Fungous Diseases oe Coeor.vdo Crop Peants 
49 
(5) Follow carefully directions for making spray mixture. Do 
not get it too strong. 
“Niter"’ Injury (Plate XVIIL —The leaves of fruit trees af- 
Plate XVIII. Apple leaf ■with “niter” injury. Note the characteristic bro'w^ning along 
the margins. 
fected by excessive quantities of niter in the soil have a characteris¬ 
tic appearance. The burning and shrivelling of the leaf begins at 
the tip, progresses rapidly along the margin, and finally involves the 
entire leaf. A few limbs, or the whole tree may be attacked. Of all 
our fruit trees, the apple seems to suffer the most. 
Arsenicai, Poisoning. —Headden (“Arsenical Poisoning of 
Fruit Trees,"’ Bulletin 131 (1908) and Bulletin 157 (1910), Colo. 
Agri. Exp Sta.), showed that many cases of death of orchard trees 
in Colorado were due to the action of the arsenic applied to trees 
