Yellowing of tea leaves occurs due to the deficiency of:

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

Plants show certain morphological changes due to the absence of a specific element. These morphological changes are indicative of the deficiency of that particular element,which are called $........$ of the element.

Flowering in plants is delayed due to 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:

Premature leaf fall is caused due to the deficiency of