41 



of narrow-leaved plantain, also some patches of white clover and 

 yellow trefoil were to be found scattered over both plats as well as 

 in the adjoining lawn. With the exception of Section D, which was 

 reseeded with grass seed, the condition of these plats plainly empha- 

 sized the great need of after-treatment measures to follow the 

 spraying. 



PLAT 4. 



The appearance of the lawns included in this plat, one year after 

 the first spraying with the power sprayer, gave unmistakable evi- 

 dence that the extent of blossoming had been very materially reduced. 

 A large majority of the old plants had been killed. Nevertheless, 

 there were many young plants in certain parts of the sprayed area. 

 In the light of previous experience it was plainly evident that the 

 spraying operations on this plat were discontinued too early in the 

 season to derive the greatest benefit from the treatment. Certainly, 

 the plants should have been forced into the winter without foliage. 



PLAT 5. THE ROBINSON LAWN. 



In the spring of 1918 a small number of dandelion plants were 

 forming blossom buds, and several had blossomed when the owner 

 made an application of the spray solution. Blooming was thereby 

 prevented and, so far as could be determined, there was no increase 

 in the number of dandelions present in the lawn this season. 



THE EXPERIMENTS IN 1919. 

 PLATS 1, 2 AND 3. 



At the beginning of this season, seven, six and five years, respec- 

 tively, from the time of the first spraying, it was plainly evident 

 that there were as many dandelions in these sprayed plats as in the 

 adjoining unsprayed lawns. It seemed to be plainly demonstrated 

 that, where the sprayed lawns are adjoined by unsprayed lawns 

 infested with dandelions, it will be necessary to resort to spraying 

 about every third season in order to keep dandelions under control. 



PLAT 4. 



In June of this season, two years after spraying, it was obvious that, 

 in certain restricted areas adjoining buildings or sheltered by shrub- 

 bery, the old dandelion plants had been killed out; only an occasional 



