Grey spots of oat are caused by the deficiency of:

Deficiency of which mineral element causes the dormancy of lateral buds?

$A$ plant is supplied with urea but suffers from a deficiency of nitrogen. Which of the following symptoms will it exhibit?

Deficiency of copper causes:

Deficiency symptoms of an element tend to appear first in young leaves. It indicates that the element is relatively immobile. Which one of the following elemental deficiencies would show such symptoms?

Flowering in plants is delayed due to the deficiency of $................$.