Calcium ameliorates photosynthetic capacity, nitrate reductase, carbonic anhydrase, nitrogen assimilation, yield and quality of Cassia sophera L. - a medicinal legume.

Plant biological yield appears to be comparatively low in calcium deficient soils of Aligarh, Western Uttar Pradesh, India. Here, Ca deficiency poses a serious yield and quality limitation for several crops, including various medicinal legumes in this region of India. Cassia sophera L. is an important medicinal herb of great therapeutic value and is used in the modern as well as traditional systems of medicine. In view of the medicinal importance of Cassia sophera L., a hypothesis was designed to determine whether calcium application through soil could enhance the photosynthetic efficiency, enzymatic activities, nitrogen assimilation, yield and quality attributes. The plants were grown in pots containing soil supplied with five levels of calcium, viz. 0, 40, 80, 120 and 160 mg Ca kg(-1) soil (Ca0, Ca1, Ca2, Ca3 and Ca4, respectively) applied as calcium chloride (CaCl2). The performance of the crop was assessed in terms of various growth, physiological, biochemical, yield and quality attributes at 120, 150, 180 and 210 days after sowing. Calcium application proved significantly effective on most of the attributes studied. Of the five calcium levels, Ca3 showed the best results that significantly stimulated most of the attributes studied at the three growth stages.