Iron‐manganese‐magnesium interaction in cauliflower

Abstract

Cauliflower (Brassica oleracea L. var. Botrytis) was grown in refined sand in complete nutrient solution and in solutions deficient each in Fe (0.56 ppm), Mn (0.0055 ppm), Mg (0.5 ppm), Fe‐Mn, Fe‐Mg, Pln‐Mg and Fe‐Mn‐Ng. The magnitude of depression owing to Fe deficiency in dry matter, leaf iron, chlorophyll, starch, protein, RNA and the specific activities of catalase and peroxidase was mitigated, to variable extent, by the combined deficiencies of Fe‐Mg, Fe‐Mn and Fe‐Mn‐Mg. The depression in aldolase. activity in iron deficiency became more pronounced by the combined deficiency of Fe‐Mn and Fe‐Mn‐Mg. Hill activity per mg chlorophyll was least in Mn deficiency, its activity and those of Mg‐ATPase and RNAse uhich were enhanced by Fe deficiency alone, were depressed by the combined deficiencies of Fe‐Mn, Fe‐Mg and Fe‐Mn‐Mg. In the latter two treatments and in Mg deficiency, the pyruvate kinase activity was also depressed.