Cheng, W., Sims, D.A., Luo, Y., Johnson, D.W., Balls, J.T. and Coleman, J.S. 2000. Carbon budgeting in plant-soil mesocosms under elevated CO2: locally missing carbon? Global Change Biology 6: 99-109.

Gong, X.Y., Schäufele, R., Lehmeier, C.A., Tcherkez, G. and Schnyder, H. 2017. Atmospheric CO2 mole fraction affects stand-scale carbon use efficiency of sunflower by stimulating respiration in light. Plant, Cell and Environment 40: 401-412.

Lakshmi, N.J., Vanaja, M., Yadav, S.K., Maheswari, M., Archana, G., Patil, A and Srinivasarao, C. 2017. Effect of CO2 on growth, seed yield and nitrogen uptake in sunflower. Journal of Agrometeorology 19: 195-199.

Lakshmi, N.J., Vanaja, M., Yadav, S.K., Maheswari, M., Patil, A., Prasad, C.H., Satish, P. and Venkateswarlu, B. 2014. Differential improvement in transpiration efficiency of C3 and C4 crop plants under elevated CO2 conditions. Indian Journal of Agricultural Sciences 84: 103-105.

Lehmeier, C.A., Schaufele, R. and Schnyder, H. 2005. Allocation of reserve-derived and currently assimilated carbon and nitrogen in seedlings of Helianthus annuus under subambient and elevated CO2 growth conditions. New Phytologlist 168: 613-621.

Marc, J. and Gifford, R.M. 1984. Floral initiation in wheat, sunflower, and sorghum under carbon dioxide enrichment. Canadian Journal of Botany 62: 9-13.

Mark, U. and Tevini, M. 1997. Effects of solar ultraviolet-B radiation, temperature and CO2 on growth and physiology of sunflower and maize seedlings. Plant Ecology 128: 224-234.

Miyagi, K.-M., Kinugasa, T., Hikosaka, K. and Hirose, T. 2007. Elevated CO2 concentration, nitrogen use, and seed production in annual plants. Global Change Biology 13: 2161-2170.

Morison, J.I.L. and Gifford, R.M. 1984. Plant growth and water use with limited water supply in high CO2 concentrations. II. Plant dry weight, partitioning and water use efficiency. Australian Journal of Plant Physiology 11: 375-384.

Pal, M., Chaturvedi, A.K., Pandey, S.K., Bahuguna, R.N., Khetarpal, S. and Anand, A. 2014. Rising atmospheric CO2 may affect oil quality and seed yield of sunflower (Helianthus annuus L.). Acta Physiologiae Plantarum 36: 2853-2861.

Tang, S., Xi, L., Zheng, J. and Li, H. 2003. Response to elevated CO2 of Indian mustard and sunflower growing on copper contaminated soil. Bulletin of Environmental Contamination and Toxicology 71: 988-997.

Vanaja, M., Yadav, S.K., Archana, G., Lakshmi, N.J., Reddy, P.R.R., Vagheera, P., Razak, S.K.A., Maheswari, M. and Venkateswarlu, B. 2011. Response of C4 (maize) and C3 (sunflower) crop plants to drought stress and enhanced carbon dioxide concentration. Plant, Soil and Environment 57: 207-215.

Zerihun, A., Gutschick, V.P. and BassiriRad, H. 2000. Compensatory roles of nitrogen uptake and photosynthetic N-use efficiency in determining plant growth response to elevated CO2: Evaluation using a functional balance model. Annals of Botany 86: 723-730.