84 INJURIOUS INvSECTS OF 1904. 



3. Buy a few cents worth of ferrocyanide of potash, dissolve it 

 in water. To a httle of the Bordeaux mixture in a glass or crock- 

 ery dish add a few drops of the ferrocyanide of potash solution ; if 

 a brown color appears, the Bordeaux is acid, and more lime should 

 be added, and the test repeated. 



These frequent applications of Bordeaux, if it is properly made 

 and properly applied, will keep the blight in check, and will in a great 

 measure also prevent insect attack. The insecticidal qualities of the 

 mixture could be bettered by adding four ounces of Paris Green (or 

 one gallon of arsenate of lead) to every fifty gallons of Bordeaux. 



PRELIMINARY REPORT UPON WORK AGAINST THE 

 DESTRUCTIVE LEAF HOPPER. . 



This injurious insect and its work in nurseries were discussed 

 in the report of last year, and it was then announced that an active 

 campaign against.it would be inaugurated in the summer of 1904. 

 In the meantime, having met with Professor Stedman of the Missouri 

 Station, I was struck by his description of a spraying machine, planned 

 to spray four rows of nursery trees at the same time, which he had 

 had made in his state. He very courteously gave me a general de- 

 scription of the outfit, the plans for which I have followed in Minne- 

 sota in a general wav. 



THE CART. 



It seemed, however, desirable to bring the reservv./ir below the plat- 

 form in order to better balance the cart, and since three or four- 

 year-old trees in Minnesota are not as tall as trees of the same age 

 in Missouri, we found it unnecessary to make the cart as high as the 

 one used in the state south of us. Therefore, while Stedman's plan 

 was followed in the main, the cart we constructed dififers , from his in 

 many minor details. This outfit is intended for use in large nurseries, 

 and on level ground. 



