1919.] PUBLIC DOCUMFAT — No. 31. 43a 



leaves, though twelve types were tested, including most of 

 the common garden plants and several kinds of trees. When 

 applied at 1 to 20 no injury to any foliage was observed. 



In such tests as here reported for Kling Kill Insecticide, 

 Sylpho-Nathol, Nature's Plant Food and Plant Lice Killer, 

 attention should be called to the fact that tests of any material 

 made during only one season, and, of course, on a relatively 

 small scale, should not be regarded as conclusive, but merely 

 as indicating the probable value of the material. Frequently, 

 too, manufacturers, after the tests of one season, change or 

 modify their formulas so that tests another year might give 

 different results for this reason. 



A series of parallel tests was conducted during the summer 

 of 1918 with home-made Bordeaux mixture, Pyrox and Insecto, 

 to determine their value against potato pests. Nicotine 

 sulfate 40 per cent in 1 to 800 dilution was added to each of 

 these during the potato plant louse period of activity. The 

 Insecto had rather poor suspension ciualities as compared 

 with the other two, giving poor distribution on the plants, 

 and frequently clogging the nozzle. The best distribution 

 was obtained with the home-made Bordeaux, but Pyrox was 

 not far behind in this regard. The flea beetles were well 

 controlled by all three materials, and the nicotine sulfate 

 combined without difficulty with them all and was efficient 

 against the plant lice. Although not entomological in nature, 

 it may be stated that the rows to which the home-made 

 Bordeaux was applied kept green and alive the longest and 

 produced the largest crop; those treated with Pyrox, next. 



