Mineral Nutrition Question 28
28. Grey spots of oat are caused by deficiency of
[2003]
(a) $Fe$
(b) $Cu$
(c) $Zn$
(d) $Mn$
Show Answer
Answer : d
Hints & Solution
(d) Grey spots of oat are caused by deficiency of Manganese. In oats, $Mn$ deficiency produces a condition called ‘grey speck’ with occurs in patches. Oats become pale green and young leaves have spots or lesions of grey/brown necrotic tissue with orange margins. These lesions will coalesce under severe Mn deficient conditions. Plants are weak, stunted, floppy and pale green-yellow and appear water-stressed even when adequate soil moisture is available. Close examination of the leaf may show slight interveinal chlorosis. The distinction between green veins and yellow interveinal areas is poor. Symptoms can be confused with red leather leaf, which is favoured by prevailing high humidity in high rainfall areas. Symptoms can also be mistaken for take-all.
