192 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



aud is claimed by other investigators to be free from alkali troubles, 

 was the only exception to the finding of definite seep conditions and 

 even in this orchard the second and third foot were found to be 

 sandy and very wet and at the eighth foot another layer of wet sand 

 was encountered. Along the edges of this orchard the alkali showing- 

 was quite marked and in an oblique strip running through the orchard 

 in which most of the trees had died, some of them with rather typical 

 collar rot conditions, the sides of the irrigation furrows showed un- 

 mistakable traces of alkali. It was also noticed that a crop of weeds 

 had sprung up in the area where the trees were affected while the 

 remaining portions of the orchard were quite bare, the cultivation 

 having been the same throughout, indicating that the rising ground 

 water had been sufficient to germinate seeds in the affected areas. 



The orchard formerly owned by Dr. F. R. Smith is one of the 

 oldest orchards in this valley and is located on top of one of the fruit 

 ridges. This orchard is twenty-three years old and has received one 

 hundred and eight heavy sprayings, perhaps the greatest amount of 

 arsenic that has been applied to any orchard in this western country. 

 As Doctor Smith relates, he sprayed until the water ran down the 

 trees and saturated the bands, soaking the ground. For five years 

 he used the Kedzie formula double strength and sprayed seven times 

 a season. The orchard shows no indication of having been injured in 

 any way by this excessive amount of spraying. This amount of 

 poison is far more than would be necessar\' to protect a tree for its 

 entire life under present methods of application. There is no sign 

 of alkali in any part of this orchard, lying as it does on the crest of a 

 narrow ridge, and in this orchard there seems to be the ideal condi- 

 tion for testing the possible effect of arsenic when free from the 

 contaminating influence of alkaline waters, and as yet there is no 

 evidence of injury. In fact, the orchard is in a remarkably healthy 

 condition with the exception of one tree which is subject to overflow 

 from a nearby ditch. 



In the Delta-Montrose District a number of orchards which were 

 pointed out as being affected by arsenical poisoning, were studied. 

 Nearly all of the orchards of this section are located upon high mesa 

 lands. The soils on the surface are usually fertile but vary consid- 

 erably in depth. On boring, the soil augur usually encounters a cal- 

 careous hardpan, or "marl" layer, as it is called, at from eighteen 

 inches to three or more feet from the surface. This layer is from 

 one to two feet in thickness and is often penetrated by the roots of 

 the trees. Throughout this entire district the Jonathan apples are 

 more or less affected and in some orchards a considerable number have 



