PEACH MILDEW. 
By O. B. WHIPPLE. 
The phenomenal growth of the peach industry in that part of 
Colorado west of the Continental Divide is due, to a certain extent, 
at least, to the absence of insect pests and fungus diseases. While 
it is probable that our growers will never have the large array of 
these pests, which are common in many other regions, to contend 
with, we cannot hope to be entirely immune from such attacks. 
From a business standpoint, then, we should be constantly on the 
lookout for anything in the nature of a pest, so that it may be 
studied and means devised for its control before its attacks become 
serious. 
Peach mildew has made its appearance in a few orchards and 
appears to be spreading. While no great amount of damage has 
yet been done, some of the growers are beginning to spray their 
trees for the control of the disease. 
It is the purpose of this Bulletin to point out the nature of the 
disease and describe some of the means of combating it which have 
been used in other states. The Experiment Station has had no 
opportunity as yet to conduct experiments of this kind, but there is 
no*reason to suppose that these remedies will fail in Colorado if 
properly made and applied. 
The injury in Colorado is due to a fungus which attacks leaves, 
twigs and fruit alike. It appears on the fruits while they are yet 
small and immature, often causing them to fall prematurely. Its 
first appearance is indicated by a musty or frost-like patch upon the 
surface. When well established, the spots become almost pure 
white; the color being due to the mycelium and its fruiting 
branches, which overrun the surface upon which the fungus estab¬ 
lishes itself. The flesh of the fruit becomes hard under these spots 
and the skin takes on a brown or dead color. The appearance upon 
the twig is very much the same, it being very conspicuous as white 
blotches along the twigs; the underlying bark becoming chy anc 
brown. Where the attack is very severe the leaves fall, the bark be¬ 
comes shriveled, and the young tips often assume a curved position. It 
