ISSN:
1573-5060
Keywords:
optimum grid size
;
trial field heterogeneity
;
nearest neighbour correction
;
mass selection
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary In unreplicated field trials a correction for soil heterogeneity is easily achieved by ‘gridding’, i.e. by expressing the observations as deviations from a local average. This paper investigates the problem of determining the optimum size of such a neighbourhood to be used in a moving average. The optimum grid size depends on two parameters, i.e. the ‘coarseness’ of the spatial variation of the trial field and the ratio of genotypic vs. non-genotypic variance. In general these parameters are not known to the breeder. We introduce a method for estimating these parameters from the data. From these estimates the optimum grid size can be obtained using tables presented in this paper. The method has been evaluated by applying it to a series of simulated data. It turned out that the agreement between estimated and true optimum grid size was satisfactory in these simulations. Some theoretical aspects of the results are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00037102
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