Older leaves have ivory-tinted necrotic spots and shreaks coalescing into larger scorched areas; some leaves show pale( faded) yellow chlorosis over whole surface of apical regions.

• 缺钾的大麦叶片：老叶出现灰白色斑点，逐渐连在一起呈烧焦区域，有的叶片黄化一直到叶尖。