REFERENCES
- Melsted , S. W. , Motto , H. L. and Peck , T. R. 1969 . Critical Plant Nutrient Composition Values Useful in Interpreting Plant Analysis Data. . Agron. J. , 61 : 17 – 20 .
- Lockman , R. B. 1972 . Mineral Composition of Grain Sorghum Plant Samples. III. Suggested Nutrient Sufficiency Limits at Various Stages of Growth. . Commun. Soil Sci. Plant Anal. , 3 : 295 – 306 .
- Sumner , M. E. 1979 . Interpretation of Foliar Analyses for Diagnostic Purposes. . Agron. J. , 71 : 343 – 348 .
- Epstein , E. 1972 . Mineral Nutrition of Plants: Principles and Perspectives Vol. 412 pp , New York : John Wiley and Sons: .
- Bates , T. E. 1971 . Factors Affecting Critical Nutrient Concentrations in Plants and their Evaluation: A Review. . Soil Sci. , 112 ( 2 ) : 116 – 130 .
- Dow , A. I. and Roberts , S. 1982 . Proposal: Critical Nutrient Ranges for Crop Diagnosis. . Agron. J. , 74 : 401 – 403 .
- Dumenil , L. 1961 . Nitrogen and Phosphorus Composition of Corn Leaves and Corn Yields in Relation to Critical Levels and Nutrient Balance. . Soil Sci. Soc. Am. Proc. , 25 : 295 – 298 .
- Reuter , D. J. and Robinson , J. B. 1986 . Plant Analysis: An Interpretation Manual Melbourne, Sydney, , Australia : Inkata Press: .
- Ramolemana , G. M. 1999 . The Phosphorus and Nitrogen Nutrition of Bambara Groundnut (Vigna subterranea (L.) Verdec.) in Botswana Soils. An Exploratory Study 89 pp Wageningen, , The Netherlands : Wageningen University and Research Centre Liaison Office: . Trop. Resour. Mgt. Papers No. 26
- Brink , M. , Collinson , S. T. and Wigglesworth , D. J. Characteristics of Bambara Groundnut (Vigna subterranea) Cultivation in Botswana. In Proceedings of the International Bambara Groundnut Symposium, University of Nottingham, UK . July 23–25 1997 , UK. UK : University of Nottingham: .
- Sims , D. 1981 . Agro-Climatological Information, Crop Requirements and Agricultural Zones for Botswana Gaborone, Botswana : Land Utilization Division, Ministry of Agriculture: .
- Beynon , S. 1991 . “ The Response of Sorghum to Phosphate Fertilizer in Botswana. ” . In InThe Bulletin of Agricultural Research in Botswana No. 9 67 – 78 . Gaborone, Botswana : Ministry of Agriculture: .
- Ingestad , T. and Lund , A. B. 1986 . Review Article: Theory and Techniques for Steady State Mineral Nutrition and Growth of Plants. . Scandinavian J. For. Res. , 1 : 439 – 453 .
- 1985 . “ SAS. ” . In Statistical Analysis Systems User's Guide Cary, NC : SAS Institute: .
- Ramolemana , G. M. , Maphanyane , G. S. and Wessel , M. Response of Bambara Groundnut to Phosphorus With and Without Irrigation. In Proceedings of the International Bambara Groundnut Symposium, University of Nottingham, UK . July 23–25 1997 , UK. UK : University of Nottingham: .
- Clark , W. M. 1923 . The Determination of Hydrogen Ions Baltimore, MD : Williams and Wilkins Co.: . 3rd Ed.;
- Thomas , G. W. 1982 . “ Exchangeable Cations. ” . In InMethods of Soil Analysis. Part 2. Chemical and Microbiological Properties Edited by: Black , C. A. , Evans , D. D. and White , J. L. Madison, WI : American Society of Agronomy: . 2nd Ed.;
- Smith , P. F. 1962 . Mineral Analysis of Plant Tissues. . Annu. Rev. Plant Physiol. , 13 : 81 – 108 .