Efficiency of check-plot designs in unreplicated field trials
1994
Chandra, S. (Hohenheim Univ., Stuttgart (Germany). Inst. fuer Angewandte Mathematik und Statistik)
Check-plot designs have a lower selection intensity than unreplicated non-check-plot designs if both the number of test lines to be selected (s) and of total plots in the trial (N) are kept constant. For a check-plot design to be more efficient, local control must effectively reduce the plot error variance and increase heritability to such a level that it compensates for the corresponding loss in selection intensity and makes the expected gain from selection at least equal to that in the non-check-plot design. To realize this goal, the required minimum reduction in plot error variance in a checkplot design (relative to that in a non-check-plot design) depends on check-plot frequency, fraction, selected to total and ratio of non-check-plot design plot error variance sigma(2)(o) to genetic variance sigma(2)(g) among test lines. Lower ratio and higher frequency and fraction are found to require a relatively higher reduction in plot error variance in check-plot designs. A condition is derived to show when a check-plot design may never be more efficient.
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