Relationship between cation exchange capacity of roots and mineral composition of plant tops as influenced by age

Abstract

Maize (Hy-Ganga-101) and french bean (Waghya) were grown in pots using soil collected from Agricultural College Farm, Poona. Plant tops and roots were collected periodically. Plant tops were analysed for calcium, magnesium and potassium, and the cation-exchange capacity of the roots was determined. The object was to study the relationship between root CEC and mineral composition of plant tops as influenced by age. The results can be summarised as follows: (i) Age of plant influenced root CEC of maize and french bean. In maize, root CEC increased upto the 30th day and gradually decreased till maturity, whereas root CEC of french bean increased upto flowering stage and decreased thereafter till maturity. (ii) The cation content of the tops of maize and french bean did not show definite significant relationships with root CEC according to Donnan distribution of monovalent and divalent cations when the entire life period of the plants was considered. The probable reasons for this non-significant relationships are discussed.