الفهرس 
الفصل الأول : الإطار العام للبحثيوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
It is important for the crop scientists to have knowledge on field plot techniques, the study of size and shape of plot best studied for particular type of experiment .It is of utmost importance to use the most efficient shape, size and arrangements of plots in particular experiment for obtaining the reliable results .
In practice, field experiments focus mainly on the significance of treatment differences even if the soil is heterogeneous .All the other valuable experiment all conditions are neglected .Little attention, if any is given to possible advantages of detailed result analysis
The objectives of the present study were to estimate the optimum plot size and shape and efficient number of replications for field research experiments on wheat yield trial, to determine the effect of plot size on variability in yield, and the efficiency of RCBD relative to CRD.
The results of the study revealed that:
1-Relative efficiency of RCBD was higher than that of CRD
2- Increasing the plot size decreased the variance per basic unit and the coefficient of variation . However, the reduction was not in proportion with the increase in plot size.
4-The relationship between the coefficient of variability (C.V.) and plot size (X) were mathematically expressed by the following equation
C.V. = 18.6 X- 0.680
5- The optimum size of plot ranged from 2 to 4 basic units ( i.e.1.2 m2 to 2.4m2 ).
6-The index of soil variability was 0.68 (intermediate soil heterogeneity)