66 CONTROL SERIES No. 86 



Weed Seeds 



Weed seeds were found in 46 of the lots, or 44.23%. One packet of Bachelor 

 Buttons contained .97% Weed Seeds, while a packet of Verbena contained .8%. 

 A packet of Ageratum contained a total of 38 weeds (.60% by weight), repre- 

 senting 9 different genera,, including 17 individual seeds of Crab Grass, which is 

 classed as a noxious weed in many states. These, however, were the extreme 

 cases, as some were found to be entirely free of weed seeds. 



Inert Matter 



Of the 104 lots, a total of 99, or 95.19%, contained Inert Matter of one kind or 

 another. 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 contained 17.42% of such materials. The presence or absence of 

 impurities may be due in some cases to the ease with which the seeds can be 

 cleaned. Thus Ageratum might be expected to contain a high percentage of 

 Inert, since much of the Inert Material is of the same shape and weight as the 

 seed itself. 



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-nine, or 37.50%, contained 

 seeds of other crop plants. One packet of Ageratum ranked high in Other Crop 

 Seed content with 2.74%. A packet of Kochia contained 28 crop seeds, repre- 

 senting 7 genera; a packet of Marigold contained 11 crop seeds, representing 

 10 genera; while another lot of Ageratum was found to have seeds of 11 

 different genera, with a total of 24 seeds. 



The Weed Seeds and Other Crop 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 either that they were placed there intentionally or that they entered 

 through the repacketing process or through careless harvesting and handling 

 methods. This may also be true of the Inert Matter found. 



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. After the purity tests were completed, the samples 

 were turned over to Professor Clark L. Thayer of the Department of Floricul- 

 ture, who conducted tests in the field to determine the actual quality and to 

 check the trueness-to-name. 



Field Tests 



The field tests show that in the majority of samples germination was satis- 

 factory. However, in seven cases the seed failed to germinate and in a few 

 cases germination was extremely poor. Due to the late date of planting, certain 

 seeds, such as sweet peas, did not give good results. 



As far as possible trueness-to-type or variety was determined, but since many 

 lots were described as mixtures or did not carry varietal names, a wide range in 

 color and form was permissible. 



It will be noted that comparatively few of the novelties and named varieties 



