Which of the following mineral deficiencies may cause a reduction in the growth of leaves?

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.

It is observed that the deficiency of a particular element shows its symptoms initially in older leaves and then in younger leaves. How is the aspect of mobility of elements important to horticulture and agriculture?

If the size of fruits diminishes in plants,which mineral ion should be added to the soil?

Browning of cauliflower takes place due to deficiency of which one of the following elements?

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: