between the leaf veins contain so little 
chlorophyll that they turn yellow. This 
yellowing, technically called chlorosis, 
is usually worst on the lowest leaves 
of the plant. The yellowed leaf tissues 
may turn brown or gray and die pre- 
maturely. A zinc-deficient area in a 
bean field will have a yellowish-brown 
color when viewed from a distance. 
Varieties of some crop plants differ 
in their ways of reacting to zinc short- 
age. For example, Russet Burbank, 
alone among all potato varieties grown 
commercially in the West, shows a 
conspicuous stunting of leaves of the 
terminal growth and does not, like 
other potatoes, show yellowing of leaf 
tissues and stunting of lower leaves. 
Varieties of field beans differ consider- 
ably in their reactions. 
Symptoms are often more common 
and more severe at earlier than at later 
stages of growth. A moderate zinc 
deficiency, even though it delays matur- 
ing of corn or bean plants and limits 
their yields, may cause no symptoms 
on new growth of the plants as the 
root systems develop. 
Symptoms of zinc deficiency re- 
semble those of iron, manganese, or 
magnesium deficiency. This deficiency 
can occur together with any one or 
two of the others named, or with all 
of them. 
Diagnosis 
Make sure you diagnose any plant 
abnormality correctly before you 
attempt to control it. The symptoms 
pictured in this leaflet are a good guide 
to diagnosing zinc deficiency, but they 
are not entirely reliable. Laboratory 
tests for determining zinc content of 
soil are not yet suitable for routine 
use, and no quick tissue tests can be 
recommended yet for field use. 
BN-11895 
“Fern leaf,” the foliage abnormality illustrated at the right, results from zinc 
deficiency in just one of the potato varieties grown commercially in the West— 
Russet Burbank. At the left, normal foliage of Russet Burbank. (In other western 
potato varieties, the symptoms of zinc deficiency are yellowing between veins of 
older leaves and stunting of leaves.) 
