New York Agricultural Experiment Station. 385 



foreign countries but till recently this method has rarely been used in 

 orchards. Within the last few years dusting has come to be used 

 as a substitute for spraying in orchard practice in certain portions 

 of America. Not only are paris green, sulphur, etc., applied in this 

 way but methods have been devised for preparing what is called dry 

 bordeaux mixture which is dusted upon the trees as a substitute for 

 the well known liquid bordeaux mixture. 



The adherents of dust spraying are found mostly in Illinois, Mis- 

 souri, Kansas and Arkansas. Its claim to attention lies in its great 

 saving of labor and expense. An outfit consists simply of a machine 

 mounted in a one-horse wagon. Only two men are needed to run the 

 largest outfits, and a much larger area can be covered in the same 

 time than by common spraying methods. The dust outfit is light 

 and can be easily used in hilly orchards, and also on wet ground 

 when heavy tanks of liquid could not easily be moved about the 

 orchard. The apparatus applies the dry bordeaux mixture, paris 

 green or other substances in the form of fine, dry powder. In this 

 form insecticides are effective in combating the codling moth and 

 other insects with biting mouth parts, but it is generally held by 

 good authorities that the dry bordeaux mixture is less effective than 

 the liquid bordeaux mixture for controlling fungus diseases, such as 

 apple scab, etc. 



The dust spray can probably be used to better advantage in the 

 west, where the climate is comparatively dry, than in New York 

 State, where the frequent rains would wash the dust off. Bordeaux 

 mixture applied in the liquid form dries on and can often be seen on 

 the leaves at the end of the season. So also does arsenate of lead. 



Even in the west the advisability of the use of the dust spray is 

 by no means generally accepted. In New York State the method 

 has been little tested and barring its well-known use already referred 

 to in the application of paris green, sulphur, etc., the attitude toward 

 it is one of extreme conservatism. At the present writing the use of 



