Interveinal chlorosis of leaves is caused by the deficiency of

$A$: Manganese toxicity causes brown spots,chlorotic veins,and inhibition of calcium translocation to the shoot apex.
$R$: Toxic effects may be due to direct excess of micronutrients or their interference in the absorption and functioning of other nutrients.

It is observed that the deficiency of a particular element shows its symptoms initially in older leaves and then in younger leaves. Name two elements that are highly mobile and two that are relatively immobile.

Rapid deterioration of root and shoot tip occurs due to the deficiency of

The deficiency of molybdenum induces

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