of seeds found, putting the perfect seeds 

 of the sort which the sample is supposed to represent in one 

 pile, the broken and imperfect seeds in another, bits of earth, 

 chaff, etc. in another, and each kind of weed seeds or unknown 

 seeds in a pile by itself. Count the seeds of each sort of weed, 

 if not too numerous, and calculate the number of each kind of 

 weed seeds per bushel, based upon the weight of the original 

 sample and the weight of a bushel of the kind of seeds examined. 

 If the usual amount of seed per acre were sown from the lot 

 sampled, how many weed seeds per acre would be sown ? 



Weigh the weed seeds and the dirt which was sorted out 

 and calculate the percentage of the sample which is not seed 

 of the variety desired. 



Means for Identification 



BEAL. " Seeds of Michigan Weeds," Bulletin No. 260, Mich. Agr. 



Ex.p. Sta. 



NORTON. " Maryland Weeds," Bulletin No. 155, Md. Agr. Exp. Sta. 

 A named collection of seeds in glass vials. 



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