The quality of seeds sold in Iowa has improved greatly since the investigations of the Iowa Agricultural Experiment Station disclosed that much of the clover, alfalfa and timothy seed sold in the state lacked in vitality and purity. Following the publication of Bulletin No. 88, “The Vitality, Adulteration and Impurities of Glover, Alfalfa and Timothy,” the state legislature, in 1908, passed a pure seed law, which became generally known as the “Iowa Seed Law,” and has been incorporated into somewhat similar laws in other states. Under that law seed conditions have become better. In the tests made by the botanical section of the Iowa experiment station in 1910, 1911, 1912 and 1913, cases of adulteration were few. The presence of such noxious weed seeds as dodder, Canada thistle, and the like, was much less frequent than formerly. In these years there was also a greater demand from farmers for pure seeds and dealers selling in Iowa made more effort to offer seeds free from impurities and strong in vitality.

The general results of the seed analyses for the years 1910- 1913, inclusive, are presented in this bulletin. This phase of the botanical work, since the passage of the Iowa seed law, has grown greatly. During the year 1906 the botanical section examined 413 samples; in 1907, 386; in 1908, 137; in 1909, 186; in 1910, 286; in 1911, 410; in 1912, 550; in 1913, 1058. A part of this large increase during the winter and spring of 1912 and 1913 was due to the fact that samples of seeds were examined gratuitously for seedsmen and small dealers, as well as for the farmers in the state. A few cases of adulteration of seed came to the notice of the section in this period where sweet clover was adulterated with alfalfa, and where alfalfa seed was mixed with sweet clover. Owing to the high price of sweet clover, it is hardly possible that the sweet clover is an intentional adulterant.