PLATE i 
A. —Head of nematode-infected Nebraska Hybrid wheat. The badly distorted flag 
leaf is interfering with the natural emergence of the head from the boot. 
B. —Galls on the stem of Black Winter emmer. 
C. —Gall on the leaf of Black Winter emmer. 
D. —Leaf markings, an early symptom of the nematode disease. Some of these show 
slight discoloration, giving a mottled appearance to the leaf. The split leaf 
shows a more advanced stage of this symptom. 
E. —Prelude spring wheat affected by the nematode disease due to sowing gall-infested 
seed. 
F. —Healthy Prelude spring wheat grown from uninfested seed sown at the same time. 
( 956 ) 
