Symptoms
Affected plants show spindly, sparse growth.
On the older leaves, V-shaped yellowing on the leaf tips progresses towards the base, so that leaves finally turn uniformly pale green/yellow.
Stalks get a reddish discoloration.
The oldest leaves on the bottom become necrotic.
Reasons
Nitrogen deficiency
Sulphur deficiency can cause similar chloroses but starts on the younger leaves, whereas paling due to N deficiency is detectable on older leaves first.