The present investigation was carried out to study the effect of micronutrients on biochemical constituents of Cassia angustifolia. The uses of micronutrients have emerged as an important tool in improving agricultural production. The study was conducted to compare the effects of three micronutrients on the photosynthetic pigments and biochemical constituents in leaves of medicinal plant Cassia angustifolia. The foliar application of micronutrients solutions of CuSO4, FeSO4, ZnSO4 (500, 1000, 1500 mg/l) and commercial micronutrient mixture, Miczink, (0.50, 0.75,1 ml/l) were applied foliarly to the seedlings of 45 DAS (days after sowing) up to the flowering stage at the interval of fifteen days. The physiological analysis of photosynthetic pigments like chlorophyll a, chlorophyll b, proteins and phenols, revealed that there was positive and highly significant increase in all above parameters due to all the concentrations of micronutrients used. The improvement in basic metabolites through micronutrients application may probably lead to enhancement in secondary metabolites content. DW spread plants were considered as control for treatments of micronutrients. Performances of different micronutrients in C. angustifolia indicated that all the micronutrients used have caused statistically significant increase in photosynthetic as well as organic constituents over control. Amongst the different treatments of micronutrients FeSO4, ZnSO4 (1500 mg/l) and Miczink (1ml/l), had shown maximum positive influence on total chlorophyll contents in C angustifolia. While for enhancing phenol contents in leaves, CuSO4 (1000 and 1500 mg/l) emerged best treatment over control.
