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

In plants,where does chlorosis occur due to magnesium deficiency?

Grey spots of oat are caused by the deficiency of:

Match the mineral deficiency disorders given in Column $I$ with their symptoms given in Column $II$.

Column $I$ (Disorder)	Column $II$ (Description)
$i$. Chlorosis	$a$. Localised death of tissues in leaves
$ii$. Necrosis	$b$. Premature fall of flowers,fruits and leaves
$iii$. Mottling	$c$. Yellowing of leaves due to absence of chlorophyll
$iv$. Abscission	$d$. Appearance of green and non-green patches on leaves

Choose the correct option from below.

Which mineral deficiency causes the 'Exanthema' disease in citrus plants?

If a plant shows a symptom which could develop due to deficiency of more than one nutrient,how would you find out experimentally,the real deficient mineral element?