The use of uniformity data in the design and analysis of cotton and barley variety trials

The results of two uniformity trials, one in furrow-irrigated cotton, the other in barley, are presented and the yield data analysed. The two data sets, while both showing significant row and column effects, exhibited markedly different types of variation over the test area. The cotton data were more uniform and had stronger trends in columns and rows. There was a strong autocorrelation between plots in the barley data which was not evident in the cotton data. These results support the current preferences of cotton breeders for row and column designs and of barley breeders for neighbour designs when conducting variety trials in the field.