A Comparison of Flue‐Cured Tobacco Varieties Repeated Over Locations and Years with Implications on Optimum Plot Allocation¹

Abstract

Synopsis Variety ✕ environment first order interactions were small and nonsignificant for most traits studied. But the interaction of variety ✕ location ✕ year was highly significant although small in relation to the variety component for most of the characters. From a comparison of theoretical variances of treatment means with varying plot allocations, adequate information on the relative performance of tobacco varieties in North Carolina can be estimated from data obtained in 2 years, at each of 5 locations with 3 replications.

The Analysis of a Series of Wheat Varietal Trials1

“…It is clear from Table 6 and Figure 1 that, if it is desired to observe the behaviour of wheat varieties or strains over a certain area, the optimum allocation is one replication per location and to increase the number of locations indefinitely within the limits of the research programme. This finding is in close agreement with those of Sprague and Federer (1951) and Jones, Matzinger and Collins (1960).…”

“…The overseas literature on efficiency of lattice designs has been reviewed by Eancroft and Smith (1949), Knowles (1952) and AUard (1952). I n many experiments with corn, soybeans and small grains, lattice designs have shown gains in efficiency averaging 40% or more over randomized blocks.…”

Comparison of shifted multiplicative model, rank correlation, and biplot analysis for clustering winter wheat production environments

“…Horner and Frey (1957) used classical variety 9 location interaction mean squares to group locations based on locations that had minimum interactions. Jones et al (1960) used variance component estimates to determine the optimum numbers of plots, locations, and years in tobacco (Nicotiana tobacum L.) cultivar testing. Guitard (1960) used correlation of yield at pairs of locations as means of grouping locations.…”

Optimum allocation of plots to years, seasons, locations, and replications, and its application to once-over-harvest cucumber trials

“…Therefore, researchers commonly test such genotype x environment interactions to decide whether data need be collected over more than one location, year, or season (e .g., Jones et al ., 1960 ;Miller et al ., 1959) . A few have explored the matter of whether one should prefer more years and/or locations, or more replication .…”