35 



were nearly free from dandelions. Late in the summer, when rains 

 were more frequent, the sprayed plats took on a darker green color 

 and presented a much healthier and more pleasing appearance 

 than the adjoining unsprayed lawns with the rough, mussy dandelion 

 foliage. Weeds, such as mallow, purslane^ dock, and narrow-leaved 

 plantain, which are not as easily killed by the iron sulfate, appeared 

 in the spots where the large dandelions were killed out. 



THE EXPERIMENTS IN 1915. 

 PLAT 1. 



On May 7, 1915, three years after this plat was first sprayed, 

 there were only a few (less than 30) dandelion plants in bloom. 

 However, there were quite a number of young seedling plants appear- 

 ing over the entire plat. At the close of this season, following frequent 

 rains, there were approximately one-fourth as many dandelions 

 in this sprayed area as in the adjoining unsprayed lawn. These 

 plants were mostly young seedlings, and undoubtedly came from 

 wind-blown seeds from plants which seeded heavily in adjoining 

 lawns. 



The experiment to date shows quite conclusively that the dande- 

 lions can be killed during one season's careful spraying, but that 

 the plants may reappear in the lawn from seeds which are constantly 

 " blowing in " from nearby lawns where the pest is permitted to 

 produce seeds. 



PLATS 2 AND 3. 



In the spring of 1915 there were comparatively few dandelion plants 

 (less than 100 in the two plats) which blossomed. These presented 

 a marked contrast to the profuse blossoming of innumerable plants 

 in the adjoining unsprayed lawns (Plate VI). The dandelion 

 plants remaining in the unsprayed plats were single plants, many 

 of them being seedlings. The grass in the sprayed plats showed no 

 injurious effects of the iron sulfate while, on the other hand, it 

 possessed a much greener color than the grass in adjoining areas. 

 In actual practice these sprayed lawn areas would be considered 

 " clean " by the average person, and would receive no special 

 attention. 



It was noted at the close of the previous season that certain lawn 

 weeds other than the dandelions were appearing in the bare spots 

 where the latter had been killed out. Some of these bare spots 



