1. Addicott, F. T., andLynch, R. S. 1955. Physiology of abscission. Ann. Rev. Plant Physiol.6: 211–238.
2. Anderson, V. L. 1924. Some observations on the nitrate-reducing properties of leaves. Ann. Bot., Lond.38: 699–706.
3. Andrews, F. S. 1940. Root-top ratio of the Bush Lima Bean as an index of adaptability to ecological conditions. Proc. Amer. Soc. Hort. Sci.37(1939): 752–758.
4. Andrews, F. W., andClouston, T. W. 1937. Section of Botany and Plant Pathology. Rep. Agric. Serv. Sudan1936: 40–41.
5. Armstrong, G. M., andAlbert, W. B. 1931. A study of the cotton plant with especial reference to its nitrogen content. J. Agric. Res.42: 689–703.