The efficiency of incomplete block designs in National List and Recommended List cereal variety trials

SUMMARY Use of generalized lattice designs instead of complete block designs in 244 cereal variety trials grown in the U.K. since 1975 has resulted in an average reduction of 30% in variances of varietal yield differences. The lattice designs were most effective when the number of varieties was more than 50 but worthwhile reductions in variance, averaging about 24%, were obtained in trials with fewer than 20 varieties. The data also provide guidance on the choice of block size and the potential for improvement by neighbour methods.

[1]  M. S. Bartlett,et al.  Nearest Neighbour Models in the Analysis of Field Experiments , 1978 .

[2]  W. B. Mercer,et al.  The Experimental Error of Field Trials , 1911, The Journal of Agricultural Science.

[3]  H. F. Smith.  An empirical law describing heterogeneity in the yields of agricultural crops , 1938, The Journal of Agricultural Science.

[4]  C. S. Moore,et al.  Reduction of Experimental Error in Perennial Crops,Using Adjustment by Neighbouring Plots , 1976, Experimental Agriculture.

[5]  O. Mayo,et al.  Nearest Neighbour (Nn) Analysis of Field Experiments , 1983 .

[6]  S. Pearce.  The Conduct of ‘Post-Mortems’ on Concluded Field Trials , 1976, Experimental Agriculture.

[7]  F. Yates.  THE RECOVERY OF INTER‐BLOCK INFORMATION IN VARIETY TRIALS ARRANGED IN THREE‐DIMENSIONAL LATTICES , 1939 .

[8]  E. Williams.  ITERATIVE ANALYSIS OF GENERALIZED LATTICE DESIGNS , 1977 .

[9]  H. D. Patterson,et al.  A new class of resolvable incomplete block designs , 1976 .

[10]  R. Kempton,et al.  The Use of Neighbouring Plot Values in the Analysis of Variety Trials , 1981 .

[11]  H. D. Patterson,et al.  Block designs for variety trials , 1978, The Journal of Agricultural Science.

[12]  S. Pearce.  Randomized blocks and some alternatives: a study in tropical conditions. , 1980 .

[13]  H. D. Patterson,et al.  The effect of block size on the errors of modern cereal experiments , 1963, The Journal of Agricultural Science.

[14]  F. Yates.  A new method of arranging variety trials involving a large number of varieties , 1936, The Journal of Agricultural Science.

[15]  J. Besag.  Errors‐In‐Variables Estimation for Gaussian Lattice Schemes , 1977 .