Manganese is the most widespread micronutrient problem in the UK. Symptoms are not often seen before the 3-leaf stage and are usually seen on the middle third of the leaf. Typical symptoms in wheat are rows of interveinal white streaks. Barley tends to be more susceptible than wheat, with interveinal brown spots often found in spring barley. However, winter barley is similarly susceptible like wheat.
In cereals, deficiency causes the distinctive green mottling of the leaves. Early symptoms include the loss of the healthy green colour between the veins. This may be followed by yellowing which starts at the leaf tips and margins and progresses inwards, until the entire leaf is chlorotic. This can lead to a curling of the leaf margins, death of the chlorotic areas and premature defoliation.
Monocots are particularly prone to zinc, especially Maize that is very susceptible. Symptoms of zinc deficiency are very distinctive. In maize there may be a light streaking of the leaf followed by a broad whitish band. The leaf edges, midrib and tip remain green. The plants become stunted with short internodes.
Copper is relatively immobile in plant tissue so deficiency symptoms tend to appear initially in young tissues. Severely affected cereals show pale green young leaves, which may become twisted and whitened. Ears may be malformed with full grains at the base, shrivelled grain in the centre and none at the tip.