Blotchy irregular interveinal fading and orange-yellow chlorosis of older leaves, margins culed and sometimes scorched;younger leaves remaining green.

• 甜菜锰中毒：带有不规则斑点的叶脉间褪色，老叶变为桔黄色，边缘卷曲，有时枯萎，幼叶保持绿色。