The N fed plants showed a significant enhancement of capsule number and seed yield plant-1, and nitrate reductase activity, as well as protein and oil yields plant-1, especially upon application of 352 mg N pot-1. Moreover, the effect of basal N was further potentiated following an additional treatment with various GA3 concentrations. | Turk J Bot 32 (2008) 165-170 © TÜB‹TAK Research Note Effects of Nitrogen Fertilisation on Nitrate Reductase Activity, Protein, and Oil Yields of Nigella sativa L. as Affected by Foliar GA3 Application Shoukat Hussain SHAH Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh, 202002 - INDIA Received: Accepted: -4 -5 -6 Abstract: The influence of foliar GA3 application (0, 10 , 10 , or 10 M) on the responses of Nigella sativa L. to various levels of N fertilisation (0, 176, 264, 352, or 442 mg N pot-1) was analysed through 2 pot experiments conducted at the Department of Botany, Aligarh Muslim University, Aligarh, India. The N fed plants showed a significant enhancement of capsule number and seed yield plant-1, and nitrate reductase activity, as well as protein and oil yields plant-1, especially upon application of 352 mg N pot-1. Moreover, the effect of basal N was further potentiated following an additional treatment with various GA3 concentrations. However, in contrast to all other parameters, seed oil content decreased with either treatment. Nonetheless, the combined application of 352 mg N pot-1 and 10-5 M GA3 proved to be maximally stimulative. Key Words: Nigella sativa, nitrate reductase, nitrogen, GA3, seed oil content, seed protein content, seed yield Introduction Nitrogen (N) is the single most important growth limiting factor for crops and, when supplied in the form of urea, has proved to be most instrumental among all major elements in boosting the yield of numerous plants (Kumar et al., 2004; Ashraf & Noman, 2006; Ashraf et al., 2006). The success of N fertilisation mainly arises from the indispensability of N as a plant nutrient, wherein it forms an integral part of biologically critical molecules, such as nucleic acids, structural and catalytic proteins, and chlorophyll, that regulate photosynthesis and crop production (Wu Feibo et al., 1998). Evidently, ample availability of N liberates a .
