The deficiency of this micronutrient results in little leaf disease.

In a $Citrus$ plantation,all the plants were found to be suffering from the die-back disease,and spraying of fungicides was of no help. This problem was due to the deficiency of:

Interveinal chlorosis of leaves is caused by the deficiency of

Deficiency symptoms of mineral elements appear first in young leaves. - $P$
Deficiency symptoms of mineral elements appear first in senescent (older) leaves. - $Q$
$P$ and $Q$ are respectively:

Symptoms of manganese deficiency can be overcome by the use of

Grey spots of oat are caused by the deficiency of which element?