Variability among experimental plots may be a relevant problem in field genotype experiments, especially when a large number of entries are involved. Four field trials on 24 durum wheat genotypes were conducted in 2013/14 in order to evaluate the efficiency of Incomplete Block, Alpha and Augmented designs in comparison with the traditional Randomized Complete Block Design (RCBD). The results showed that the RCBD can be replaced by an Alpha design, which provides better control of variability among the experimental units when the number of treatments to be tested in an experiment exceeds twenty. The ranking of the genotypes across the four designs was not constant.
Abd El-Shafi M.A. (2014): Efficiency of classical complete and incomplete block designs in yield trial on bread wheat genotypes. Research Journal of Agriculture and Biological Sciences 10(1): 17-23.
Akaike H. (1974): A new look at the statistical model identification. IEEE Transactions on Automatic Control 19: 716-723.
Bose R.C., Nair K.R. (1939): Partially balanced incomplete block designs. Sankhya 4: 337-372.
CropStat for Windows ver.7.2 (2007): International Rice Research Institute.
Federer W.T. (1956): Augmented (or Hoonuiaku) designs. The Hawaiian Planters’ Record. LV(2): 191-208.
Federer W.T., Raghavarao D. (1975): On augmented designs. Biometrics 31: 29-35.
Gendex (2015): Gendex DOE Toolkit. http://designcomputing.net/gendex/ Gomez, K.A., Gomez A.A. (1984): Statistical Procedures for Agricultural Research, 2nd ed. Wiley, New York.
Khan, M.I., Ali Shah S.A., Khan M., Ullah K., Ullah R., Khatak S.I. (2015): Comparative efficiency of alpha lattice design and complete randomized block design in wheat, maize and potato field trials. Journal of Resources Development and Management 11: 115-117.
Lin, C.S., Poushinsky G. (1983): A modified augmented design for an early stage of plant selection involving a large number of test lines without replication. Biometrics 39: 553-561.
Masood, M.A., Farooq K., Mujahid Y., Anwar M.Z. (2008): Improvement in precision of agricultural field experiments through design and analysis. Pakistan Journal of Life and Social Science 6: 89-91.
Patterson, H., Williams E.R. (1976): A new class of resolvable incomplete block designs. Biometrika 63: 83-92.
R Core Team (2014): R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL http://www.Rproject.org/.
Stringer J.K., Smith A.B., Cullis B.R. (2012): Spatial analysis of agricultural field experiments. In: K. Hinkelmann (Ed.), Design and analysis of experiments, Vol 3, Special designs and applications: 109-136.
Stroup W.W., Baenzinger P.S., Mulitze D.K. (1994): Removing spatial variation from wheat yield trials: a comparison of methods. Crop Science 86: 62-66.
Williams, E.R., John J.A. (1989): Construction of row and column designs with contiguous replicates. Applied Statistics 38: 149-154.
Yates, F. (1936): A new method of arranging variety trials involving a large number of varieties. Journal of Agricultural Science 26: 424-455.
Yau, S.K. (1997): Efficiency of alpha-lattice designs in international variety yield trials of barley and wheat. Journal of Agricultural Science, Cambridge 128: 5-9.