82 CONTROL SERIES No. 96 



Mechanical Purity 



In an effort to obtain definite information as to the extent to which flower 

 seeds, particularly those sold in sealed paper packets, carried impurities, a careful 

 examination was made of each lot. Purity results for seed tested in the field but 

 not including 22 samples which arrived too late for planting but were analyzed 

 in the laboratory will be found in the table. 



Of the 172 lots of flower seeds, nineteen or 11.04% were free of any im- 

 purities whatever. To state it another way, 153 lots or 88.96% contained im- 

 purities in the form of weed seeds, other crop seeds, seeds of plants other than 

 the one in question, or inert materials consisting of fine chaff, dust, stems, floral 

 parts, grit, or pieces of earth. 



The purity percentage was found to vary from 63.88% in the case of one 

 Ageratum to 100% in the cases of one Aster, one Calendula, two Candytufts, one 

 Centaurea, one Cosmos, one Euphorbia, one Gourd, two Larkspurs, one Moon- 

 flower, five Morning Glories and three Nasturtiums. 



Weed Seeds 



Weed seeds were found in 56 of the lots, or 32.56%. One packet of Bachelor 

 Buttons and one packet of Pinks each contained .07% of weed seeds while a 

 packet of Stocks contained 2.08%. Various percentages were encountered between 

 the two extremes given, with most of the packets containing only a small portion 

 of weed seeds. 



Inert Matter 



Of the 172 lots, a total of 153 or 89.53% contained inert matter of one kind 

 cr another. Two packets of Ageratum carried the highest percentage, probably 

 due to the fact that the impurities were of the same general size and weight as 

 the seed itself. One packet carried 35.24% and the other 21.26%. The presence 

 or absence of impurities may be due in some cases to ease of cleaning. 



Other Crop Seed 



Many of the packets contained seeds of flowers other than the kind under 

 consideration, as well as seeds of field crops. Thirty, or 17.44%, contained seed 

 of other crop plants. One packet of Stocks and one packet of Portulaca each 

 ranked high in this particular, with "other crop seed" in one of them 6.00% 

 and the other 3.45%. Also two packets of Verbena carried 2.22% and 

 1.08% respectively. 



The other crop seeds as well as the weed seeds found in the various packets 

 may be accounted for in several different ways. Since some of the "extra" seeds 

 were kinds that are not generally found growing with flower seeds in the fields, 

 it appears that they were either placed there intentionally or that they entered 

 through the repacketing process or through careless harvesting and handling 

 methods. Inert matter found may also be accounted for by the same reasoning. 



Germination 



No germination tests were made in the laboratory on any of the lots collected, 

 since many of the packets contained too small a quantity of seed for both field 

 and laboratory tests. Remarks on germination observed in the field test are 



