Abstract
Seeds of Cassia angustifolia Vahl treated with different concentrations (0%, 0.1%, 0.15%, 0.2%, and 0.25%) of a fungicide, Mancozeb, were sown in field conditions in order to study the effect of the stress caused by this fungicide on pigment concentration and the protein and sennoside contents of the plant. Protein content and pigment concentration increased at 0.10% dose of Mancozeb, but higher doses caused a significant decline in comparison with the control. Application of Mancozeb resulted in a considerable dose-dependent reduction in the contents of sennoside a (nearly 7-32% reduction in young leaves, 14-36% in mature leaves and 8-24% in pods) and sennoside b (about 11-36% reduction in young leaves, 5-38% in mature leaves and 5-30% in pods), thus affecting indirectly the therapeutic property of the plant.