L. H. Pammel. Seed testing in Iowa. 269 



Seed testing in Iowa. 



By 

 Professor Dr. L. H. Pammel, Arnes, Iowa. 



A number of states in the Union have passed laws regulating 

 the sale of seeds; in some states like Maine seeds can only be sold 

 under a guaranty. The Iowa law is somewhat niore comprehensive. 

 An attempt was made to fix Standards of purity and vitality. Seeds 

 sold must be up to the Standards required by law. Seeds with certain 

 class of weed seeds, like Canada Thistle (Cirsium arvense), Quack 

 Grass (Agropyrura repens), Dodder (Cuscuta epithymum and C. ar- 

 vensis), and some others are only permitted in small traces. A second 

 class of weed seeds, like Sweet Clover (Melilotus alba), Black Medick 

 (Medicago lupulina), Bur Clover (Medicago denticulata), Buckhorn 

 (Plantago lanceolata), Bracted Plantain (Plantago aristata), Evening 

 Catchfly (Silene noctiflora), Dock (Eumex crispus), and Sheep Sorrel 

 (Rumex acetosella), and some others are permitted when the amount 

 is not over 2 percent. Practical experience has shown that in many 

 cases it is impossible to separate all of these weed seeds from clover 

 and alfalfa. In some cases the weed seeds are so nearly like the 

 commercial seed that none of the machines can separate them. There 

 are special devices for separating the Buckhorn by utilizing the fact 

 that the seeds of this plant are mucilaginous when moistened. The 

 great trouble has been that farmers often desire a cheap article and 

 hence seeds are purchased with many weed seeds in them. The 

 growing of clover seed for the market is often an incidental matter. 

 If the crop promises well the f armer harvests the clover crop seed. 



The cleaning of seed is largely a mechanical process, but in 

 some seasons the clover crop is much more weedy than in others, 

 because the red clover may have been winter killed or the drouth 

 of Summer may have influenced the plants in such way that the 

 clover plants are more or lese scattered in the field. Generally 

 speaking clover seed from Iowa has the following impurities, Smart- 

 weed (Polygonum persicaria and P. pennsylvanicu7n), Small Rag- 



